The fictional and deadly Jurassic Park has nothing on the real-life Dinosaur Cove on the southern tip of Victoria, Australia. Using bones from the fossil-filled hotspot, a team of paleontologists have confirmed that pterosaurs—more commonly known as pterodactyls—flew over Australian skies as far back as 107 million years ago. Their findings are detailed in a study published May 31 in the journal History Biology.

[Related: This pterosaur ancestor was a tiny, flightless dog-like dinosaur.]

The team examined two pieces of prehistoric bone that were extracted from Dinosaur Cove over 30 years ago. The bones belonged to two different pterosaurs, and were examined by experts from Curtin University in Perth and Melbourne’s Museums Victoria. A partial pelvis bone belonged to a pterosaur with a wingspan over 6.5 feet, and the smaller wing bone belonged to a juvenile pterosaur. These bones turned out to be the oldest remains of the giant winged reptiles ever recovered in Australia, which is better known for its larger sauropod fossils. 

Closely related to dinosaurs, pterosaurs soared through the skies during the Mesozoic Era, about 252 million years ago.

“During the Cretaceous Period (145–66 million years ago), Australia was further south than it is today, and the state of Victoria was within the polar circle—covered in darkness for weeks on end during the winter. Despite these seasonally harsh conditions, it is clear that pterosaurs found a way to survive and thrive,” study co-author and Curtin University PhD student Adele Pentland said in a statement. 

According to Pentland, remains of pterosaurs are a rare find worldwide. Even fewer remains have been discovered at regions that were once high paleolatitude locations, including Victoria. She told CNN that less than 25 sets of pterosaur remains from four species have been found in Australia since the 1980s, compared to more than 100 sets in countries like Argentina and Brazil.  

“So these bones give us a better idea as to where pterosaurs lived and how big they were. By analyzing these bones, we have also been able to confirm the existence of the first ever Australian juvenile pterosaur, which resided in the Victorian forests around 107 million years ago,” said Pentland.

[Related: The biggest animal ever to fly was a reptile with a giraffe-like neck.]

The specimens were found in the 1980s in a Dinosaur Cove expedition led by paleontologists Tom Rich and Pat Vickers-Rich. Their discovery of big-eyed dinosaurs along this area of coastline helped spark a major shift in how dinosaurs were more generally perceived. These “dinosaurs of darkness” gave paleontologists a glimpse of survival without sunlight and reframed questions about whether dinosaurs were warm-blooded creatures. 

“These two fossils were the outcome of a labor-intensive effort by more than 100 volunteers over a decade,” Tom Rich said in a statement. “That effort involved excavating more than 60 meters [196 feet] of tunnel where the two fossils were found in a seaside cliff at Dinosaur Cove.”

The biggest pterosaur scientists know of so far is Quetzalcoatlus northropi, which was found in Texas. Since everything is bigger in Texas, this pterosaur had a wingspan of about 32 to 36 feet. Australia’s largest pterosaur is the Thapunngaka shawi. It was discovered in 2021 by a team from the University of Queensland and boasts a wingspan of roughly 22 feet. 

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A dinosaur specimen unearthed in Castellón, Spain in 2011 is likely a brand new species and genus of spinosaur, a family of dinosaurs whose fossils have been found in Europe, Asia, South America, and Asia. The new findings were published May 18 in the journal Scientific Reports. 

[Related: What was going on inside of this spinosaur’s brain?]

This new species is named Protathlitis cinctorrensis—which comes from the Greek word for “champion” in reference to football club Villarreal C.F. ‘s Europa League win in 2021.

“Three of the authors of this paper live in Villarreal, and with the club’s centenary this year, we wanted to recognise its work both on and off the pitch by naming a dinosaur genus after it,” co-author and Jaume I University paleontologist Andrés Santos‑Cubedo, said in a statement. 

The discovery, alongside another the uncovering of a moderately sized dinosaur named Vallibonavenatrix cani, suggests that the Iberian peninsula  could have been a very diverse area for medium-to-large bodied spinosaurid dinosaurs. 

Spinosaurs were carnivorous theropod dinosaurs that were typically large and stood on two feet. Some of the better known spinosaurids include the crocodile-mouthed 4,000 pound Baryonyx and Spinosaurus, who might be recognizable from its fictional fight with Tyrannosaurus in Jurassic Park III. Many of these unusual 13 to 22 ton dinos stalked ancient riverbanks preying on large fish and lived a different lifestyle than more familiar theropods, such as Allosaurus and Tyrannosaurus.

“The spinosaurs are quite special theropods. They ate fish and lived in and around water, but there’s a lot of debate about just how aquatic they were,” Cassius Morrison, a co-author of the study and PhD student from the UK’s Natural History Museum, said in a statement. “Some scientists suggest they were like herons, snapping up fish while wading, while others think they were more like a penguin, and could move underwater to hunt fish. Suchomimus seems to be more like a heron, while Baryonyx and Spinosaurus had higher bone density which might mean they could have spent time underwater.”

Spinosaurs are believed to have originated in Europe before moving to Africa and Asia sometime during the Late Cretaceous, but the evidence of their existence in present-day Spain is primarily based on fossilized tooth remains.  

In this study, a team of paleontologists analyzed a right jaw bone, one tooth, and five vertebraediscovered in the Arcillas de Morella Formation in eastern Spain. This formation is known for containing fossils of Iguanodon and its relatives and titanosaur-like dinosaurs.

[Related: Spinosaurus bones hint that the spiny dinosaurs enjoyed water sports.]

The fragments were dated to between 127 and 126 million years ago, during the late Barremian or Early Cretaceous period. The team estimates that the new specimen was around 32 to 36 feet long—about the length of a telephone pole.  

The team compared this newly-named specimen to data on other spinosaurs to figure out its evolutionary relationship to other species within the family of dinosaurs. They believe that this new dinosaur appeared in the Early Cretaceous in a large area of land in the Northern hemisphere called Laurasia. 

“Our research demonstrates that two subfamilies of spinosaur occupied western Europe during the Early Cretaceous (145-100 million years ago) before later migrating to Africa and Asia,” Andrés said. “Baryonyx-like spinosaurs became dominant in Europe, while Spinosaurus-like spinosaurs were most abundant in Africa.”

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Everything we’ve learned about dinosaurs essentially comes from fossils. But million-year-old rocks and bones have left a few hulking gaps in our understanding of the prehistoric world. Dinosaur Mysteries digs into the more secretive side of the “terrible lizards,” and all the questions that keep paleontologists up at night.

WE ARE IN THE MIDDLE of history’s greatest fossil rush. Forget about the 19^th-century Bone Wars or the early 20^th-century rise of US museums—paleontologists today are finding more dinosaurs faster than before. On average, they name a new nonavian dinosaur species every two weeks. Some of this year’s fresh arrivals include the long-necked herbivore Chucarosaurus, the duckbill Malefica, and the dome-headed Platytholus.

Despite this incredible rate of discovery, however, plenty of dinosaurs are missing from the paleontological history we’re trying to piece together.

If dinosaur seekers had their druthers, Earth’s geology would look something like an onion. Experts would work through perfectly stacked layers of sedimentary rock that contain comprehensive records of all the species that lived in ancient habitats through time. But such good fortune has eluded scientists. Since the 1800s, geologists and paleontologists have recognized that the fossil record is uneven and sporadic, made up of sediment that accumulated in environments such as streams, oceans, and dune-covered deserts. Most living things were eaten or decayed long before they could become fossilized.

Circumstances have to be just right for a fossil to form. The most ideal settings include relatively wet lowlands where rivers, streams, and other flowing waters could carry the requisite sand and silt to cover bodies. The blanket of sediment helped keep fossils-to-be from being nibbled on by scavengers or destroyed by the elements. As sediment turned to stone, mineral-laden water trickled through the encased body and replaced bone and sometimes soft tissues in a process called permineralization. The nature of the reaction varied from case to case, affected by everything from the size of the dinosaur to the local environment. This explains why we find some prehistoric creatures as partial, jumbled skeletons and others as delicately preserved fossils surrounded by feathers with not a bone out of place. 

In the end, paleontologists need to work with a fraction of a fraction of life’s story. Even some of the best fossil-hunting spots in the world are far from perfect. Consider the gorgeous banded rock layers of Dinosaur Provincial Park in Alberta, Canada, a hotspot for the discovery of stunning Late Cretaceous species such as the crested duckbill Lambeosaurus and the toothy tyrannosaur Gorgosaurus. In a 2013 review of fossils discovered in the park, paleontologists found that dinosaurs that weighed more than 130 pounds are often found at about 78 percent completeness while those below 130 pounds are usually found at about 7.6 percent completeness. (Paleontologists can often differentiate species even from such limited remains based on subtle anatomical traits that experts catalog over time.) Evidently, ancient ecosystems were much harsher on small specimens, masking how numerous they were in thriving times.

The fossil record runs rampant with sampling biases as well. Paleontologists come into the field with their own ideas of what to look for, and many are motivated to study megafauna, which hold more public allure and pose less of a challenge to excavate. A little more than a century ago, when paleontologists were beginning to search Alberta’s 75-million-year-old rocks, the big dinosaurs were much easier to find. Museums—both in the province and in faraway cities like New York—were hungry for near-complete, showstopping reptiles to lure in visitors. No surprise then that the same 2013 assessment from Dinosaur Provincial Park found it took paleontologists an average of 33.6 years to discover and name species above the 130-pound threshold and 65.9 years for those below.

The pattern holds for other dinosaur-bearing rocks, like the famous multistate Hell Creek Formation that preserves the last days of the dinosaurs in western North America. Even though paleontologists have named small dinosaurs when they’ve happened across their fossils, experts have been actively considering the more diminutive reptiles only in the past decade or so.

Of course, it’s a wonder that we know about any dinosaurs at all. Every single fossilized skeleton or footprint has beaten long odds to tell us about ecosystems that we’ll never get to experience directly. Details of how these ancient habitats changed are critical to debates on whether dinosaurs were flourishing or struggling as the great Age of Dinosaurs approached its closing act 66 million years ago.

For example, paleontologists used to wonder why there seemed to be far more dinosaur species roaming western North America 75 million years ago than 66 million years ago, just prior to the K/Pg extinction that decimated them. Some experts reasoned that the creatures were already in decline. But when researchers looked at how prehistoric habitats shifted during that 9-million-year window, they found that environments better at preserving fossils diminished over time. A warm, shallow sea that divided North America drained off the continent, taking with it the wet, marshy lowlands that immortalized dinosaurs so extensively. So there were probably more dinosaur species running around the continent 66 million years ago than we’ll ever know about, a gap created by changes to the land itself.

So where would these missing fauna have dwelled? There’s every reason to think that dinosaurs clambered around ancient mountain ranges—but mountains are hotspots of erosion, not deposition, so the accumulations of sediment needed to preserve dinosaur bodies weren’t present there. The erosion problem also applies to some deserts, like the one in modern-day Arches National Park. Even though it’s perfectly natural to think of dinosaurs wandering between the expanses of bright sandstone, these landscapes were too dry and disintegrated for dinosaurs to be buried and fossilized in them.

It’s also entirely possible that some “rare” species in well-documented fossil beds were transported there by the elements after death. Think of the heavily armored ankylosaurs that were swept out to burials at sea, or the long-necked sauropods that dwelled in the hills but are known by the bones washed into cave systems, where they were buried. Fossil beds often represent where organisms became preserved, not necessarily where they lived.

Because the Earth is not an onion, much of the fossil record remains uneven and unexposed. While somewhat dated now, one 2006 estimate proposed that more than 70 percent of discoverable dinosaur species are still hidden beyond detection.

Much of what we’ve learned about the dinosaur story comes from the later parts of the Triassic, Jurassic, and Cretaceous. We have way less information on the middle of each Mesozoic period, times when new dinosaur dynasties were forming and the ecosystems they thrived in were evolving with them. When experts uncover these animals, they enrich our knowledge of these mysterious times in dinosaur history. In 2019, for example, paleontologists described the sharp-toothed Asfaltovenator from the Middle Jurassic in Argentina. The species offers some context for the rise of the world’s first truly giant carnivores, like Allosaurus. It’s in these middle chapters that we stand to learn the most—to learn about the dinosaurs that are most likely to change and challenge what we think we know about a world millions of years ago.

We hope you enjoyed Riley Black’s column, Dinosaur Mysteries. Check back on PopSci+ in June for the next article.

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A recent discovery sounds like the beginning of another Jurassic Park reboot—but this time beetles are taking center stage instead of mosquitoes. These new fossils preserved in amber show evidence that beetles fed on dinosaurs about 105 million years ago, according to a study published April 17 in the journal Proceedings of the National Academy of Sciences (PNAS).

[Related: Entombed in amber, this tiny crab hails from the age of dinosaurs.]

The most impressive and complete specimen was found in the amber deposit of Rábago/El Soplao in northern Spain. The amber contains shedded fragments–or molts–of small beetle larvae tightly surrounded by some pieces of downy feathers. The feathers once belonged to an unknown theropod dinosaur that was either avian or non-avian. Theropods that flew and those that were more Earth-bound typically shared indistinguishable feather types during the Early Cretaceous period. According to the team, the feathers do not belong to modern birds, since that group of animals appeared roughly 30 million years later during the Late Cretaceous. 

On Earth today, vertebrates and arthropods, like today’s ticks and lice, have a complex ecological relationship that has likely coexisted for more than 500 million years. The interactions between the two are believed to have shaped both vertebrate and arthropod evolutionary history, but evidence of arthropod-vertebrate relationships is still extremely rare in the fossil record, according to the team on this study. 

They found that the larval molts preserved in this study were related to modern skin beetles, or dermestids. These beetles feed on organic materials that decay over time, sometimes bothering dried museum specimens tucked away in closets. However, dermestids do play a key role in recycling organic matter, commonly living in birds nests and in places on mammals where hair, skin, or feathers accumulate.

The authors found that some of the feather portions and other remains were in intimate contact with the molts of the dermestid beetles and have some evidence of damage or decay. 

“This is hard evidence that the fossil beetles almost certainly fed on the feathers and that these were detached from its host,” study co-author and Geological and Mining Institute of Spain of the Spanish National Research Council geologist Enrique Peñalver said in a statement. “The beetle larvae lived—feeding, defecating, molting—in accumulated feathers on or close to a resin-producing tree, probably in a nest setting. A flow of resin serendipitously captured that association and preserved it for millions of years.” 

[Related: These beetles sniff out fungus-infected trees to find their next target.]

It is still unclear if the feathered theropod host benefited from the beetle larvae feeding on detached feathers and that it could have occurred in a nest setting, where the host was sitting on eggs.  

“However, the theropod was most likely unharmed by the activity of the larvae since our data show these did not feed on living plumage and lacked defensive structures which among modern dermestids can irritate the skin of nest hosts, even killing them,” co-author and paleobiologist from Oxford University Museum of Natural History Ricardo Pérez-de la Fuente said in a statement.

Three other pieces of amber that had isolated beetle molt that were in a different stage of the beetle life cycle were also studied, which allowed better understanding of the role that their feathery diet played.

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A dinosaur skull found in Queensland, Australia has the exciting honor of being dubbed Australia’s first nearly complete sauropod skull. 

Research published April 12 in the journal  Royal Society Open Science describes the 19.6 inch long skull, and details that the find was from a species Diamantinasaurus matildae (D. matildae). Diamantinasaurus is a member of the group Sauropoda, which also includes the more famous Brachiosaurus and Brontosaurus and are known for small heads, long necks and tails, and barrel-like bodies.  

[Related: Cushy feet supported sauropods’ gigantic bodies.]

The dinosaur, nicknamed ‘Ann,’ was discovered by the Australian Age of Dinosaurs Museum in 2018 near Winston in central Queensland. Ann is the third fossil specimen of D. matildae to have been discovered by this museum, and the fourth specimen overall. It lived in Australia over 100 million years ago and fell under the titanosaur group– a category of sauropods that included the largest animals to live on land in Earth’s history. D. matildae was a middle size sauropod, with the largest members reaching close to 131 feet long and over 170,000 pounds. Sauropods were also herbivores, subsisting entirely on a diet of plants. 

The team on this study said that it is rare to find a sauropod skull at all, especially one so well-preserved. It is only the fourth specimen of D. matildae ever found and the analysis of this first nearly complete skull is helping scientists learn more about the animal’s feeding habits, relationship to other sauropod dinosaurs, and physical anatomy. According to the team, Ann is not only the first sauropod dinosaur found in Australia that includes most of the skull, it also is the first Diamantinasaurus specimen to preserve a back foot.

“In analyzing the remains, we found similarities between the ‘Ann’ skull and the skull of a titanosaur called Sarmientosaurus musacchioi, which lived in South America at about the same time as Diamantinasaurus lived in Queensland. These include details of the braincase, the bones forming the back end of the skull near the jaw joint, and in the shape of the teeth (which are conical and curved),” co-author and Curtin University paleontologist Stephen Poropat said in a statement. 

[Related: This dinosaur’s record-breaking neck defies the laws of nature.]

According to Poropat, the findings support earlier theories that suggests sauropods used Antarctica as a pathway between Australia and South America during the mid-Cretaceous period–between 100 and 95 million years ago.

“Warmer conditions that far south might have been favorable for them. The window between 100 and 95 million years ago was one of the warmest in Earth’s geologically recent history, meaning that Antarctica, which was more or less where it is now, had no ice,” Poropat said. “Similarly, Australia, which was much further south than today, was warmer with less seasonality. In that climate, Antarctica was forested, and might have been an attractive habitat or pathway for wandering sauropods.”

The study suggests that Diamantinasaurus was one of the most ‘primitive’ or not as evolved titanosaurs. Learning more about this species of giant dino might explain why they were so successful until the dinosaurs’ mass extinction.  

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Watching a bird leap around on its crooked legs before it takes off into the air is kind of  like turning back the evolutionary clock and watching a theropod dinosaur. Numerous paleontologists believe that theropod group, which includes the spinosaurus, tyrannosaurus rex, and velociraptor, evolved into the birds we see on Earth today. This would make them the only dino-descendants that survived catastrophic extinction 66 million years ago.

Like birds, theropod dinos also laid eggs, and scientists are beginning to fill in evolutionary gaps by studying the shelly remains. A study published April 3 in the journal Proceedings of the National Academy of Sciences (PNAS) examined the calcium carbonate left behind in the eggs of a funky theropod called Troodon and found that the dinosaurs laid four to six eggs in communal nests. 

[Related: Newly found titanosaur eggs reveal dino nurseries once teemed with baby giants.]

Troodon was a carnivorous dinosaur over six feet long that lived in North America about 75 million years ago. It had some bird-like features, particularly its light and hollow bones, two legs, and fully developed feathery wings. However, the dinosaur’s relatively large size kept it from flying, but it likely ran very fast and caught prey in strong claws. 

Troodon females also laid eggs that are more similar in shape to the asymmetric eggs laid by  modern birds than to the round reptile eggs. Their eggs were blue-green colored like other theropod eggs, and they have been found half buried into the ground. The international team of scientists on this study believes that mother Troodons sat and brooded on them.

To learn more, the team examined the calcium carbonate left behind in some well-preserved Troodon eggshells. They used a method developed in 2019 called “dual clumped isotope thermometry.” 

With this technique, they could measure the extent to which heavier isotopes of oxygen and carbon clump together in carbonate minerals. Isotopic clumping is temperature-dependent, and the prevalence of this clumping helped the team determine the temperature at which the carbonates crystallized. The eggshells were likely produced at temperatures of 107 degrees Fahrenheit and then deduced down to 86 degrees, which is very similar to modern birds. 

[Related: A fossilized egg laid by an extinct, human-sized turtle holds a rare jackpot.]

The team then compared  the isotopic compositions of reptile egg shells (alligator, crocodile, and multiple turtle species) with modern birds (chicken, sparrow, wren, emu, kiwi, cassowary, and ostrich) to see if Troodon was closer to either birds or reptiles. Two different isotopic patterns were revealed. The reptile eggshells have isotopic compositions matching the temperature of the surrounding environment, since they are cold-blooded and form their eggs slowly. Birds leave a recognizable non-thermal signature in the isotopic composition, which is evidence of quick eggshell formation. 

“We think this very high production rate is connected to the fact that birds, unlike reptiles, have a single ovary. Since they can produce just one egg at the time, birds have to do it more rapidly,” study author and geochemist from Goethe University Frankfurt in Germany Mattia Tagliavento said in a statement. 

The team compared these results to the remains of Troodon eggshells and did not not detect the isotopic composition which is typical for birds. According to Tagliavento,  “this demonstrates that Troodon formed its eggs in a way more comparable to modern reptiles, and it implies that its reproductive system was still constituted of two ovaries.”

As a last step, the researchers combined their results with existing knowledge about body and eggshell weight and determined that Troodon only produced only four to six eggs per reproductive phase. They found this observation particularly notable because Troodon nests are typically large and have up to 24 eggs, so the team believes that this means they laid their eggs in communal nests. This communal egg nesting behavior is seen in modern day ostriches.  

“Originally, we developed the dual clumped isotope method to accurately reconstruct Earth’s surface temperatures of past geological eras,” study co-author, geochemist, and developer of the new thermometry method Jens Fiebig, said in a statement. “This study demonstrates that our method is not limited to temperature reconstruction, it also presents the opportunity to study how carbonate biomineralization evolved throughout Earth’s history.”

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Real predatory dinosaurs like the infamous Tyrannosaurus rex may have looked quite a bit different than their movie star counterparts—and not just because they had feathers. Theropods like the T. rex may have also had completely different mouths. Instead of a lipless grin and permanently exposed teeth with their upper jaw hanging over the lower jaw like a crocodile, the T. rex may have boasted scaly lips covering up their teeth.

The details of this possible oral makeover are described in a new study published March 30 in the journal Science. An international team of researchers say that these lips were more similar to lizards and their relative, the tuatara. The tuatara, the last survivors of an order of reptiles that thrived during the age of the dinosaurs, is a rare reptile that is found only in New Zealand that can live up to 100 years.

[Related: What are dinosaur feathers like?]

The team examined the tooth structure, wear patterns, and jaw morphology of reptiles from both lipped and lipless groups. They found that the theropod mouth functionality and anatomy actually resembled lizards more than crocodiles. The study says this similarity implies the T. rex had lizard-like oral tissues, with scaly lips covering up their teeth.   

“Paleontologists often like to compare extinct animals to their closest living relatives, but in the case of dinosaurs, their closest relatives have been evolutionarily distinct for hundreds of millions of years and today are incredibly specialized,” study co-author and Canada’s Royal BC Museum paleontology collections manager and researcher Derek Larson, said a statement. “It’s quite remarkable how similar theropod teeth are to monitor lizards. From the smallest dwarf monitor to the Komodo dragon, the teeth function in much the same way. So, monitors can be compared quite favorably with extinct animals like theropod dinosaurs based on this similarity of function, even though they are not closely related.”

Additionally, therapod lips were likely not muscular, as seen in mammals. Most reptiles have lips that cover up teeth, but can’t be moved independently. Humans and mammals can make all sorts of movements with their lips, like curling them into a snarl or posing with “duck face” in a selfie, but reptile lips can’t. 

The study also found that the tooth wear in lipless animals was different from what has been seen in carnivorous dinosaurs. Dinosaurs also had teeth that were no larger than modern lizard teeth when compared to their relative skull size. The teeth were likely not too big to be covered up by scaly lips. 

[Related: Is T. rex really three royal species? Paleontologists cast doubt over new claims.]

Another more lizard-like feature in theropods was the distribution of small holes around the jaws that supply blood and nerves to dinosaur gums and tissues in the mouth. When modeling mouth closure in lipless theropod jaws, the team found that the lower jaw either had to crush jaw-supporting bones or disarticulate the jaw joint to seal the mouth.

“As any dentist will tell you, saliva is important for maintaining the health of your teeth. Teeth that are not covered by lips risk drying out and can be subject to more damage during feeding or fighting, as we see in crocodiles, but not in dinosaurs,” said co-author Kirstin Brink, a vertebrate paleontologist at the University of Manitoba, in a statement.

According to the team, this prehistoric lip debate has roots all the way back to the nineteenth century, when scientists began restoring dinosaur fossils. It became more prominent when blockbuster films like Jurassic Park and documentaries took to the screen and have since become deeply rooted in popular culture. 

“Curiously, there was never a dedicated study or discovery instigating this change and, to a large extent, it probably reflected preference for a new, ferocious-looking aesthetic rather than a shift in scientific thinking,” paleontologist and co-author Mark Witton from the University of Portsmouth, said in a statement. “We’re upending this popular depiction by covering their teeth with lizard-like lips. This means a lot of our favorite dinosaur depictions are incorrect, including the iconic Jurassic Park T. rex.”

This study provides new insights into how paleontologists can reconstruct both the soft tissues and appearance of extinct species, so that scientists can learn more about how they fed, maintained their tooth health, and even more broad patterns in their evolution. 

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Everything we’ve learned about dinosaurs essentially comes from fossils. But million-year-old rocks and bones have left a few hulking gaps in our understanding of the prehistoric world. Dinosaur Mysteries digs into the more secretive side of the “terrible lizards,” and all the questions that keep paleontologists up at night.

DINOSAURS DOMINATED EARTH. We all know the trope. The stupendous reptiles were so numerous and unique that they claimed a 150-million-year-long chunk of Earth’s history as the Age of Dinosaurs. 

But talking about a single group of organisms “dominating” the planet is silly. For one thing, the only dinosaurs bobbing in the ocean waves were carcasses, washed out by coastal storms.

Oceans have covered the vast majority of our planet for billions of years and contain more than 96 percent of Earth’s water at present. Dinosaurs, so far as we can tell, never made the sea their home. And paleontologists still don’t know why.

If there’s anything more challenging than understanding why a species evolved a particular way, it’s trying to backtrack on the evolutionary roads it didn’t take. Nature is full of invisible barriers and bottlenecks that open and close based on previous change. We usually don’t perceive these biological constraints until we run into a “Why not?” question. And even then, it can be difficult to distinguish between what’s actually impossible and what simply didn’t happen due to coincidence. In the case of the dinosaurs, though, we have a few clues as to why the seas remained beyond their domain.

For the most part, dinosaurs were atrocious swimmers. But it took decades for paleontologists to figure this out as they waited for the right fossil tracks, analyses of dinosaur bone structure, and computer methods capable of estimating the buoyancy of dinosaurs. During much of the 20th century, when experts insulted living reptiles and dinosaurs alike by characterizing the extinct saurians as dimwitted slowpokes, some paleontologists thought long-necked sauropods like Brachiosaurus could only support their weight in water. They also posited that the “duck-billed” dinosaurs, or hadrosaurids, plunged into lakes when tyrannosaurs stalked too near—the only defense herbivores that weren’t covered in armor or horns could have, apparently. Starting in the 1970s, paleontologists realized that fossilized tracks and other clues about the sauropods and duck-bills indicated they lived in terrestrial environments and weren’t adept in water. Not only that, but the relatively few trace fossils made by swimming dinosaurs—scrapes in the sediment from when they kicked their feet—were created by carnivorous dinosaurs, undercutting the idea that water was a refuge for plant eaters. 

A key dinosaurian trait may have prevented the reptiles from getting cozy in the water. The bony respiratory systems of sauropods and theropods show evidence of a unique set of air sacs connected to the lungs and other parts of the respiratory system. These soft-tissue pockets allowed the creatures to breathe more efficiently than mammals by keeping new air constantly flowing instead of relying on distinct inhales and exhales. (Birds have the same feature, with the added benefit that it keeps their skeletons light by filling bony spaces with air.) But when modeling how these air pockets would have affected dinosaurs’ swimming ability, paleontologists found that even large species would have acted like inflatable pool toys—too light for their size to be stable in the water. Adaptations to a life aquatic usually involve denser bones as a form of natural ballast—too much internal air would make dinosaurs work too hard to stay submerged. So much like us, while some dinosaurs could swim, they certainly weren’t diving neck and neck with the prehistoric sea turtles and plesiosaurs.

The same problem comes up for dinosaurs that were once considered skilled swimmers. The sail-backed, roughly 50-foot-long Spinosaurus has a few anatomical hallmarks associated with dipping and diving: Some of its bones seem extra dense, like those of other semiaquatic animals, and its tail is long and eel-esque, like a giant hitched-on paddle. But recent studies have found that Spinosaurus’ airy skeletal structure would have made it unstable in water too, and that the huge sail would have hampered the dinosaur’s ability to chase after prey while submerged. It’s more likely that the creature, once heralded as the world’s first swimming dinosaur, was more of a wader that plodded through the shallows as it tried to ambush fish. While additional evidence might alter the picture, especially because no one has found anything close to a complete Spinosaurus skeleton, for now the dinosaur most closely associated with the water was less aquatic than an alligator.

In all, after more than two centuries of searching, paleontologists have not identified a single dinosaur fossil that definitely spent most of its life at sea. The few specimens dug up from marine sediments—like the beautifully preserved armored Borealopelta from Alberta—represent dinosaurs that perished inland or along the coasts and were washed out to sea by storms or local flooding. Some became food for sharks and marine reptiles; some formed temporary reefs; and some quickly got buried under rock and soil, preserving their scales in place. But there were plenty of other reptiles in the sea—fish-like ichthyosaurs, long-necked plesiosaurs, and mosasaurs that were the ocean equivalent of Komodo dragons—that prove the dominion of dinosaurs was exaggerated. 

Of course, we know that dinosaurs eventually did wander into the water. For example, about 5 million years after the asteroid impact that ended the Cretaceous, the first ancestors of penguins took the plunge. Today, these water-savvy birds “fly” by flapping their wings underwater and sport a variety of adaptations, from hydrophobic feathers to salt-excreting vessels in their bills, that allow them to spend a great deal of their time in the ocean. But they still reproduce on land, shedding yet another clue to why extinct dinosaurs never hit the deep blue.

So far as we know, all dinosaurs laid eggs—from the very first terrible lizard (“dinosaur” translated into Greek) 243 million years ago to the chickadees bouncing around on the sidewalk in the present. Whereas other marine reptiles repeatedly evolved ways to give birth, likely starting with the soft-shelled eggs that some snakes and lizards retain today, dinosaurs don’t seem to have ever evolved a different capability. Or perhaps they did but were so late to the party that the seas were already full of nimble, sharp-toothed reptiles ready to munch on any awkward dino-paddlers. The ancient world of the dinosaurs was one that ended at the shoreline, leaving plenty of space for other creatures to rule the water.

We hope you enjoyed Riley Black’s column, Dinosaur Mysteries. Check back on PopSci+ in May for the next article.

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Over 60,000 years ago, an eagle relative with an almost 10 foot wingspan stalked the skies over southern Australia. Dynatoaetus gaffae (Gaff’s powerful eagle) had talons that could even snatch a koala or small kangaroo for dinner. The massive bird of prey was likely the largest continental eagle the world had ever seen. 

A study published March 16 in the Journal of Ornithology details how a team of fossil hunters from Flinders University in Australia put together this bird’s story. Four large fossilized bones were collected in Mairs Cave southern Australia’s Flinders Ranges  as far back as 1956 and 1969. The authors found an additional 28 bones scattered among the boulders in the site whoch helped them create a better picture of this giant extinct bird. 

[Related: This dragon-like reptile once soared over Australia.]

This now extinct raptor is closely related to Old World vultures that prowled Africa and Asia during the Pleistocene. In today’s fauna, its closest relative is likely the critically endangered monkey-munching Philippine Eagle. During the late Pleistocene Epoch, when giant megafauna like the mammoth roamed the Earth and ice sheets and glaciers were growing, Dynatoaetuswas likely the top avian predator on the planet. 

“It’s often been noted how few large land predators Australia had back then, so Dynatoaetus helps fill that gap,” said study author and Flinders University paleontologist Ellen Mather, in a statement.  “This discovery reveals that this incredible family of birds was once much more diverse in Australia, and that raptors were also impacted by the mass extinction that wiped out most of Australia’s megafauna.”

Dynatoaetus and another recently described smaller bird named Cryptogyps represent a new genera of raptors that are unique to Australia. 

“[Dynatoaetus] was humongous. Larger than any other eagle from other continents, and almost as large as the world’s largest eagles once found on the islands of New Zealand and Cuba, including the whopping extinct 13kg [28 pound] Haast’s eagle of New Zealand,” said Trevor Worthy, a study co-author and paleontologist at Flinders University, in a statement. 

[Related: Giant wombats the size of small cars once roamed Australia.]

Dynatoaetus also coexisted with the Wedge-tailed Eagle, a species that currently lives in Australia. The team says that this has interesting implications.

“Given that the Australian birds of prey used to be more diverse, it could mean that the Wedge-tailed Eagle in the past was more limited in where it lived and what it ate,” said Mather. “Otherwise, it would have been directly competing against the giant Dynatoaetus for those resources.”

Most of Australia’s eagles and vultures like the Dynatoaetus went extinct about 50,000 years ago, along with most of the continents’s megafauna.  One 2020 study found that a possible explanation is extreme environmental change and deterioration (loss of water, increased burning of trees and grass, etc.) that wiped out at least 13 super-sized megafauna species, including the world’s largest wombats and kangaroos.

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Dinosaurs came in all shapes and sizes, but we know they could get pretty darn big. For sauropods, a clade of dinos that roamed the planet from the Early Jurassic all the way to the Cretaceous–Paleogene extinction event, their size was largely reflected in their long necks. But according to new findings, the Mamenchisaurus sinocanadorum uncovered in modern-day China may have been the longest-necked of them all.

In a study published today in The Journal of Systematic Paleontology, an international team of scientists determined that this particular specimen of sauropod had a 49-foot-long neck—that’s six times as long as a giraffe neck. 

“It would require a lot of muscles to hold up a neck that size, and then there’s the question of how it gets air down to the lungs and back up again,” Paul Barrett, a professor at the Natural History Museum in London, said in a press release. “This could support the theory that these necks were a sexually selected feature where only the strongest and fittest dinosaurs that were able to hold up these giant necks in impressive displays were able to mate.” 

[Related: Feisty ankylosaurs clubbed each other with their tails.]

This took paleontologists quite a bit of puzzling—there’s only one Mamenchisaurus sinocanadorum specimen to analyze, discovered in 1987 at a site in the Shishugou Formation in northwestern China. The skeleton only includes the front end of the neck, a rib, some skull bones, and a lower jaw. 

So, how do you measure the entire length of a neck from just a few bones? Well, you have to find a similar species to compare it to. In 2012, the giant sauropod Xinjiangtitan was uncovered in China with an intact 43-foot-long neck. Using an “elementary bit of maths,” Barrett explained, the team was able to look at proportions of the relative’s vertebrae and scale up the incomplete skeleton. What they found was a specimen that could very well be a record-breaker. 

But the team didn’t just figure out how long the dinosaur’s neck was—they prodded at the biomechanics of how such a body part could even exist. Using computer-tomography scanning, the authors found that the hollow vertebrae of the massive sauropod was around 69- to 77-percent air, which is similar to modern-day storks. The authors determined that to protect such a lightweight neck from getting hurt, the dinosaur had 13-foot-long rod-like cervical ribs on either side for stability. 

“Biomechanical studies of the [Mamenchisaurus] neck suggest that it was elevated at only a relatively shallow angle above the horizontal (20 to 30°). However, even at this relatively shallow angle, the extreme length of the neck would still mean that the animal’s head could reach heights of around [25 to 33 feet] above ground level,” co-author Paul Upchurch, a professor of palaeobiology from the University College London, said in a press release. 

[Related: Move over, Stegosaurus, there’s a new armored dino in town.]

The reasons for the long neck—and exact mechanics of how it worked—are still a mystery, but some paleontologists believe they could have evolved so the giant creatures could sit still in one spot and still have access to lots of leafy trees to eat. They could have also allowed the sauropod to shed extra heat by increasing their surface area. 

“It could have also been to do with sexual display or used for neck-butting contests between males fighting over mates and territory, similar to how giraffes behave today,” Barett said. “But we can’t say for sure. At this point, it’s pure speculation as to why they evolved necks of this length.”

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The waters of the 360-million-year-old subcontinent Gondwana were a dangerous place for a swim. A killer, bony fish the length of an adult California sea lion stalked freshwater rivers as a top predator. It was massive—as a new discovery reveals, this was the largest prehistoric bony fish ever discovered in southern Africa. 

Its ferocity is reflected in its name, Hyneria udlezinye (H. udlezinye), which means the “one who consumes others,” in IsiXhosa, an Indigenous language spoken widely in southeastern South Africa where its bones were found.

[Related: One wormy Triassic fossil could fill a hole in the evolutionary story of amphibians.]

“Picture a fish looking a bit like a gigantic alligator. About 8 feet long, but with a more rounded head like the front end of a torpedo,” Per Ahlberg, a paleontologist and zoologist at Uppsala University in Sweden, tells PopSci. Ahlberg is the co-author of a study published February 22 in the journal PLOS One describing the carnivore. “The small eyes are located near the front of the head. In the mouth there were rows of small pointed teeth together with pairs of large fangs, up to a couple of inches tall.”

The specimen was found on the edge of Makhanda, South Africa, at the Waterloo Farm lagerstatte, a fossil site rich in specimens from the Late Devonian world, about 419.2 million and 358.9 million years ago. Co-author Rob Gess, a paleontologist from the Albany Museum and Rhodes University, South Africa has been collecting specimens from the site since 1985, where he has uncovered bones, teeth, and small invertebrates, as well as weeds and plants. 

“This fossil site is globally significant for understanding biogeography of the Late Devonian world as it provides us with the only known window into a polar ecosystem during this pivotal time interval,” Gess tells PopSci.

But the remains of bigger things lurk there, too. H. udlezinye belongs to an extinct group of lobe-finned fish called the Tristichopterids. Late in the Devonian period, one branch of the Tristichopterid family developed into a cluster of giants. These huge Tristichopterids possibly arose in Gondwana, the ancient supercontinent, before migrating to Euramerica. The study authors determined that H. udlezinye is closely related to its North American cousins by comparing it with specimens of Hyneria lindae found in Pennsylvania’s Catskill Formation. The authors say that this supports the idea that all of these giants originated in Gondwana and adds a piece to their evolutionary puzzle.

[Related: Tiktaalik’s ancient cousin decided life was better in the water.]

All other fish in the Tristichopterid group were largely believed to live in the more tropical, or central, regions of the subcontinent, but these specimens were found south of where the paleoantarctic circle (our southern polar circle) was at this time. This suggests a more global distribution of the fish, from the equator down closer to the poles. 

H. udlezinye was a ferocious predator that would have eaten most of the larger kinds of fish—including the relatives of modern coelacanths—and four-legged animals found near the site. Their body shape also suggests that they were likely “lie-in-wait predators,” who quietly hid and then quickly lunged to grab passing prey with fanged jaws. 

As fearsome as it must have been, this apex predator was not completely invulnerable. The Tristichopterids, along with many other species of lobe-finned and armor-plated fish, “went extinct in the End Devonian Mass Extinction event 358.9 million years ago—the second of the big five global extinction events that radically altered the make-up of life on Earth,” explains Gess.

Learning more about the Denovian world can help scientists better understand not only the flora and fauna that went extinct during this mass extinction event, but also more about evolution and even ourselves as humans.

“This was a particularly interesting time in the history of the planet, when life had recently become established on land and was diversifying rapidly,” Ahlberg says. “Our own distant ancestors”—the earliest animals with four limbs, or tetrapods—“emerged out of the water during the Devonian.” 

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Roughly 125 million years ago, when the world was warmer, more humid, with higher sea levels, Spinosaurs were a genus of theropod (or “beast-footed”) dinosaurs. These unusual 13 to 22 ton dinos were known for their long, crocodile-like jaws and cone shaped teeth. They stalked riverbanks preying on large fish and lived a different lifestyle than more familiar theropods, such as Allosaurus and Tyrannosaurus. Some spinosaur species include Spinosaurus aegyptiacus and Spinosaurus marocannus and many specimens have been found in northern Africa.

But, paleontologists still don’t know quite as much about these “enormous river monsters.”

An international team of scientists has reconstructed the brains and inner ears of two spinosaur specimens found in England.  Not only does reconstructing a dino brain sound awesome, it’s also a step in understanding how these theropod dinosaurs interacted with their environment. The study was published February 13 in the Journal of Anatomy.

[Related: Cushy feet supported sauropods’ gigantic bodies.]

In order to get a better understanding of how their brains and senses evolved, the team scanned fossils of two different theropod species—Baryonyx found in Surrey, in southern England and Ceratosuchops, which was found on the Isle of Wight. Baryonyx was about 32 feet long and bore the same crocodile-like mouth. Ceratosuchops has been nicknamed the “hell heron,” and was about 27 feet long.

These specimens are special because they are two of the oldest spinosaur fossils that contain the dinosaur’s braincase material. The team was able to digitally reconstruct the internal soft brain tissues that rotted away over time.

They found that the olfactory bulbs—responsible for processing smells—weren’t particularly developed. However, their ears were likely attuned to picking up low frequency sounds. They also found that the parts of the brain that keep the head stable and eyes fixed on prey were possibly less developed than they were in more specialized spinosaurs that evolved later on.

“Despite their unusual ecology, it seems the brains and senses of these early spinosaurs retained many aspects in common with other large-bodied theropods – there is no evidence that their semi-aquatic lifestyles are reflected in the way their brains are organized,” said Chris Barker, a PhD student at the University of Southampton and co-author, in a statement.

One of the team’s interpretations of this evidence is that the ancestors of spinosaurs already had sensory adaptations and brains that were suited to catching fish. To become more adept at living in a specialized semi-aquatic lifestyle, they needed to evolve an unusual snout and teeth.  

[Related: Spinosaurus bones hint that the spiny dinosaurs enjoyed water sports.]

“Because the skulls of all spinosaurs are so specialized for fish-catching, it’s surprising to see such ‘non-specialised’ brains,” said University of Southampton paleontologist and co-author Darren Naish, in a statement. “But the results are still significant. It’s exciting to get so much information on sensory abilities – on hearing, sense of smell, balance and so on – from British dinosaurs. Using cutting-edge technology, we basically obtained all the brain-related information we possibly could from these fossils.”

One of the most powerful CT scanners in Great Britain scanned the braincase of the Cretaceous era-Ceratosuchops, and a model of its brain will be on display alongside of its bones at Dinosaur Isle Museum on the Isle of Wight.

“This new research is just the latest in what amounts to a revolution in paleontology due to advances in CT-based imaging of fossils,” said co-author Lawrence M. Witmer, professor of anatomy at the Ohio University Heritage College of Osteopathic Medicine, in a statement. “We’re now in a position to be able to assess the cognitive and sensory capabilities of extinct animals and explore how the brain evolved in behaviorally extreme dinosaurs like spinosaurs.”

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“AND THAT’S HOW YOU MAKE a baby dino-sawr.” I wish it were as easy as Mr. DNA made it sound in the first Jurassic Park movie. Paleontologists have learned an astonishing amount about the “terrible lizards” in the past 200 years, from the colors of their feathers to the illnesses that left them with dino-sores, but there is one area of their lives that we know shockingly little about. We can be sure dinosaurs had sex to make generation after generation of reptiles, but thanks to the rarity of soft tissues in the fossil record, we are still left stumped by how they did it exactly. 

Peeking into the science of prehistoric proliferation isn’t voyeuristic. Sex is something life on Earth does with creativity and gusto. It’s the way that many organisms combine their individual genes and inevitably create new variations. These new traits—a different shade of scale, longer wing feathers, better resistance to infection—make a difference in survival and who mates with whom to pass on some of those traits. When we’re talking about evolution, we’re often just breaking down sex and its consequences. So as far as non-avian dinosaurs are concerned, we’re only just beginning to dig in.

A single fossil discovery could almost solve the problem in an instant. Paleontologists have found other prehistoric creatures whose quest for the “little death” became a more permanent one. In 2012 they reported on fossil turtles preserved in the middle of mating. The next year, a different research team reported on insects called froghoppers smooshed in the throes of arthropod passion 165 million years ago. In 2015, experts announced that 385-million-year-old armored fish had complementary fin modifications for mating, making them among the earliest known vertebrates to have penetrative sex. Which means it’s not impossible that a pair of Velociraptor or other dinosaur was preserved in flagrante in strata, maybe even with some of those mysterious soft parts.

But experts have yet to get lucky. The fossil record is incomplete and unevenly preserved, and it’s doubtful that universities or government funding agencies are going to start signing checks to search for how dinosaurs made the bed rock. Paleontologists have to work with the information they have without making museum security guards wonder why they’re taking such an interest in the back half of that Apatosaurus skeleton.

The nature of dinosaur reproductive organs is as good a place to start as any. Just last year, scientists announced that they had finally delineated the anatomy of a dinosaur’s butthole. A specimen of the horned Psittacosaurus found in Mongolian rocks from more than 100 million years ago came intact with the skin and some internal details for the area just under the tail. The parrot-beaked reptile had a cloaca—a single-use external opening at the end of the urinary, excretory, and reproductive tracts. (No wonder the term means “sewer” in Latin.) But the find confirms what paleontologists already expected based on the fact that both birds—which are living dinosaurs—and crocodiles have cloacae. And that might tell us something about what that vent held.

Dinosaur genitals certainly were not one-size-fits-all. During the Triassic, Jurassic, and Cretaceous periods, wildlife thrived in all sorts of shapes and sizes, which probably means dinosaur sex organs varied too. What was true for Psittacosaurus may not have held for Tyrannosaurus, Stegosaurus, or any other species. (In fact, famous as T. rex is, we don’t have any direct evidence of how they courted, mated, laid eggs, or nested, leaving us to hypothesize details from various relatives.) But we can be reasonably confident that non-bird dinosaurs had clitorises and phalluses, which is also a great statement to drop into the middle of cocktail party chatter.

With the exception of intersex reptiles, female alligators and crocodiles have a clitoris behind their vent, while males have a phallus. Many species of modern birds, too, have similar structures. Emus, ducks, and others have phalluses, and females of some avian species have clitorises—although the sexism prevalent in biology has kept us from drawing a full account. But the fact that the closest living relatives of Brachiosaurus and family had clitorises and phalluses hints that many prehistoric dinosaurs did too. In fact, sometimes it’s difficult to imagine how these beasts could have mated without organs to bridge the distance. While some songbirds bring their gametes into contact through a short “cloacal kiss,” it’s unlikely that amorous Ceratosaurus did the same with their huge bodies and lengthy tails.

But there’s more to sex than mechanics, of course. While we wait for a juicy fossil discovery, we can say a little bit about the moments leading up to mating in the Mesozoic. In recent years paleontologists have begun to reassess the horns, spikes, plates, and other “bizarre” structures that make long-dead reptiles endlessly fascinating. Most of these structures were once seen as weapons for attack and defense. Now, many of them seem to be biological signposts that only developed as the animals matured—sexual selection signals that were meant to be read by potential mates and rivals. So, an Ankylosaurus dotted with bony armor from its eyelids to its tail club didn’t evolve that look to only defend against tyrannosaur teeth: that was Late Cretaceous fashion brought about by season after season of dinosaur-mating choices.

Researchers have even found some of the places where singles flaunted their assets. They’ve used several fossil sites in Colorado to document where Allosaurus-like dinosaurs scraped at the ground with their taloned hind feet, scratching and kicking to impress other members of their kind just as puffins and other birds do today. Dinosaur displays were probably as unique and varied as their species were, but these tracks indicate that some big carnivores preferred a soil-spattered shuffle to start the romance. Perhaps, as fossil track expert Anthony Martin mused in his book Dinosaurs Without Bones, one day an expert or amateur will find tracks of a mating pair that will help us break down the dance steps like an archaic TikTok video.

As long as we have to rely on rare clues from a fragmentary record, the sex lives of dinosaurs will always be incomplete. Whatever we might still learn is held close by the rock. Rather than being a silly aside, however, the question of how dinosaurs reproduced is part of their enduring success story, a truly vital part of ancient lives that we can just barely touch through tooth and bone. They didn’t make it for more than 200 million years without doing something right. 

Read more PopSci+ stories.

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With some species clocking in the same size as present day whales, titanosaurs were some of the largest dinosaurs to ever walk the Earth. Living from the Late Jurassic Epoch (about 163.5 million to 145 million years ago) up until the end of the Cretaceous Period (roughly 145 million to 66 million years ago), these herbivorous sauropod dinosaurs ranged from 23 to 85 feet long, depending on the species.

Now, a discovery of these dinosaurs in one of their smallest forms is revealing intimate details about the lives of these gentle giants. In excavations between 2017 and 2020, a team of researchers discovered more then 250 fossilized eggs in 92 nesting sites in central India’s Lameta Formation The findings are detailed in a study published January 18 in the open-access journal PLOS ONE.

[Related: A fossilized egg laid by an extinct, human-sized turtle holds a rare jackpot.]

The Lameta Formation in the Narmada Valley is well known for fossils of dinosaur eggs and skeletons from the Late Cretaceous Period. Scientists first found dinosaur eggs in the region in the 1990s, and this study focuses on on a nesting site in the Dhar district.

“Together with dinosaur nests from Jabalpur in the upper Narmada valley in the east and those from Balasinor in the west, the new nesting sites from Dhar District in Madhya Pradesh (Central India), covering an east-west stretch of about 1000 km [621 miles], constitute one of the largest dinosaur hatcheries in the world,” said Guntupalli V.R. Prasad, a study co-author also from the University of Delhi, in a statement.

The team closely examined the eggs, which clocked in at roughly six inches in diameter, and identified six different egg-species, called oospecies. The variation suggests that there was a higher diversity of titanosaur species than is currently represented by the fossilized skeletal remains found in this region.

“Our research has revealed the presence of an extensive hatchery of titanosaur sauropod dinosaurs in the study area and offers new insights into the conditions of nest preservation and reproductive strategies of titanosaur sauropod dinosaurs just before they went extinct,” said Harsha Dhiman from the University of Delhi, the lead author of the study, in a statement.

The team also believes that titanosaurs buried their eggs in shallow pits similar to present-day crocodiles based on the layout of the nests. They even found a rare case of an ovum-in-ovo (or egg-in-egg), which indicates that titanosaur sauropods had reproductive physiology that is similar in modern birds and crocodiles and possibly laid their eggs sequentially.

Since many nests were found in the same area, the dinosaurs may have exhibited the colonial nesting behavior seen in present day birds like great egrets, brown pelicans, and cormorants. However, the close spacing of the nests didn’t leave a lot of room for adult dinosaurs, which supports the idea that adult titanosaurs left their newborns to fend for themselves, unlike modern birds who sit on their eggs to incubate them.

[Related: This newly discovered titanosaur had heart-shaped tail bones.]

Historically, the details of dinosaur reproductive habits have been a bit difficult to determine. Fossil nests can help and the ones from this study offer insight into how some of the largest dinosaurs in history reproduced, evolved, and lived just before going extinct.

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Deep in the stone at the Berlin-Ichthyosaur State Park (BISP) in Nevada’s Humboldt-Toiyabe National Forest, many 50-foot-long ichthyosaur (Shonisaurus popularis) specimens lay petrified and frozen in time. This order of extinct marine reptiles (and Nevada’s state fossil) looked like a chunky dolphin and lived during the late Triassic age, roughly 237-227 million years ago.

New research also suggests that the predator may have performed similar migrations to modern whales. Today’s blue and humpback whales make annual migrations thousands of miles across oceans to breed and give birth in regions where predators are scarce. Many of these whales gather together year after year along the same stretches of coastline.

[Related: These ancient, swimming reptiles may have been the biggest animals of all time.]

Shonisaurus may have done something very similar. An international team of researchers published their findings Monday in the journal Current Biology, explaining how at least 37 of these marine reptiles died in the same location—a question that has stumped paleontologists for more than 50 years.

“We present evidence that these ichthyosaurs died here in large numbers because they were migrating to this area to give birth for many generations across hundreds of thousands of years,” said co-author and Smithsonian National Museum of Natural History curator Nicholas Pyenson, in a statement. “That means this type of behavior we observe today in whales has been around for more than 200 million years.”

Some paleontologists have proposed that BISP’s ichthyosaurs died in a mass stranding event similar to the ones seen in whales today, or that a harmful algal bloom may have poisoned the animals. But these hypotheses do not have strong scientific evidence supporting them.

To try to solve this prehistoric puzzle, the team combined 3D scanning and geochemistry and combed through archival materials, photographs, maps, and field notes, for shreds of evidence.

Within BISP is a barn-like building that researchers call Quarry 2, which houses partial skeletons from an estimated seven individual ichthyosaurs that all appear to have died around the same time. 

“When I first visited the site in 2014, my first thought was that the best way to study it would be to create a full-color, high-resolution 3D model,” lead author Neil Kelley, an assistant professor of geology at Vanderbilt University, said in a statement. “A 3D model would allow us to study the way these large fossils were arranged in relation to one another without losing the ability to go bone by bone.”

The team then collaborated with Jon Blundell, a Smithsonian Digitization Program Office’s 3D Program team member, and Holly Little, informatics manager in the museum’s Department of Paleobiology. Little and Blundell used digital cameras and a spherical laser scanner to take hundreds of photographs and millions of point measurements. These were then stitched together using specialized software to create a 3D model of the fossil bed while the paleontologists on the team physically measured the bones.

“Our study combines both the geological and biological facets of paleontology to solve this mystery,” co-author Randall Irmis, a paleontology professor at the University of Utah and the chief curator of the Natural History Museum of Utah’s Department of Geology & Geophysics, said in a statement. “For example, we examined the chemical make-up of the rocks surrounding the fossils to determine whether environmental conditions resulted in so many Shonisaurus in one setting. Once we determined it did not, we were able to focus on the possible biological reasons.”

Geochemical tests in the rock didn’t reveal any signs that these ichthyosaurs died due to a major environmental event like a harmful algal bloom that would have also disturbed the ecosystem. They expanded their search beyond Quarry 2 to the surrounding geology and fossils that scientists had previously excavated from the area. 

[Related: This whale fossil could reveal evidence of a 15-million-year-old megalodon attack.]

The geologic evidence showed that when the ichthyosaurs died, their bones sank to the bottom of the sea over time instead of collecting along the shoreline, which would have suggested stranding. The area’s mudstone and limestone were also full of large adult Shonisaurus specimens but not as many specimens of other marine vertebrates.

“There are so many large, adult skeletons from this one species at this site and almost nothing else,” said Pyenson. “There are virtually no remains of things like fish or other marine reptiles for these ichthyosaurs to feed on, and there are also no juvenile Shonisaurus skeletons.”

After ruling out the algae and stranding hypotheses, the team found a key clue in tiny ichthyosaur remains among some of the new fossils collected at the park and hiding within older museum collections. Micro-CT x-ray scans and a comparison of the bones and teeth showed that the small bones were embryonic and newborn Shonisaurus.

“Once it became clear that there was nothing for them to eat here, and there were large adult Shonisaurus along with embryos and newborns but no juveniles, we started to seriously consider whether this might have been a birthing ground,” said Kelley.

Additional analysis revealed that the ages of the many fossil beds of BISP were actually separated by at least hundreds of thousands of years, if not millions of years.

“Finding these different spots with the same species spread across geologic time with the same demographic pattern tells us that this was a preferred habitat that these large oceangoing predators returned to for generations,” said Pyenson. “This is a clear ecological signal, we argue, that this was a place that Shonisaurus used to give birth, very similar to today’s whales. Now we have evidence that this sort of behavior is 230 million years old.”

The next step for this research is to look into other ichthyosaur and Shonisaurus sites in North America with these new findings in mind. It will help scientists recreate this ancient world by looking for other breeding sites or places with greater diversity of other species that could have provided rich feeding grounds for this extinct apex predator. 

“One of the exciting things about this new work is that we discovered new specimens of Shonisaurus popularis that have really well-preserved skull material,” Irmis said. “Combined with some of the skeletons that were collected back in the 1950s and 1960s that are at the Nevada State Museum in Las Vegas, it’s likely we’ll eventually have enough fossil material to finally accurately reconstruct what a Shonisaurus skeleton looked like.”

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About 252 to 201 million years ago, roughly 76 percent of all marine and land-based species were wiped off the face of the Earth. The Triassic-Jurassic mass extinction is largely believed to be what helped dinosaurs eventually dominate the landscape, but scientists are still understanding how and why. A new study published Friday in the journal Current Biology, suggests that it was climate change and not competition between species that helped them ascend to the top of the food chain.

[Related: After the dinosaurs, Earth became an all-you-can-eat buffet for snakes.]

The sauropod-like dinosaurs that would become the giant herbivore species seen during the Jurassic (such as Diplodocus and Brachiosaurus) thrived and expanded to new territories as the Earth warmed. These dinosaurs are known for their massive bodies with long tails and giraffe-like necks paired with and a small head.

An team of paleontologists from the United Kingdom, Germany, and Brazil compared computer models of global climate conditions, such as rainfall and temperature, with data on the different locations of dinosaurs during this time period. Their work showed how both sauropods and sauropod-like animals were a winner during this turbulent period on Earth.

“What we see in the data suggests that instead of dinosaurs being outcompeted by other large vertebrates, it was variations in climate conditions that were restricting their diversity,” Emma Dunne, study co-author and paleontologist at Friedrich-Alexander University Erlangen-Nürnberg, said in a statement. “But once these conditions changed across the Triassic-Jurassic boundary, they were able to flourish. The results were somewhat surprising, because it turns out that sauropods were really fussy from the get-go: later in their evolution they continue to stay in warmer areas and avoid polar regions.”

[Related: Cushy feet supported sauropods’ gigantic bodies.]

There is still debate among scientists about the direct cause of this extinction event. Some scientists believe that the climate change and sea level rise resulted from a sudden large release of carbon dioxide that occurred when the supercontinent Pangea began to rift, leading to devastating volcanic eruptions. As the land masses that are now now eastern North America and northwestern Africa began to split apart, up to 100,000 gigatons of carbon dioxide may have been released into the atmosphere. This extra carbon dioxide likely strengthened the greenhouse effect around the world, increasing air temperatures by as much as 18-27 °F.

Further research will go into better understanding the effect of climate change after the dinosaurs took over.

“What we want to do next is use the same techniques to understand the role of climate in the next 120 million years of the dinosaur story,” said Richard Butler, a paleontologist at the University of Birmingham, in a statement.

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When the discovery of a new species of ankylosaur (Zuul crurivastator) was announced, it delighted 80s movie fans the world over due to its resemblance to the monster Zuul from the 1984 classic Ghostbusters. The dinosaur’s name means, “Zuul, the destroyer of shins,” in reference to its 10 foot long tail that was likely used to smash the legs of two legged tyrannosaurs like the Tyrannosaurus rex.

Now, scientists from the the Royal Ontario Museum (ROM), Royal BC Museum, and North Carolina Museum of Natural Sciences have found new evidence for how these tank-like armored dinosaurs used these signature tail clubs. Their study was published today in the journal Biology Letters.

[Related: This new species of dinosaur looks like Zuul from Ghostbusters.]

A very complete and well-preserved fossil of Zuul crurivastator housed at the Royal Ontario Museum has spikes along its flanks that were broken and actually re-healed while the dinosaur was still living. Scientists believed that these injuries were caused from a strike by another ankylosaur’s massive tail club.

The team suggests that ankylosaurs had complex social behavior, potentially battling one another for territorial and social dominance or even engaging in a rutting season for mates the way many animals like deer and elk do. In animals alive today, specialized weapons like the antlers of deer or the horns of antelopes evolved to be used mostly for fighting off members of the same species during battles for territory or mates.

The plant-eating dinosaur lived throughout the United States and Canada during the late Cretaceous Period, about 74-67 million years ago. The Zuul skeleton used in this study was found in the famed fossil-rich Judith River Formation of northern Montana.

Initially, Zuul’s skull and tail had been freed from the surrounding rock, while its body was still enclosed in 35,000 pounds of sandstone. The body was exhumed after years of work, and had most of the skin and bony armor across the entire back and flanks in tact. This gave scientists a remarkable view of what the dinosaur actually looked like when it roamed the Earth.

Zuul’s body was covered in bony plates of different shapes and sizes and the ones along its sides were particularly large and spiky. Some of the spikes near the dinosaurs hips are missing their tips and the bone and horny sheath appears to have healed into a more blunt shape. The team believes that the pattern of these injuries possibly comes from some form of ritualized ankylosaur combat, or jousting with their tail clubs. They also weren’t likely caused by an attacking predator like a T-rex due to the locations of the injuries on the skeleton.

“I’ve been interested in how ankylosaurs used their tail clubs for years and this is a really exciting new piece of the puzzle,” said study co-author Victoria Arbour, Curator of Palaeontology at the Royal BC Museum, in a statement. “We know that ankylosaurs could use their tail clubs to deliver very strong blows to an opponent, but most people thought they were using their tail clubs to fight predators. Instead, ankylosaurs like Zuul may have been fighting each other.”

[Related: Move over, Stegosaurus, there’s a new armored dino in town.]

The back half of the ankylosaur’s tail was stiff and the tip was covered in huge bony blobs, making the tail a pretty fierce sledgehammer-like weapon. The new research shows that the tail clubs could have been used for inter-species combat as well as a defense against bigger predators and that this conflict within the species likely drove their evolution.

“The fact that the skin and armour are preserved in place is like a snapshot of how Zuul looked when it was alive. And the injuries Zuul sustained during its lifetime tell us about how it may have behaved and interacted with other animals in its ancient environment,” said David Evans, Temerty Chair and Curator of Vertebrate Palaeontology at the Royal Ontario Museum, in a statement.

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It might be time for the megalodon to move over and make room for a new ancient aquatic animal. There’s a newly discovered dinosaur species that may also be pretty good swimmer with duck-like diving abilities.

Natovenator polydontus was a theropod (a hollow-bodied dinosaur) that had three toes and claws on each limb. It lived about 145 to 66 million years ago in Mongolia, during the Upper Cretaceous period. Its recent discovery was outlined in a study published last week in the journal Communications Biology. The name Natovenator polydontus means “many-toothed swimming hunter.”

[Related: Were dinosaurs warm-blooded or cold-blooded? Maybe both.]

One of the similarities that Natovenator has with modern, diving birds is it’s streamlined ribs.

“Whereas diving birds are well known to have streamlined bodies, such body shapes have not been documented in non-avian dinosaurs,” wrote the authors in the study. “Its body shape suggests that Natovenator was a potentially capable swimming predator, and the streamlined body evolved independently in separate lineages of theropod dinosaurs.”

The specimen that the team from Seoul National University, the University of Alberta, and the Mongolian Academy of Sciences examined in this study is similar to Halszkaraptor, another dinosaur that was discovered in Mongolia. Scientists believe Halszkaraptor was likely semiaquatic, but the Natovenator specimen in the study is more complete than one of the Halszkaraptor. This makes it easier for scientists to see Natovenator’s streamlined body shape.

Natovenator is a cousin of the famous Velociraptor, but has a much more streamlined look, with its long jaws and tiny teeth. The specimen was discovered at a spot in the Gobi Desert called Hermiin Tsav or (Khermen Tsav), which is a hot spot for preserving multiple dinosaur species.

David Hone, a paleontologist and professor at Queen Mary University of London, told CNN that it is difficult to say exactly where the new species falls on the spectrum of totally land-dwelling animals to totally aquatic animals. However, the specimen’s arms, “look like they’d be quite good for moving water,” he said. Hone participated in the peer review for this study.

[Related: Spinosaurus bones hint that the spiny dinosaurs enjoyed water sports.]

According to Hone, the next steps to understand Natovenator’s motion should be modeling of the dinosaur’s body shape to help scientists understand exactly how it might have moved. “Is it paddling with its feet, a bit of a doggy-paddle? How fast could it go?”

Additional research should also look back at the environment in which Natovenator lived. “There is a real question of, OK, you’ve got a swimming dinosaur in the desert, what’s it swimming in?” Hone said. “Finding the fossil record of those lakes is gonna be tough, but sooner or later, we might well find one. And when we do, we might well find a lot more of these things.”

In addition to biomechanical studies that will test how Natovenator and related water-dwelling species moved around, studies of geochemical clues in the dinosaur’s teeth and bones, will either confirm or challenge the idea that Natovenator was as strong a swimmer as the study suggests.

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A new fossil find in the United Kingdom is a victory for de-cluttering and organization enthusiasts everywhere.

The fossil specimen of an ancestor of present day lizards first unearthed in the 1950s was recently found stored in a cupboard at the Natural History Museum in London. The discovery potentially shows that today’s lizards likely originated in the Late Triassic period (about 200 million years ago) and not during the Middle Jurassic as previously believed.

[Related: A Scottish fossil is helping scientists fill the gaps in the lizard family tree.]

The findings are described in a paper published today in the journal Science Advances. The team named their discovery Cryptovaranoides microlanius, which means meaning “small butcher,” as a tribute to the animal’s jaws filled with sharp-edged slicing teeth.

“I first spotted the specimen in a cupboard full of Clevosaurus fossils in the storerooms of the Natural History Museum in London where I am a Scientific Associate,” said David Whiteside, from the University of Bristol’s School of Earth Sciences and a co-author of the paper, in a statement. “This was a common enough fossil reptile, a close relative of the New Zealand Tuatara that is the only survivor of the group, the Rhynchocephalia, that split from the squamates over 240 million years ago.

The specimens were originally unearthed from a quarry in southwest England.

“Our specimen was simply labelled ‘Clevosaurus and one other reptile.’ As we continued to investigate the specimen, we became more and more convinced that it was actually more closely related to modern day lizards than the Tuatara group,” Whiteside added. “We made X-ray scans of the fossils at the University, and this enabled us to reconstruct the fossil in three dimensions, and to see all the tiny bones that were hidden inside the rock.”

The age of the new fossil impacts the general estimates of when Squamata, the order of reptiles that includes lizards and snakes, evolved, how quickly they evolved, and even what triggered the general origin of the order.

The study shows that Cryptovaranoides is clearly a squamate due to multiple features including its braincase (which encloses the brain), neck vertebrate, upper median tooth in front of the mouth, and the way that the teeth are set on a shelf in the jaws. It also has features seen in more primitive squamates, including an opening on one side of the end of the upper arm bone (the humerus) where a nerve and an artery pass through and few rows of teeth on the bones making up the roof of the lizard’s mouth.

[Related: These tiny ‘dragons’ flew through the trees of Madagascar 200 million years ago.]

“In terms of significance, our fossil shifts the origin and diversification of squamates back from the Middle Jurassic to the Late Triassic,” says co-author Mike Benton a palentologist also from the University of Bristol, in a statement. “This was a time of major restructuring of ecosystems on land, with origins of new plant groups, especially modern-type conifers, as well as new kinds of insects, and some of the first of modern groups such as turtles, crocodilians, dinosaurs, and mammals.

Adding in older modern squamates help complete this evolutionary picture as the Earth rebuilt after the end-Permian mass extinction, which killed about 95 percent of the Earth’s marine species and 70 percent of land species about 252 million years ago.

“The name of the new animal, Cryptovaranoides microlanius, reflects the hidden nature of the beast in a drawer but also in its likely lifestyle, living in cracks in the limestone on small islands that existed around Bristol at the time,” Sofia Chambi-Trowell, co-author and PhD research student at the University of Bristol said in a statement.

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It looks like Tyrannosaurus rex has another relative to add to its ever-growing family tree. In 2017, Badlands Dinosaur Museum crew member Jack Wilson spotted the remains of what turned out to be a new species of tyrannosaur, named Daspletosaurus wilsoni, or D. wilsoni. Wilson first saw a small, flat piece of bone projecting out of the bottom of a cliff at the Judith River Formation in northeastern Montana. The fossil Wilson spotted turned out to be part of the dinosaur’s nostril.

Additional fossils were uncovered between 2017 and 2021, including skeletal fragments of a rib and toe bone and parts of a fossilized skull. Those bits were enough to determine this was a new species, as detailed in a paper published on November 25 in the journal Paleontology and Evolutionary Science. The remains date back to 76.5 million years ago, during the Cretaceous period, millions of years before T. rex stomped through the Late Cretaceous.

[Related: Is T. rex really three royal species? Paleontologists cast doubt over new claims.]

One of D. wilsoni‘s unique features is an arrangement of spiked hornlets around its eyes. It also has a mix of attributes that were found in more primitive types of tyrannosaurs, such as prominent set of horns around the eye. It also boasts physical features more common in later members of this group, including the famed T. rex. One of these more advanced tyrannosaur features is a tall eye socket and expanded air-pockets inside of the skull.

“In this way, D. wilsoni is a ‘halfway point’ or  ‘missing link’ between older and younger tyrannosaur species,” wrote study authors Elías Warshaw, a paleontology student at Montana State University and Denver Fowler, a paleontologist and curator of Badlands Dinosaur Museum, in a statement.

The Tyrannosaur family is large: It has nine genera, which falls above species and below family in the system that classifies animal and plants. The family includes a genus of predators called daspletosaurs, which lived about 79.5 million and 74 million years ago, during the Late Cretaceous Period. The team believes that D. wilsoni is an intermediate daspletosaur, the descendant of Daspletosaurus torosus, and the predecessor of Daspletosaurus horneri. Daspletosaurus is Greek for “frightful lizard,” and the specimen was nicknamed Sisyphus, in reference to the myth of the man cursed to push a boulder up a hill for eternity. It took an enormous amount of effort to extract the bones from the surrounding rock, including removing about 25 feet of stone from the top of the skeleton.

In North America during the Late Cretaceous, multiple closely related species made up the evolutionary families of dinosaurs. It was previously thought that these species lived at the same time, which would be evidence of what biologists call branching evolution.  However, newly discovered specimens such as this one and a better understanding of when the animals lived has changed how paleontologists understand dinosaur evolution.

[Related: The T. rex ‘dynasty’ reigned for more than 125,000 generations.]

“We can now see that many of these species are actually very finely separated in time from each other, forming consecutive ladder-like steps in a single evolutionary lineage where one ancestral species evolves directly into a descendant species,” wrote Warshaw and Fowler.

This process is called anagenesis, or linear evolution. It is different from cladogenesis evolution, where successive branching events create many closely related species that that look similar but are evolutionary “cousins,” not descendants and ancestors.

“The new study supports the addition of tyrannosaurs to a growing list of dinosaurs (including horned and duckbilled dinosaurs) for which anagenesis (linear evolution) has been proposed,” said Warshaw and Fowler. This suggests that linear evolution may be more widespread in dinosaurs and that branching evolution occurs less frequently than previously thought.

Warshaw is currently conducting more detailed research into the link between T. rex and Daspletosaurus.

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While lizards and dinosaurs trotted the Earth together, lizards were the one of the newer animals on the block during the Middle Jurassic period. Scientists are still unraveling their unique history. Now, roughly 166 million years later, a nearly-complete fossil of a lizard skeleton is helping scientists fill in some of those evolutionary gaps.

The specimen was discovered on Scotland’s Isle of Skye and is called Bellairsia gracilis. Bellairsia was a tiny lizard ancestor and was only about two inches long. The “exceptional” new fossil is described in a study published this week in Nature. The fossil is only missing its snout and tail and is likely the most complete fossil lizard of this age anywhere in the world.

[Related: This 6-inch-long Jurassic creature does a great lizard impersonation.]

Within Bellairsia‘s skeleton are a mixture of older ancestral features and modern features, which provides evidence of what the ancient ancestor of present-day lizards might have looked like. “This little fossil lets us see evolution in action,” said first author Mateusz Tałanda from the University of Warsaw and University College London, in a statement. “In paleontology you rarely have the opportunity to work with such complete, well-preserved fossils coming from a time about which we know so little.”

A team led by Oxford University and the National Museums Scotland first found the fossil in 2016. In addition to its beautiful scenery, the Isle of Skye is a hot spot for fossils (including ones from extinct amphibians and mammals) that is giving scientists a window into how present-day animal groups evolved through time.

“Bellairsia has some modern lizard features, like traits related to cranial kinesis–that’s the movement of the skull bones in relation to one another. This is an important functional feature of many living squamates,” Tałanda said.

Squamates are a huge present-day animal group that includes lizards, snakes, chameleons, and geckos. With more than 10,000 species of squamates living today, they are one of the most species-rich living vertebrate animal groups. The smallest living squamate is the Virgin Islands Dwarf Sphaerodactylus, coming in at only about an inch long and less than one-tenth of an ounce. The Komodo Dragon is the largest living squamate, which has been known to reach about 10 feet long and weigh over 350 pounds.

[Related: This pterosaur ancestor was a tiny, flightless dog-like dinosaur.]

Elsa Panciroli from the Oxford University Museum of Natural History and National Museums Scotland is one of the study’s co-authors and also was the lucky scientist to first discover the fossil. “It was one of the first fossils I found when I began working on Skye,” Panciroli said in a statement. “The little black skull was poking out from the pale limestone, but it was so small I was lucky to spot it. Looking closer I saw the tiny teeth, and realized I’d found something important, but we had no idea until later that almost the whole skeleton was in there.”

While scientists know that the earliest origins of squamates lie about 240 million years ago during the Triassic period, a lack of fossils from both the the Triassic and Jurassic period has made their early evolution and anatomy difficult to trace. Analyzing the new fossil alongside some living and extinct squamates shows that Bellairsia belongs to the “stem” of the squamate family tree. It likely split from other lizards just before modern groups of lizards arose. It also supports the idea that geckos branched out early and that Oculudentavis is actually a stem on the squamate family tree and not a dinosaur.

“Fossils like this Bellairsia specimen have huge value in filling gaps in our understanding of evolution and the history of life on Earth,” said co-author Roger Benson from the University of Oxford, in a statement. “It used to be almost impossible to study such tiny fossils like this, but this study shows the power of new techniques including CT scanning to image these non-destructively and in great detail.”

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In case a tarantula nebula and a skeleton galaxy weren’t enough spookiness for one Halloween, scientists are learning more about dinosaur mummies. About 67 million years ago, a duck billed dinosaur called Edmontosaurus was going about its business in what is now North Dakota. The reptile died, but that wasn’t the end of Edmontosaurus’ troubles. A hungry ancient relative of the crocodile snuck in and started to munch on Edmontosaurus’ body, marking up its bones along the way. This hungry croc wasn’t good at destroying the evidence of its lunch, as the fossilized remains of Edmontosaurus’ skin contain well-preserved bite marks.

While this isn’t the fist dinosaur mummy to be discovered, they are a historically rare find. Typically, fossilized skin forms when the carcass of a dinosaur was protected from becoming a predator’s snack due to a quick burial and/or desiccation. Desiccation is when the moisture is sucked out of the skin of a living organism and deflated is when it shrinks down.

Dinosaur “mummies” have well preserved skin like those of this Edmontosaurus, but this specimen was different because of its crocodile wounds. The bite marks left behind from a posthumous but pre-mummy attack can help scientists uncover more about how this skin is so well preserved even after millions of years. In a new study published in the journal PLOS One, researchers looked at both fossil evidence and modern animal carcasses to propose a new explanation for how prehistoric dinosaur mummies might form. Based on this new explanation, the study suggests that there may even be more dino mummies out there just waiting to be found.

[Related: Feast your eyes on exquisite fossils from an ancient rainforest (and more).]

For the study, Stephanie Drumheller, a palentologist from the University of Tennessee, Knoxville, and colleagues looked at the Edmontosaurus fossil, aptly nicknamed “Dakota,” from the North Dakota Heritage Center and State Museum. Dakota was discovered in 1999 and excavated from the famed Hell Creek Formation, a geological formation shaped roughly 145 million to 66 million years ago near the end of the Cretaceous period and the start of the Paleogene period. Dakota had large patches of dry and seemingly deflated skin on its limbs and tail. The unhealed skin damage from its encounter with ancient crocodiles provides evidence that it became a mummy even though it wasn’t protected from scavengers.

Scavengers, like modern-day vultures, typically go after internal tissues and organs, which leaves behind the skin and bones. The bites to remove the organs helps gasses and liquids escape, helping the skin and bones dry out. The authors of study believe that skin damage from an incomplete scavenging would have exposed the dinosaurs insides, drying out the skin as the remains were buried.

[Related: This whale fossil could reveal evidence of a 15-million-year-old megalodon attack.]

“Not only has Dakota taught us that durable soft tissues like skin can be preserved on partially scavenged carcasses, but these soft tissues can also provide a unique source of information about the other animals that interacted with a carcass after death,” Clint Boyd, senior paleontologist at the North Dakota Geological Survey, said in a press release.

Desiccation and deflation is common with present day carcasses and explains how dinosaur mummies might actually be able to form. But just as every living being is a little different, every death is a little different—and the team suggests that there are possibly many ways for a dinosaurs to become a mummy. Understanding how dino mummification works will guide how paleontologists carefully collect and interpret the remains of even more varieties of long-lost creatures.

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Pterosaurs are some of the stars of the latest chapters of Jurassic Park franchise and the cinematic television streaming series Prehistoric Planet. These giant winged dinosaurs scoured the skies from the late Triassic Period all the way up to the demise of the dinosaurs in the late Cretaceous Period, but they weren’t always so large. Some new clues are revealing just how tiny the ancestors of these winged reptiles once were.

In a study out today in the journal Nature, an international group of scientists discuss their new examination of a Triassic-era fossil that was first discovered 100 years ago in Scotland. Computed Tomography (CT scanning) helped create the first accurate and whole skeleton reconstruction of the non-avian Scleromochlus taylori, revealing physical features that show that it’s a close pterosaur relative. The specimen is within a group known as Pterosauromorpha, an extinct group of reptiles called lagerpetids (which means “rabbit-reptiles”) that are grouped together with the pterosaurs.

[Related: The biggest animal ever to fly was a reptile with a giraffe-like neck.]

“Pterosaurs were the first vertebrates to evolve powered flight and for nearly two centuries, we did not know their closest relatives,” Sterling Nesbitt, a paleontologist and professor from Virgina Tech University, said in a press release. “Now we can start filling in their evolutionary history with the discovery of tiny close relatives that enhance our knowledge about how they lived and where they came from.”

Lagerpetids lived about 240 to 210 million years ago and they were relatively small, even by modern mammal standards. They were generally about the size of a cat or small dog. Schleromochlus was even smaller, at under 7 inches (20 centimeters) in length, a little more than half the size of a standard school ruler. The results of this study support the general hypothesis that the first flying reptiles evolved from small, bipedal ancestors like Schleromochlus.

These findings also settle a 100 year-long debate: Scientists have long disagreed as to whether Scleromochlus were an evolutionary step in the direction of pterosaurs, dinosaurs, or else some other reptile entirely.

[Related: Zimbabwe’s newest dinosaur may be Africa’s oldest.]

“It’s exciting to be able to resolve a debate that’s been going on for over a century, but it is far more amazing to be able to see and understand an animal which lived 230 million years ago and its relationship with the first animals ever to have flown,” said Davide Foffa, a research associate at National Museums Scotland, and a research fellow at the University of Birmingham, in a press release. “This is another discovery which highlights Scotland’s important place in the global fossil record, and also the importance of museum collections that preserve such specimens, allowing us to use new techniques and technologies to continue to learn from them long after their discovery.”

The fossil of Scleromochlus has been difficult to study in depth due to its size and because it is poorly preserved in a block of sandstone. The specimen is part of the Elgin reptiles, a group of Triassic and Permian fossils that were found in the Lossiemouth Sandstone Formation near the town of Elgin in the Morayshire region of northeast Scotland.

“The Elgin reptiles aren’t preserved as the pristine, complete skeletons that we often see in museum displays,” said Paul Barrett, a professor and paleobiologist at the Natural History Museum, in a press release. “They’re mainly represented by natural moulds of their bone in sandstone and—until fairly recently—the only way to study them was to use wax or latex to fill these moulds and make casts of the bones that once occupied them. However, the use of CT scanning has revolutionized the study of these difficult specimens and has enabled us to produce far more detailed, accurate and useful reconstructions of these animals from our deep past.”

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Just off of the western coast of Mexico’s Yucatán peninsula lies the 12 mile deep, 6.2 mile wide Chicxulub crater. The 66 million year-old impact crater is the site where a massive asteroid struck the Earth, wiping out the dinosaurs and about three quarters of all life on Earth. But new evidence shows that it was even more destructive than previously realized.

A study published today in the journal AGU Advances shows that the asteroid also triggered a monstrous tsunami with mile-high waves that scoured the ocean floor thousands of miles from the impact site in Mexico. A team of researchers built the a first global simulation of the Chicxulub impact tsunami to be published in a peer-reviewed journal and reviewed the geological record at over 100 sites around the world to determine the tsunami’s path and power.

“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” lead author Molly Range, who conducted the modeling study for a master’s thesis at the University of Michigan, said in a press release.

[Related: If that asteroid had been 30 seconds late, dinosaurs might rule the world and humans probably wouldn’t exist.]

The team estimates that the initial energy in the Chicxulub impact tsunami was up to 30,000 times larger than the energy of the 2004 Indian Ocean earthquake tsunami—a devastating disaster killed more than 230,000 people and was one of the largest tsunamis in the modern record.

To determine just how powerful the tsunami was, the team analyzed the published records of 165 marine boundary sections, or marine sediments in the geologic record deposited around the time the asteroid struck the earth, and sediment cores. The cores act as a terrestrial timeline that scientists can use to analyze the layers or rock, sand, and ice to better understand what the Earth was like millions of years ago.

The K–Pg boundary (also called the K-T boundary) marks around the time where the astroid hits—ending the Cretaceous Period. Through the sediment in these boundary sections, they found that the impact tsunami radiated mainly to the east and northeast (into the North Atlantic Ocean), then later to the southwest through the Central American Seaway which used to separate the continents of North America and South America. Lastly, the tsunami diffused into the South Pacific Ocean.

“The distribution of the erosion and hiatuses that we observed in the uppermost Cretaceous marine sediments are consistent with our model results, which gives us more confidence in the model predictions,” said Range.

The authors also used the boundary section sediment to determine the speed of underwater currents in those basins. In some nearby spots, the current was likely 0.4 miles per hour (20 centimeters per second), a velocity that is strong enough to erode fine-grained sediments on the seafloor. By comparison, the South Atlantic, the North Pacific, the Indian Ocean, and the region that is today the Mediterranean appear to have been largely protected from the strongest effects of the tsunami.

Outcrops of the K-Pg boundary were found on the eastern shores of New Zealand’s north and south islands, over 7,500 miles (12,000 km) from the crater impact site. “We feel these deposits are recording the effects of the impact tsunami, and this is perhaps the most telling confirmation of the global significance of this event,” Range said.

[Related: It was probably springtime when an asteroid did the dinosaurs in.]

To create the computer model of the mass extinction event, a large computer program called a hydrocode simulated the chaotic first 10 minutes of the extinction event. The asteroid in the simulation was modeled after previous studies that found the dinosaur-killing space rock to be 8.7 miles in diameter and moving at 27,000 mph After it struck the Earth’s crust under shallow ocean waters, a 62 mile (100 km) wide crater ejected dense clouds of dust and soot into the atmosphere.

According to the simulation, ejected material formed a 2.8 mile (4.5 km) high wave two and a half minutes after impact which then subsided when the material fell back to Earth. Ten minutes after the projectile hit the Yucatan, a 0.93 mile (1.5 km) high tsunami wave began rolling across the ocean in all directions.

This 10-minute simulation was entered into two tsunami-propagation models (called MOM6 and MOST) used by the National Oceanic and Atmospheric Administration (NOAA) to track and understand these enormous waves. “The big result here is that two global models with differing formulations gave almost identical results, and the geologic data on complete and incomplete sections are consistent with those results,” University of Michigan paleoceanographer and study co-author Ted Moore said in a press release. “The models and the verification data match nicely.”

The simulation mirrored geologic findings, showing that about one hour after impact, the wave had spread outside the Gulf of Mexico and into the North Atlantic. Four hours after impact, the tsunami passed through the Central American Seaway and into the Pacific, and by the end of day one, the waves had crossed most of the Pacific Ocean and entered the Indian Ocean from both sides. By 48 hours after impact, significant tsunami waves had reached most of the coastlines on Earth.

“Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent,” the authors said. “Any historically documented tsunamis pale in comparison with such global impact.”

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About 150 million years ago, Opisthiamimus gregori crawled around Jurassic-era North America, searching for food alongside more famous dinosaurs like Stegosaurus and Allosaurus. It munched on insects and small invertebrates, and, at six inches long, was small enough to fit inside the palm of a modern adult’s hand.

This extinct species belongs to the same ancient lineage as the present-day tuatara reptile, according to new findings from Smithsonian National Museum of Natural History, University College in London, and the London Natural History Museum. Their study, published on September 15 the Journal of Systematic Paleontology, helps explain some of the unique differences between this extinct creature in the New Zealand critter.

O. gregori is a rhynchocephalian, a distinct group that diverged from lizards during the Triassic Period. The tuatara (its only living relative) is exclusively found in present-day New Zealand, looks a little bit like a stout iguana, and is a bit of an enigma: It looks like a lizard, but isn’t a lizard. Lizards belong to an order of reptiles called sqamates, which also includes snakes and worms).

[Related: These lizards use built-in ‘scuba gear’ to breathe underwater.]

“What’s important about the tuatara is that it represents this enormous evolutionary story that we are lucky enough to catch in what is likely its closing act,” said Matthew Carrano, the National Museum of Natural History’s curator of Dinosauria, in a press release. “Even though it looks like a relatively simple lizard, it embodies an entire evolutionary epic going back more than 200 million years.”

A complete and well-preserved O. gregori skeleton was found in northern Wyoming’s Morrison Formation, sitting atop was what once an Allosaurus nest. During the Jurassic period, rhynchocephalians could be found all over the world, came in all sorts of shapes and sizes, and were everything from aquatic fish hunters to bulky plant munchers. It is not still understood why, rhynchocephalians all-but disappeared, while snakes and lizards grew to be the more common and diverse reptiles across the globe.

More study of these specimens could reveal why just New Zealand’s tuatara is surviving today. “These animals may have disappeared partly because of competition from lizards but perhaps also due to global shifts in climate and changing habitats,” Carrano said. “It’s fascinating when you have the dominance of one group giving way to another group over evolutionary time, and we still need more evidence to explain exactly what happened, but fossils like this one are how we will put it together.”

[Related: Feast your eyes on exquisite fossils from an ancient rainforest (and more).]

This fossil is almost entirely complete, and is only missing the tail and parts of the hind legs. According to Carrano, such a complete skeleton is rare for small prehistoric creatures like this because, “their frail bones were often destroyed either before they fossilized or as they emerge from an eroding rock formation in the present day.” Paleontologists typically identify Rhynchocephalians from small fragments of their jaws and teeth.

The team used CT scans to capture everything they possibly could about the fossil and created a nearly complete 3D reconstruction of the animal. The 3D skull is of particular interest.

“Such a complete specimen has huge potential for making comparisons with fossils collected in the future and for identifying or reclassifying specimens already sitting in a museum drawer somewhere,” said research associate, David DeMar Jr., in a press release. “With the 3D models we have, at some point we could also do studies that use software to look at this critter’s jaw mechanics.”

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About 15 million years before the blockbuster hit “Jaws” snapped up the attention of generations of movie goers, the mightly megalodon (Otodus megalodon) stalked the Earth’s oceans. The ancestor of modern-day sharks could eat prey the size of an orca whale in only about five bites. The largest specimens reached between 58 and 72 feet long and had teeth that are almost three times the size of a modern-day great white.

Now, a team of researchers in southern Maryland have unearthed fossil evidence of a possible bottoms-up megalodon attack on a whale. The fossils were found close together in southern Maryland’s Calvert Cliffs, by Mike Ellwood, a Calvert Marine Museum volunteer and fossil collector. They date back to the Miocene Epoch (about 23 million to 5.3 million years ago), when Maryland was covered in a warm and shallow coastal sea with big plumes of sea algae and succulent aquatic plants that supported turtles, crustaceans, and marine mammals.

In an interview with Live Science, Stephen J. Godfrey, a curator of paleontology at the Calvert Marine Museum in Solomons, Maryland and lead author of the study said “in terms of the fossils we’ve seen on Calvert Cliffs, this kind of injury is exceedingly rare. The injury was so nasty, so clearly the result of serious trauma, that I wanted to know the backstory.”

[Related: 3D models show the megalodon was faster, fiercer than we ever thought.]

The study, published last month in the journal Palaeontologia Electronica, details their examination of two fossils from the whale’s fractured vertebrae and one megalodon tooth. They used CT scans and other medical imaging techniques at a local hospital to get a closer look inside the ancient remains.

One of the vertebrae shows evidence of a compression fracture. The study proposes that the whale’s backbone must have been forcefully bent into such a tight curve, that pressure from the vertebra right next to it smashed into one another to sustain this kind of injury.

“We only have circumstantial evidence, but it’s damning circumstantial evidence,” Godfrey told Live Science. “This is how we see the story unfolding. Although there are limitations to what we can claim, and we want the evidence to speak for itself.”

Another possible cause of this kind of injury to the backbone could be that the whale ingested a toxic algae that caused it convulse so violently that it broke its own back. The authors, however, argue that a megalodon attack is the most likely cause due to the magnitude of the injury to the spinal column bones.

The team also examined a megalodon tooth that was uncovered alongside vertebrae fossil. The tip of the tooth broke off, which could occur after it struck something hard like a bone. It also could have fallen out while swimming or feeding on an already dead or injured whale’s remains. But the team isn’t ruling out the possibility that a megalodon lost its tooth while ramming its jaws into a whale.

[Related: Megalodons liked to snack on sperm whale snouts.]

The teeth of extinct sharks are a common discovery in Calvert County Maryland and they come from a wide variety of shark species, according to the Maryland Geological Survey. Citizen scientists and paleontologists alike have uncovered teeth from Galeocerdo contortus and Galeocerdo triqueter (similar to modern day tiger sharks), Sphyrma prisca (a relative of the hammer head shark), and Odontaspis elegans (the Sand Shark). It’s thought that this area was a whale and dolphin calving ground, which potentially made the smaller whales easier targets for hungry megalodons.

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Late Permian Period reptile Coelurosauravus elivensis (C. elivensis) won’t be laying colorful scaly eggs or burning down armies anytime soon, but it does have the title of the planet’s first flying reptile.

In a new study published in Journal of Vertebrate Paleontology, researchers believe that the four-inch-long winged reptile evolved to glide between tree tops. C. elivensis was a tetrapod that lived during between 252 million to 260 million years ago in present-day Madagascar, and used a patagium (thin membranes extending from its torso to the front limbs) as a make shift pair of wings to travel above the tree canopy.

These unique features have earned the tiny lizard the title of “world’s first gliding reptile,” according to researchers from the French National Museum of Natural History in Paris and the Staatliches Museum für Naturkunde Karlsruhe in Karlsruhe, Germany. The first fossils of C. elivensis were unearthed in 1907 and sparked a spirited debate over how the reptile actually lived and how it evolved to have these wings. The team on this study created a near-perfect skeletal reconstruction of C. elivensis and the new research advanced knowledge of the tetrapod’s form and its habits. The team says that clues in the tree canopy of this extinct ecosystem have helped solve the puzzle.

[Related: Could dragons be real? Not in the way we think.]

A tree canopy of overlapping tree tops allowed the reptiles to move about without risking an altercation with predators on the ground.

“These dragons weren’t forged in mythological fire—they simply needed to get from place to place. As it turned out, gliding was the most efficient mode of transport and here, in this new study, we see how their morphology enabled this,” said lead author Valentin Buffa, from the Centre de Recherche en Paléontologie – Paris at the French Natural History Museum, in a press release.

The team looks at three known C. elivensis fossils and related specimens belonging to the Weigeltisauridae family of gliding Permian reptiles found present-day Germany. They focused on the postcranial portion (head skeleton), body, torso, limbs, and its “remarkable gliding apparatus,” called the patagium. The patagium is somewhat like a bat’s wing and is found in flying squirrels, sugar gliders, and colugos aka “flying lemurs.”

[Related: These flying squirrels fluoresce hot pink, and no one knows exactly why.]

Researchers were uncertain about the exact placement of the patagails (who together form the patagium) on C. elivensis‘ body and the study proposes that winglike structures were most likely located low on the trunk and extending from the dermal bones located between the sternum and pelvis or from the trunk’s musculature. This determination is based on the position of the bones, since none of the specimens contained any preserved soft tissues.

The team also compared this new location of these patagium to those of Draco. Draco (the Latin word for dragon) is a genus of modern-day gliding lizards often called “flying dragons.” These lizards predominantly live in Southeast Asia’s rainforests. The scientists reported that C. elivensis gliding apparatus was lower on its abdomen when compared to modern gliding lizards according to the statement and added that Draco’s patagials are supported by its long and flexible ribs.

“C. elivensis does bear a striking resemblance to the contemporary genus Draco,” Buffa said. “While its habits were likely similar to those of its modern counterpart, we do see subtle differences though. Like Draco lizards, Coelurosauravus was able to grasp its patagium with its front claws, stabilize it during flight, and even adjust it, allowing for greater maneuverability. An additional joint in one finger, though, may have enhanced this capability. This may have been a necessary compensation for the lower positioning of the patagium, which likely made it more unstable.”

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When looking at a map, the continents of South America and Africa look like they sort of fit together like puzzle pieces. This geographic symmetry is because the continents, and most of the land on Earth, were once fused together in a giant land mass called Pangea from about 200-300 million years ago. This ancient supercontinent influenced life on Earth during the Paleozoic and late Triassic periods. About 230 million years later, scientists have discovered Africa’s oldest dinosaur to date on the continent in Zimbabwe—and the nearly complete skeleton is now helping scientists better understand dinosaur evolution.

A nearly complete skeleton of Mbiresaurus raathi was discovered after five years, COVID-19 related delays, and extremely careful digging. Mbiresaurus lived along the banks of an ancient river in current day Zimbabwe, during the late Triassic period (about 252 million to 201 million years ago). The long-necked ancient lizard is a sauropodomorph, a relative of giant long-necked sauropods like Brachiosaurus and Apatosaurus. They were smaller than their late Jurassic to early Cretaceous counterparts, at about 6 feet long and 1.5 feet tall at the hip. By comparison, a later sauropod called Dreadnoughtus was about 85-feet-long.

According to the researchers, the Mbiresaurus was bipedal (stood on two legs), had a relatively small head, and it’s small, serrated, triangle-shaped teeth, suggesting that it was an herbivore or possibly omnivore.

“When we talk of the evolution of early dinosaurs, fossils from the Triassic age are rare,” said Darlington Munyikwa, the deputy director of National Museums and Monuments of Zimbabwe, who was part of the expeditions, in an interview with the BBC.

[Related: Were dinosaurs warm-blooded or cold-blooded? Maybe both.]

The findings were published yesterday in the journal Nature, and help answer why dinosaur fossils have only been found in some parts of Pangaea. Previously, the oldest known dinosaur specimens (dating back about 230 million years ago) were found in South America (specifically Argentina and Brazil), with a few partial specimens in India.

“The discovery of Mbiresaurus raathi fills in a critical geographic gap in the fossil record of the oldest dinosaurs and shows the power of hypothesis-driven fieldwork for testing predictions about the ancient past,” said primary author Christopher Griffin, who graduated in 2020 with a Ph.D. in geosciences from the Virginia Tech College of Science, in a press release. “These are Africa’s oldest-known definitive dinosaurs, roughly equivalent in age to the oldest dinosaurs found anywhere in the world.”

[Related: Move over, Stegosaurus, there’s a new armored dino in town.]

Griffin (now a postdoc at Yale University) Munyikwa, and Michel Zondo of the Natural History Museum of Zimbabwe in Bulawayo unearthed the nearly complete skeleton in the banks of the Cabora Bassa River Basin. In an interview with Science, Griffin recalled spotting what appeared to be a thigh bone sticking out of the river, “As soon as I dug that out, I knew that I was holding Africa’s oldest dinosaur,” said Griffin. “I had to sit down and breathe for a minute, because I thought, ‘There could be a lot more [bones] in there.’”

The new dinosaur received its name after Mbire, the the district in Zimbabwe where the skeleton was found and also is the name of an historic Shona dynasty that once ruled the region. The name “raathi” is in honor of Michael Raath, a paleontologist who first published the discovery of fossils in northern Zimbabwe.

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Fulfilling the dreams of child paleontologists everywhere, the skeletal remains of a possible sauropod, the group that includes the iconic brachiosaurus genus, have been found in a backyard. The 82-foot-long skeleton was uncovered in Pombal, a city in central Portugal.

In 2017, the property owner noticed some fragments of fossilized bones during a backyard construction project. The owner contacted a research team who investigated the site and launched an excavation campaign. Between August 1 and 10 of this year, Portuguese and Spanish paleontologists working on the site have unearthed what could be the remains of the largest sauropod dinosaur ever found in Europe.

[Related: This fossilized dinosaur embryo is curled up just like a baby bird.]

“It is not usual to find all the ribs of an animal like this, let alone in this position, maintaining their original anatomical position. This mode of preservation is relatively uncommon in the fossil record of dinosaurs, in particular sauropods, from the Portuguese Upper Jurassic”, said Elisabete Malafaia, Postdoctoral researcher at the Faculty of Sciences of the University of Lisbon (Ciências ULisboa), Portugal, in a press release.

Sauropods were long-necked, long-tailed, herbivorous dinosaurs that stood on four legs (or quadrupedal). The smallest sauropods stood at about 50 feet and the largest (Brachiosaurus) standing at an astounding 98 feet tall and weighed over 170,000 pounds.

Researchers have gathered an important set of axial skeleton parts from the site, including vertebrae and ribs of a possible brachiosaurid sauropod dinosaur. The Brachiosauridae group lived during the Upper Jurassic period to the Lower Cretaceous period, about 160 to 100 million years ago. Brachiosauridaes are characterized by their very developed forelimbs. Some of the most notable species in this group of sauropods, are  Brachiosaurus altithorax, Giraffatitan brancai, and Lusotitan atalaiensis (found in western Portugal). A leaf-munching, herd-moving brachiosaurus was also the first dinosaur spotted by famed fictional paleontologist Alan Grant, tenacious fictional paleobotanist Ellie Sattler, and witty fictional chaotician Ian Malcolm in 1993’s Jurassic Park.

[Related: The largest dinosaurs got huge way earlier than we thought.]

The team is now testing a hypothesis that there are more parts of the skeleton that could be uncovered at other deposit sites.

“The research in the Monte Agudo paleontological locality confirms that the region of Pombal has an important fossil record of Late Jurassic vertebrates, which in the last decades has provided the discovery of abundant materials very significant for the knowledge of the continental faunas that inhabited the Iberian Peninsula at about 145 million years ago”, adds Malafaia.

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When Africa and South America split apart during the Jurassic, birthing the Atlantic Ocean, the separation left a plateau of shallow ocean off the west coast of Guinea. “All the sediments are very flat, almost like a layer cake,” says Uisdean Nicholson, a marine geologist at Heriot-Watt University in Scotland who studies the region to learn about the birth of the Atlantic.

So in 2017, when Nicholson was examining seismic scans of the region taken by oil and gas exploration vessels, an unexpected feature jumped out: a 5-mile-wide dimple buried deep in the cake.

A closer analysis of the site, led by Nicholson and published today in the journal Science Advances, argues that it’s the crater from a meteor as wide as the Eiffel Tower is tall. If it’s confirmed as a crater, it would have crashed into Earth within a million years of the Chicxulub meteor that caused the extinction of the dinosaurs.

Nicholson hunted for other ways to explain the dimple—escaping methane bubbles, tectonic activity, or a volcano. But none of them quite explained the crater’s size, location, and shape.  So he turned to cosmic impact experts for help. “Probably every week, somebody sends me circles they spotted on Google Earth, or in seismic data,” says Sean Gulick, an expert in meteor strikes at the University of Texas Institute for Geophysics, and a coauthor on the research. But the dimple, which the team calls the Nadir Crater, passed the tests they threw at it. “Shapes, sizes, even modeling, it’s all fitting,” says Gulick.

To further confirm the explanation, Veronica Bray, a planetary scientist at the Lunar and Planetary Laboratory in Tucson and a member of the team, simulated multiple meteor strikes in different ocean depths. A rock longer than 1,000 feet across, striking the half-mile-deep ocean, created a close approximation to the actual crater. According to the simulation, in the first few seconds after the impact, the rock would have plunged nearly a mile into the ocean floor, vaporizing rocks and water, and sending a tsunami in all directions. 

The vibrations from the impact would be so intense that “the rocks or sediment below the seabed become a fluid,” Nicholson says. The rock around the crater would shatter, and “you get this massive vertical column, like you dropped something into a puddle,” he says. “That happens with the water, but it also happens with the rocks below”—leaving a crater with an uplifted mound of solid rock in the middle, like what’s buried under the Guinean seafloor.

“The energies involved in this are enormous,” says Gulick. “This is 1000 times the energy of the Tonga eruption. It would generate earthquakes that are magnitude 7.5 or 8.”

Ludovic Ferrière, an impact crater expert from the Natural History Museum Vienna who was not involved in the work, agrees that the shape of the feature is interesting and warrants further investigation—but he’s skeptical of the decision to publish on the basis of seismic images alone. “It’s a very nice proposal,” he says. “”But it’s too preliminary. At the end they may be right, but they may be completely wrong.”

[Related: This small asteroid has a tiny moon of its own]

Ferrière—who says that he discussed the crater with Gulick at a bar days before the publication—says that he has found similarly compelling craters.  But, without physical evidence, he doesn’t think they pass scientific scrutiny to publish. “To find the killer in a murder, you need DNA or blood,” he says. The same is true for an impact crater: The only hard evidence of a meteor are the presence of “shocked” minerals that form only under the hammer blow of a cosmic strike, or actual spray from the extraterrestrial object.

Drilling from a ship hundreds of feet into the seafloor itself is the only way to be sure. Yet this creates a chicken-egg problem. The International Ocean Discovery Program, the academic institution best equipped to take a sample—“at a cost of several million dollars,” Nicholson writes over email–would do so only after a peer-reviewed paper confirms that it is a good candidate. 

The International Ocean Discovery Program’s ship, which can collect core samples under thousands of feet of water and hundreds more feet of rock, will visit the region in 2023. The team has submitted an application for time with the drill, and hopes to analyze samples from the crater in the next few years. 

That drilling will also clarify the age of the proposed crater. Based on cores drilled a little over 100 miles from the proposed crater, the site sits right around the K-PG boundary, the line that marks the mass extinction of dinosaurs, pterosaurs, and giant marine reptiles, 65 million years ago. That die-off was caused when the miles-wide Chicxulub meteor smashed into what’s now the Yucatan Peninsula.

[Related: It was probably springtime when an asteroid did the dinosaurs in]

But the sound waves the team is relying on in Guinea produce a slightly fuzzy image, which can’t firmly pin down the date. “To the best of our knowledge, we’re at the boundary, but it could be, could be a million years older or younger,” says Nicholson.

If the crater sits right at the boundary, it’s possible that it was caused by a fragment of the Chixculub meteor that broke off on a previous fly-by past Earth, though Gulick thinks this is unlikely. Alternatively, it could have been  part of an asteroid swarm that intercepted our planet over the course of thousands of years. Ferrière, for his part, calls these hypotheses “speculation upon speculation”—without confirmation that the Nadir Crater is actually a crater, he says, “it’s like constructing a big castle of stone on something that is not stable.”

A similarly sized meteor hits Earth roughly every 700,000 years, so even if it’s a crater, it’s  not necessarily connected to the Chicxulub impact. But Gulick says that documented craters are so rare–there are just over 200 confirmed or likely craters on Earth—that to find one within a million years of Chicxulub would be a surprise.

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About 23 to 3.6 million years ago, a shark roughly three times the size of the great white shark (Carcharodon carcharias)—arguably made famous in the blockbuster 1975 movie JAWS—roamed the oceans of the world. The megalodon (Otodus megalodon or O.megalodon) is believed to be the largest shark that ever has lived, measuring 34 to 66 feet and weighed upwards of 100,000 pounds. That’s about the weight of a train car.

New research published this week in the journal Science Advances suggests that the sizable shark was not only the apex predator of its day, but a “transoceanic super-predator” that could travel thousands of miles across oceans on long migrations, even faster than modern-day sharks. The research by Swansea University PhD student Jack Cooper, shark expert Catalina Pimiento from the Paleontological Institute and Museum at the University of Zurich, and John Hutchinson from the Royal Veterinary College shows the sharks may have eaten meals that were the size of an orca whale, consumed in an about five or more bites.

The researchers used data from an O. megoladon fossil vertebral column, various teeth, and a chondrocranium from our friend the great white shark (its closest living relative) to build out the 3D model.

“The 3D modeling of O.megalodon was only possible thanks to a rare and exceptional vertebral column specimen from Belgium: 141 vertebrae from a single shark,” said Cooper, in an e-mail to Popular Science. “It’s a one of a kind specimen that may well hold the key to further discoveries on this giant shark, having mostly been in museum storage in Brussels since the 1860s.”

Professor Hutchinson added, “Computer modeling provides us with an unprecedented ability to use exceptionally well-preserved fossils to reconstruct the entire body of extinct animals, which in turn allows estimations of biological traits from the resulting geometry. Models of this nature represent a leap in knowledge of extinct super predators such as megalodon and can then be used as a basis for future reconstruction and further research.”

The 3D model allowed the team to figure out the shark’s length, volume, and gape size. These measurements, in turn, helped them calculate its body mass, inferring swimming speed, energetic demands, and stomach volume based on the relationship between these variables and body mass in living sharks. The newly calculated swimming speed means that the shark was potentially able to swim further distances than its competitors, increasing how quickly it could migrate and eat its way around the ocean, larger like marine mammals prey included.

“Megalodon’s large body size and potential energetic demands suggest that it would need/prefer highly caloric prey, like whales. Prey encounters relate with not only preference, but also prey availability and abundance,” Pimiento added.

It is a lack of abundance that potentially drove the megalodon into extinction, roughly 3.3 million years ago, during the Pliocene epoch. A 2016 study published in the Journal of Biogeography and authored by Pimento suggests that the megalodon’s demise came not from dramatic swings in the climate, but due to a decrease its primary food source at the time (baleen whales) and increase in other predatory sharks (the great white included) and whales in the Orcinius genus.

As the prehistoric ocean’s top predator and resident globetrotter, O. megalodon’s extinction would have post major changes on global nutrient transfer and ocean food webs throughout the world.

“The extinction of this iconic giant shark likely impacted global nutrient transport and released large cetaceans from a strong predatory pressure,” said Pimiento.

Correction (August 23, 2022): A previous version of this post stated that the megalodon weighed similarly to the Space Shuttle Endeavour. The Endeavour weighed around 4.4 million pounds fully loaded.

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Paleontologists in southern Argentina have recently discovered an adorable, five-foot-long armored dinosaur. The Jakapil kaniukura roamed the Earth during the hot and humid Cretaceous period roughly between 145.5 and 65.5 million years ago, and weighed 9 to 15 pounds–the size of the average domestic cat. 

The tiny dino’s fossilized remains were dug up during multiple digs over the over the past 10 years near a dam in Patagonia’s Río Negro province. The province is home to the La Buitrera palaeontological zone, a region well-known for the discovery of three complete southern raptors (Unenlagia) skeletons, herbivorous terrestrial crocodiles, the oldest found chelid turtles, and more.

Jakapil is part of the Thyreophoran dinosaur group that lived from the Jurassic period to the early Cretaceous period whose name means “shield bearer.” This feisty-looking group includes the bony backed, spiky tailed Stegosaurus and the tank-like Ankylosaurus. Like its prickly cousins, Jakapil had built in physical defenses, with rows of bony oval-shaped armor along its neck, back, and down to its tail.

[Related: This fossilized butthole gives us a rare window into dinosaur sex.]

“It bears unusual anatomical features showing that several traits traditionally associated with the heavy Cretaceous thyreophorans did not occur universally,” wrote the study’s authors, Facundo J. Riguetti, Sebastián Apesteguía, and Xabier Pereda-Suberbiola. “Jakapil also shows that early thyreophorans had a much broader geographic distribution than previously thought.”

The team published their findings in the journal Scientific Reports on August 11th. They first discovered Jakapil’s partial skeleton alongside 15 tooth fragments, which revealed that jakapil’s teeth were leaf-shaped like a modern-day iguana’s. 

According to lead paleontologist Sebastián Apesteguía, Jakapil marks the first-of-its-kind discovery of an armored dinosaur from the Cretaceous in South America. It also resembles a more primitive form of thyreophoran dinosaur that lived in the area significantly earlier. 

“Thyreophorans originated about 200 million years ago and rapidly evolved into various species distributed throughout the world,” Riguetti, first author of the work and a Conicet doctoral fellow at the Center for Biomedical, Environmental and Diagnostic Studies at Maimónides University said in a release. “However,of these early thyreophorans, the lineage represented by ‘Jakapil’ was the only one that lasted until at least 100 million years ago.”

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What do elephants, camels, and sauropod dinosaurs all have in common? Soft tissue pads beneath their heels support their enormous sizes and weights. A new study published in Science Advances found that sauropod dinosaurs were likely capable of evolving to heights up to 76 feet—almost as high as the White House—because their feet had cushions which helped their massive bodies move without crushing their foot bones.

The evolution of gigantic dinosaurs and how they carried their enormous stature has been a topic of debate among paleontologists for more than a century–that, until now, had no concrete answer. “What is exciting is that our research finally resolves this 120-year-old hypothesis by providing, for the first time, biomechanical evidence to show how gigantic sauropods could support their weight on land,” says Andréas Jannel, a research associate at The University of Queensland and lead author of the study. 

These gigantic plant-eating dinosaurs, iconic for their long necks and tails, roamed Earth in the Jurassic epoch as early as 201 million years ago. But it was not until 145 million years ago that they started evolving into bigger sizes—10 times the height of the modern-day African elephant. When paleontologists found the first sauropod tracks a century ago, Jannel says, the footprints seemed to show the animals were walking on heels. This led some paleontologists to speculate that giant dinosaurs had a kind of heel pad when walking—although there was no evidence to definitively support the theory. Hundred-year-old technology was unable to study soft tissue in fossils, which are rarely preserved in rock to begin with. 

[Related: Even dinosaurs couldn’t escape the sniffles]

Jannel and his co-authors created a new approach to study dinosaur foot anatomy that included the bones and soft tissue. Using fossil data from the Upper Triassic to the Upper Jurassic epoch, the researchers created 3D virtual models from five different sauropod species, which weighed between 1,984 to 74,957 pounds. They also created a model based on the foot of an existing African elephant. Virtually reconstructing the foot postures allowed them to track how the sauropods would walk on dry land with and without a soft tissue foot pad. 

Soft tissue pads underneath the heel were necessary for sauropod dinosaurs to walk without causing tissue damage or breaking any bones. Similar to elephants, the pad cushion directed the loads away from the bones.

Study author Olga Panagiotopoulou, a senior lecturer of anatomy and developmental biology at Monash University, says the idea of fleshy foot pads came from looking at the fat pads found in elephants, rhinoceroses, and other living giants. These animals evolved bottom cushions to serve as shock absorbers to redistribute the pressure on their feet. Panagiotopoulou says a 2011 study, which found that ancestral elephants evolved to have large foot fat pads as they grew in size, partly inspired their hypothesis that sauropods had similar structures to reduce the stress on their bones and avoid fractures.

[Related: Dinosaurs who stuck together, survived together]

Smaller members in the sauropod family, the scientists found, also shared their version of a cushy foot pad. Using the fossilized tracks of sauropod precursors known as Plateosaurus, the researchers created a reconstruction of their foot that had toes slightly raised off the ground with no heel pad. The results indicate there was no way the foot skeleton alone could support their weight without some form of additional padding. “Our work suggests that the presence of an incipient heel pad in sauropod precursors laid the foundations for the evolution of a more substantial structure,” says Jannel. 

Kimberley Chapelle, a Kalbfleisch postdoctoral fellow in the American Museum of Natural History’s Division of Paleontology who was not affiliated with the study, says before this paper, no other studies tested the theory of whether sauropods had fatty pads in their feet. “This provides yet another puzzle piece to how sauropod dinosaurs got so big.” Although Chapelle says her only reservation would be that, while the study methods were tested on a modern-day elephant, “it would have been useful to see what predictions the models made for other living animals that have fat pads such as camels and rhinos, as well as those who don’t.”

With evidence for fatty foot pads in sauropod dinosaurs, Panagiotopoulou says she is planning to investigate how exactly they distribute the stress of walking by studying the foot mechanics of elephants, rhinoceroses, and horses. 

Jannel, on the other hand, is working to expand the 3D computational models to an entire sauropod limb—complete with soft tissue such as muscles, which are also rarely preserved in fossils. “This research and methodology are relatively new in the field of paleontology,” he explains. “So stay tuned, because this has a lot of potential for more research in the future, not only in sauropods but also other dinosaurs and prehistoric animals!”

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It’s got to be out there. It doesn’t matter that Otodus megalodon has by all scientific accounts been extinct for more than 3 million years. The ongoing earthly presence of the enormous shark persists in our collective imagination thanks to rumors, legends, and summer B flicks.

Meg mythology often posits that the 50-foot predator has been hiding for epochs somewhere at the bottom of the ocean. It’s a notion that’s launched more than a few books and pseudo-docs, all hinging on the fact that most of the planet’s nether waters are unexplored—and therefore rife with primo dens for enigmatic beasts. But based on what we know of the biological adaptations required for life down below, not many animals could pull off a deep-sea disappearing act. If megalodon is still out there (and that’s a pretty big if), it’s not what it used to be.

Fossil shark teeth got people hooked on the Meg long before paleontology took off in the early 19th century, when scientists started cataloging fossils with gusto. In 1835, Swiss naturalist Louis Agassiz described triangular, finely serrated teeth, which had been found worldwide since antiquity, as belonging to a “megatooth” relative of the great white.

Discoveries around the world—in locations as diverse as Panama, Japan, Australia, and the southeastern United States—piled up over time, but one particular find raised the specter of a Meg still swimming in the deep. In 1875, during an expedition for the Royal Society of London, the HMS Challenger dredged up 4-inch-long teeth from a depth of 14,000 feet near Tahiti. In 1959, zoologist Wladimir Tschernezky, who made a hobby of researching “hidden animals” like Bigfoot, estimated the specimens were just 11,300 years old. Other scientists have since dismissed this dating, but unscrupulous documentarians and curious amateurs still highlight the research as a hint that Meg might persist.

Save for the outliers found by the Challenger, the megalodon’s fossil record indicates it was a shore-hugging creature, similar to its distant cousin the great white. “Remains generally come from coastal marine rock deposits formed in tropical-temperate areas,” says DePaul University shark researcher Kenshu Shimada. The species’s dietary habits further confirm a shallow lifestyle, with gnawed ancient whale bones showing Meg’s preference for marine mammals. These air breathers had to break through the surface for oxygen, so paleontologists expect megalodon, like them, hung out near the shore.

The exact combination of factors that pushed the ancient shark into extinction is still murky. We do know that shallower oceanic zones were undergoing dramatic changes around 3.5 million years ago, when the giant disappears from the fossil record. Water was growing cooler, making marine mammals less abundant, and the newly evolved great white may have served as a nimble competitor for resources. But there’s no way to prove definitively what did in the Meg.

The lack of certainty helps some maintain hope of finding one in the deep. Believers have at least one thing right: The bottom of the sea is an enigma. Even though satellites have mapped 100 percent of its floor, a low-resolution chart alone doesn’t give us great insight into what actually lives there, says Louisiana Universities Marine Consortium Executive Director Craig McClain, who specializes in cataloging oceanic systems. While the idea of a deep-dwelling ancient creature is highly improbable, he says, the sliver of possibility is still tempting. Less imposing critters have indeed shown up unexpectedly; in 1938 biologists identified a living coelacanth—a species of fish presumed extinct for about 65 million years.

If the megalodon were living in the dark, inky depths, though, it would have had to become a very different sort of creature—one we might not find nearly as cinematic. For one thing, Shimada says, its ravenous metabolism would need to fundamentally change. Preliminary geochemical analysis of isotopes in remains, which can help scientists estimate the body temperature of prehistoric organisms, indicates that megalodon was “warm-blooded” in the same sense as the great white. That predator’s active ocean cruising generates enough body heat to keep it toastier than surrounding seawater, an effort that burns through the equivalent of about six pounds of flesh a day. Meg may have weighed as much as three times more, and would have presumably required proportional grub. Yet animals near the ocean floor have to get by on teensy scraps, preying on the scant species that live there or hoovering up biological detritus that sinks down from carcasses above.

This scarcity of food tends to make organisms evolve small, efficient forms, making many low-living sharks relatively sluggish and slight. A megalodon living far enough down to evade human detection might now look something like a sleeper shark—a long, cigar-shaped animal that’s about as lively as it sounds—as opposed to a burly, toothy beast.

Yet even if Meg had assumed a slender and slow disguise, we’d probably have seen evidence of it by now. “Ocean giants that we do know about have global distributions,” McClain says. Even if we rarely spy creatures like giant squids, which live in the more forgiving upper ranges of what we’d call the deep sea, they leave markers of their existence strewn around the world in the form of carcasses (and bites taken out of unlucky critters). We’ve yet to spot any such refuse, if it even exists.

But these realities can’t extinguish the Meg’s enduring myth (and summer movie franchises). “As a deep-sea explorer and as a scientist who spends a lot of time researching known ocean giants, I really want there to be some unknown one that is undiscovered, and to make that discovery,” McClain says. Its mysterious nature—what we know of it comes largely from studying teeth—makes it enticing to imagine the Meg’s pulled off the ultimate vanishing act and could, perhaps, reemerge at any moment. The key is where scientists decide to look. While paleontologists are almost certain megalodon doesn’t swim in our modern seas, they might still find more details about the species in the depths of the fossil record—and its enduring secrets could break the surface when we least expect.

A history of the megalodon

16 million years ago – Otodus megalodon evolves from an ancestral group of megatooth sharks—the last member of a line that began 60 million years ago.

10 million years ago – The shark spreads to coastal waters worldwide. Clusters of baby teeth near Panama suggest nurseries were close to shore.

5 million years ago – Great white sharks evolve, and likely compete with the massive Meg to eat the same marine mammals, such as whales.

3.5 million years ago – Otodus megalodon seemingly goes extinct around a time of upheaval, including cooling seas and a dip in the species it munched on.

70 CE – Pliny the Elder notes that large “tongue stones” found in the rock strata of Europe may fall from the heavens during lunar eclipses.

1666 – Danish scientist Nicolas Steno dissects the head of a shark found off the coast of Italy and speculates that “tongue stones” are teeth.

1835 – Swiss naturalist Louis Agassiz coins the name Carcharodon megalodon in describing a set of the creature’s giant chompers.

1875 – The HMS Challenger dredges up megalodon teeth from the deep sea near Tahiti, fueling speculation about the shark’s survival.

1909 – Researchers build a model of a Meg jaw that fits six standing adults—suggesting an 80-foot body. This is now considered oversize.

1919 – Fishers in Australia claim to see a massive shark eat multiple lobster pots. The legend eventually makes its way into megalodon lore.

1974 – Peter Benchley publishes Jaws, which plays with the idea that a prehistoric man-eater might lurk in the deep. The public is hooked.

2016 – After decades of debate on the specifics of Meg’s family tree, the giant shark gets the new scientific name Otodus megalodon.

This story appears in the Fall 2020, Mysteries issue of Popular Science.

Is your head constantly spinning with outlandish, mind-burning questions? If you’ve ever wondered what the universe is made of, what would happen if you fell into a black hole, or even why not everyone can touch their toes, then you should be sure to listen and subscribe to Ask Us Anything, a podcast from the editors of Popular Science. Ask Us Anything hits Apple, Anchor, Spotify, and everywhere else you listen to podcasts every Tuesday and Thursday. Each episode takes a deep dive into a single query we know you’ll want to stick around for.

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When the first dinosaur fossils were recognized in the mid-19th century, scientists envisioned that the creatures were basically giant, lumbering lizards. They also presumed that dinosaurs were like present-day, cold-blooded lizards, meaning that their body temperature depended on the surrounding environment. However, this notion was later fiercely debated.  

“The general picture that we have of dinosaur physiology has changed quite a bit through the last [several] decades,” says Jasmina Wiemann, a molecular paleobiologist at the California Institute of Technology. “Our understanding of what dinosaurs looked like and lived like is directly related to the question of whether they were cold-blooded, warm-blooded, or somewhere in between.” 

A new analysis published by Wiemann and her collaborators on May 25 in Nature indicates that the ancestors of dinosaurs were warm-blooded, or capable of maintaining a constant internal temperature. The researchers used a new technique to estimate the metabolic rates of modern and extinct animals based on the molecular composition of their bones. They concluded that many iconic dinosaurs such as Tyrannosaurus rex and the giant sauropods were warm-blooded, but cold-bloodedness later emerged in some dinosaurs such as Stegosaurus. 

Enrico Rezende, an evolutionary biologist at Pontifical Catholic University of Chile who has studied the evolution of warm-bloodedness, or endothermy, calls the findings “quite impressive.”

The results are “not entirely surprising, but it’s definitely good to have some estimate of metabolic levels,” he says, explaining that it breaks away from rigidly categorizing dinosaurs as warm-blooded or cold-blooded. “Essentially what this shows is that we have this whole gradient of metabolic levels.” 

Modern lizards or crocodiles must bask in the sun to raise their body temperature, while warm-blooded animals such as birds and mammals don’t need to do this. Being endothermic could have allowed dinosaurs to be more active and range over larger areas, Rezende says. They would also be less vulnerable to chilly temperatures, which means they could be more active at night and would fare better on elevated terrain or at high latitudes. On the other hand, warm-blooded dinosaurs would require a lot of energy to fuel their high metabolisms, which means they would need to spend a lot of time feeding.

“Understanding the metabolic levels would tell us quite a lot about how they could interact and how these ecosystems could be built,” Rezende says.

[Related: Spinosaurus bones hint that the spiny dinosaurs enjoyed water sports]

Researchers have used various procedures to explore the extent to which dinosaurs were able to generate their own heat, says Lucas Legendre, a paleontologist at the University of Texas at Austin. One line of evidence comes from body temperature estimates based on temperature-sensitive minerals preserved in fossils. Other researchers study the growth rings in dinosaur thighbones to gauge how fast the animals grew. Legendre and his colleagues have also used blood vessel and bone cell size to infer that carnivorous dinosaurs had high metabolic rates close to those of today’s birds. 

The Nature paper indicates that, in terms of physiology, dinosaurs typically had more in common with their closest living relatives—birds—than with lizards, Legendre says. “This is a new piece of evidence that confirms what a lot of researchers have been saying for the past decade,” he says. 

For the new work, the researchers took a more direct approach than earlier investigations, says Matteo Fabbri, a paleontologist at the Field Museum of Natural History in Chicago and coauthor of the study. The team examined byproducts of metabolism—the process by which animals convert nutrients and oxygen into energy—preserved in newly-formed as well as fossilized thighbones. 

“It is the metabolism that determines whether a lot of excess heat is generated as part of the breathing process and whether an animal is cold-blooded or warm-blooded,” Wiemann says.

During this process, chemicals called reactive oxygen species form and generate molecules called advanced lipoxidation end-products. These leftovers build up and “leave a fingerprint in pretty much every tissue,” Rezende says. An animal with a high metabolic rate uses more oxygen than one with a low metabolic rate, so it should have higher levels of these compounds in its body. 

Wiemann and her team scanned the bones of 30 fossilized animals and 25 modern birds, mammals, and reptiles using techniques called Raman and Fourier-transform infrared spectroscopy. This allowed them to measure the accumulated amounts of advanced lipoxidation end-products. 

“We basically use these data to infer the evolution of metabolism,” Wiemann says. “What we figured out is that dinosaurs were ancestrally warm-blooded.”

[Related: The fiery end of the dinosaurs kicked off the golden age of mammals]

The findings indicate that endothermy independently evolved in the group encompassing dinosaurs and the flying reptiles known as pterosaurs, in mammals, and in marine reptiles known as plesiosaurs. The researchers calculated particularly high metabolic rates for a long-necked diplodocid, Allosaurus, and birds, while T-rex had a somewhat lower metabolic rate than other carnivorous theropod dinosaurs. Strikingly, several of their more distant relatives had metabolic rates on par with modern lizards, indicating they were cold-blooded, or ectothermic. These included Stegosaurus, Triceratops, and a duck-billed hadrosaur.

“That is quite fascinating because it means the range of metabolisms realized in dinosaurs is a lot broader than originally thought,” Wiemann says. “That brings up interesting questions as to what triggers the evolutionary increase or decrease in the metabolic rate, and what does this mean for the lifestyles of the animals?”

Researchers have previously suggested that warm-bloodedness helped prehistoric birds and mammals adapt during the mass extinction that killed off the rest of the dinosaurs about 66 million years ago. However, the evidence that many Late Cretaceous dinosaurs had high metabolic rates hints that other traits such as body size were probably key to the survivors’ success, Wiemann says.  

The findings will need to be verified with further analyses that include more extinct animals, Legendre says. Still, the metabolic byproducts Wiemann and her team probed offer a source of data that researchers can compare with other traits.

“The fact that they used this new method adds one additional piece of the puzzle,” Legendre says. “Hopefully we’ll be able in the next few years to come up with a more precise picture of how dinosaurs and their close relatives were able to produce metabolic heat.”

Updated (May 26, 2022): The headline of this story has been updated to better reflect the research study’s question and the debate about dinosaur endothermy.

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Excerpted from The Last Days of the Dinosaurs by Riley Black. Copyright © 2022 by Riley Black and reprinted by permission of St. Martin’s Publishing Group.

Picture yourself in the Cretaceous period. It’s a day like most any other, a sunny afternoon in the Hell Creek of ancient Montana about 66 million years ago. The ground is a bit mushy, a fetid muck saturated from recent rains that caused a nearby floodplain stream to overrun its banks. If you didn’t know any better, you might think you were wading on the edge of a Gulf Coast swamp on a midsummer day. Magnolias and dogwoods shoulder their way into stands of conifers, ferns, and other low-lying plants gently waving in the light breeze drifting over the open ground you now stand upon. But a familiar face soon reminds you that this is a different time.

A Triceratops horridus ambles along the edge of the forest, three-foot-long brow horns slightly swaying to and fro as the pudgy dinosaur shuffles its scaly, ten-ton bulk over the damp earth. The dinosaur is a massive quadruped, seemingly a big, tough-skinned platform meant to support a massive head decorated with a shield-like frill jutting from the back of the skull, a long horn over each eye, a short nose horn, and a parrot-like beak great for snipping vegetation that is ground to messy pulp by the plant-eater’s cheek teeth. The massive herbivore snorts, making some unseen mammal chitter and scramble in alarm somewhere in the shaded depths of the woods. At this time of the day, with the sun still high and temperatures above 80 degrees, there’s barely another dinosaur in sight—the only other “terrible lizards” plainly in view are a couple of birds perched on a gnarled branch peeking out from just inside the shadow of the forest. The avians seem to grin, their tiny insect-snatching teeth jutting from their beaks.

This is where we’ll watch the Age of Dinosaurs come crashing to a fiery close.

In a matter of hours, everything before us will be wiped away. Lush verdure will be replaced with fire. Sunny skies will grow dark with soot. Carpets of vegetation will be reduced to ash. Contorted carcasses, dappled with cracked skin, will soon dot the razed landscape. Tyrannosaurus rex—the tyrant king—will be toppled from their throne, along with every other species of non-avian dinosaur no matter their size, diet, or disposition. After more than 150 million years of shaping the world’s ecosystems and diversifying into an unparalleled saurian menagerie, the terrible lizards will come within a feather’s breadth of total annihilation.

We know the birds survive, and even thrive, in the aftermath of what’s to come. A small flock of avian species will carry on their family’s banner, perched to begin a new chapter of the dinosaurian story that will unfold through tens of millions of years to our modern era. But our favorite dinosaurs in all their toothy, spiked, horned, and clawed glory will vanish in the blink of an eye, leaving behind scraps of skin, feather, and bone that we’ll unearth eons later as the only clues to let us know that such fantastic reptiles ever existed. Through such unlikely and delicate preservation our favorite dinosaurs will become creatures that defy tense—their remains still with us, but stripped of their vitality, simultaneously existing in the present and the past.

The non-avian dinosaurs won’t be the only creatures to be so harshly cut back. The great, batwinged pterosaurs, some with the same stature as a giraffe, will die. Fliers like Quetzalcoatlus, with a wingspan wider than a Cessna and capable of circumnavigating the globe, will disappear just as quickly as the non-avian dinosaurs. In the seas, the quad-paddled, long-necked plesiosaurs and the Komodo dragon cousins called mosasaurs will go extinct, as well as invertebrates like the coil-shelled squid cousins, the ammonites, and flat, reef-building clams bigger than a toilet seat. The diminutive and unprepossessing won’t get a pass either. Even among the surviving families of the Cretaceous world, there will be dramatic losses. Marsupial mammals will almost be wiped out in North America, with lizards, snakes, and birds all suffering their own decimation, too. Creatures of the freshwater rivers and ponds will be among the few to get any sort of reprieve. Crocodiles, strange reptilian crocodile mimics called champsosaurs, fish, turtles, and amphibians will be far more resilient in the face of the impending disaster, their lives spared by literal inches.

[Related: If that asteroid had been 30 seconds late, dinosaurs might rule the world and humans probably wouldn’t exist]

We know the ecological murder weapon behind this Cretaceous case study. An asteroid or similar body of space rock some seven miles across slammed into Earth, leaving a geologic wound over fifty miles in diameter. Most species from the Cretaceous disappeared in the aftermath. It’s difficult to stress the point strongly enough. The loss of the dinosaurs was just the tip of the ecological iceberg. Virtually no environment was left untouched by the extinction, an event so severe that the oceans themselves almost reverted to a soup of single-celled organisms.

But the reason we’ve gone back to this place and this one infamous moment is to understand not only why there are no Ankylosaurus descendants at the zoo but also how and why we came to exist. The Age of Mammals, a marker literally set down in stone, would never have dawned if this impact hadn’t allowed for evolutionary opportunities that were closed for the previous 100 million years. The history of life on Earth was irrevocably changed according to a simple phenomenon called contingency.  If the asteroid’s arrival had been canceled or significantly delayed, or if it had landed on a different place on the planet, what transpired during the millions of years that followed the strike would have unfolded according to an altered script. Perhaps the non-avian dinosaurs would have continued to dominate the planet. Maybe marsupials would have held sway as the most common beasts. Perhaps some other disaster, like massive volcanic eruptions in ancient India that picked up around the same time, would have sparked a different sort of extinction. It’s likely that the Age of Reptiles would have marched on unimpeded, but without the origin of any species introspective enough to engage in such ruminations about time and its flow. This day was as critical for us as it was for the dinosaurs.

Buy The Last Days of the Dinosaurs here.

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More than 90 million years ago, a dinosaur similar in size to T. rex cruised through shallow waters in search of prey, scientists reported today in the journal Nature. 

A number of ancient reptiles such as plesiosaurs and ichthyosaurs are known to have had marine lifestyles, but dinosaurs have generally been considered landlubbers. However, an analysis of the density of 380 bones belonging to a variety of dinosaurs, other extinct creatures, and present-day animals suggests that the iconic Cretaceous dinosaur Spinosaurus and one of its close relatives were capable swimmers. 

Based on the new findings and other reports, it’s “strongly plausible” that Spinosaurus was an aquatic dinosaur, says Alexandra Houssaye, a paleontologist at the French National Natural History Museum in Paris who wasn’t involved in the research.

While Spinosaurus probably didn’t have the agility or diving abilities seen in today’s seals or dolphins, its bones suggest the enormous predator was more comfortable in water than on land and may have swam along the riverbed like a misshapen hippopotamus or crocodile, Houssaye says.

[Related: Most dinosaurs didn’t swim—but this ‘dino equivalent of Jaws’ sure did]

Spinosaurus belongs to a family of meat-eating dinosaurs known as spinosaurids that emerged during the Jurassic Period. They had narrow, crocodile-like faces and long spines along their backs that could grow to around 6 feet tall, says Matteo Fabbri, a paleontologist at the Field Museum of Natural History in Chicago and coauthor of the study. Although Spinosaurus wasn’t quite as heavy as T. rex, it was longer, with some specimens reaching an estimated 50 feet. 

The first Spinosaurus fossil was discovered in Egypt in the early 20th Century but was destroyed during World War II. During the 1980s and 1990s, researchers began to find fragmented fossils from Spinosaurus and its family members around the globe and surmised that spinosaurids were mostly land dwellers that sometimes waded through the water in search of fish, similar to present-day herons. 

Then in 2014, a Spinosaurus skeleton in unusually good condition was identified in Morocco. “It’s created a huge debate in the field of paleontology,” Fabbri says. He and his collaborators noted a number of traits, including stubby hindlimbs and paddle-like feet, that hinted that the dinosaur was at least partly aquatic. In 2020, the team reported that Spinosaurus’s tail had an unusual fin-like shape that could have propelled it through the water similarly to the tails of modern crocodiles. 

Still, Fabbri says, it can be difficult to judge how much time an animal spent underwater by the shape of its bones. Today’s whales and seals have plenty of skeletal characteristics that reveal their aquatic tendencies. But in other water-loving species, such as hippos and tapirs, these features aren’t as obvious. 

Even though they have a well-documented aquatic lifestyle, “if you look at skeletons of hippos they look much more like terrestrial animals than anything else,” Fabbri says. “So is it possible that maybe we’re underestimating the ecological diversity of the fossil record because we are only focusing on anatomy?”

To address this question, he and his colleagues measured the bone density of Spinosaurus and two other spinosaurids, Baryonyx and Suchomimus, and compared them to other dinosaurs and extinct reptiles, Cretaceous birds, as well as a wide array of modern birds, mammals, and reptiles. The researchers examined the thighbones and ribs of their specimens using CT scanning and by examining thin slices of bone under the microscope.

“Higher density means there’s more tissue per single volumetric unit,” Fabbri says. “If you are an aquatic animal…if you are denser you can sink easily, and therefore you have more buoyancy control.”

Animals that submerge themselves underwater, such as hippos, manatees, crocodilians, and penguins, have denser bones than terrestrial animals and aquatic animals that dive deeply to search for food, including ichthyosaurs and modern whales and seals. These more active swimmers rely on their own movements, rather than bulky bones, to control their buoyancy, Houssaye says. When land-dwelling animals such as the ancestors of today’s whales take to the water, dense bones evolve early in the transition. “​​The inner structure changes more quickly than the shape of the bones,” she says.

Fabbri and his team observed that generally an animal’s bone density was mostly unrelated to its body size. They also noted that flying animals were somewhat more likely to have lightweight bones, and the densest bones were found among aquatic animals. In shallow-water specialists, he says, “You don’t have this donut-shaped cross section where you have bone outside and emptiness in the middle; you simply have a lot of bone that reaches to the center.”

The researchers found that both Spinosaurus and Baryonyx had extremely dense bones, similar to penguins, cormorants, and plesiosaurs. They may have returned to land to lay their eggs, Fabbri says, but probably spent most of their time in the water. 

[Related: These ancient, swimming reptiles may have been the biggest animals of all time]

On the other hand, Suchomimus had bones more similar to the other dinosaurs included in the analysis, suggesting it didn’t hunt underwater like its cousins. However, Suchomimus’s elongated snout and cone-shaped teeth suggest that it did feed on fish, and may have waded along riverbanks. 

Most dinosaurs probably weren’t built for living in the water, Fabbri says. Nonetheless, there may be other extinct animals who were better suited for swimming than scientists have previously assumed based on the shape of their bones. The next step, he says, is to measure the bone density of a broader array of dinosaur fossils.

“The fossil record is pretty patchy, meaning that a majority of skeletons are very fragmentary,” Fabbri says. “So this was very exciting because it was a way to say, okay not only can we understand the ecological adaptations in the fossil record, but you don’t need a full skeleton to understand it.”

One limitation of the analysis is that very compact ribs are sometimes seen in land animals, Houssaye notes, so these bones aren’t necessarily indicative of an aquatic lifestyle. Still, the densely-packed thighbones Fabbri and his colleagues observed in Spinosaurus do suggest that these dinosaurs were water dwellers. In the future, she says, researchers may find more evidence for Spinosaurus’s aquatic nature by examining the density of additional bones such as the forelimbs and investigating whether density is consistent throughout the length of the bones.  

“Because there are not many bones, we need to exploit them as much as possible,” she says.

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Tyrannosaurus rex, whose name translates to the tyrant lizard king, has long charmed the public as the star dinosaur in the Jurassic Park series. But the scene-stealing dino is stealing the spotlight again—this time, in a drama over how it should be classified. A controversial new study published in the journal Evolutionary Biology suggests that there may not just be one species in the Tyrannosaurus monarchy, but three, with T. regina and T. imperator as the long-lost cousins of T. rex. 

All hail the king (rex), queen (regina), and emperor (imperator) of the prehistoric kingdom? Not so fast, say other researchers, who argue would-be differences in the fossil specimens are too minor to support such a dramatic rift. 

To divide an extinct organism into species A, B, and maybe even C, there needs to be “enough separation” between the groups in the fossil record, says Ashley Poust, a paleontologist at the San Diego Natural History Museum who wasn’t involved in the study. He calls it “one of the biggest problems” of species identifications that only rely on what the eyes can discern.

Tyrannosaurus rex dominated the food chain in Northern America from 68 million to 66 million years ago. Over its two-million-year reign, members of the Tyrannosaurus genus could have spun off into several species, says Paul Sereno, a paleontologist at the University of Chicago who also wasn’t involved in the study. Just like the assortment of today’s predators roaming the African Serengeti, from lions to cheetahs to leopards, the top carnivores of the late Cretaceous period could have similarly diverged. 

“It’s difficult to believe that one species could [have lasted] millions of years across that expansive territory, with the amazing amount of herbivores that were out there to be eaten,” says Sereno. 

[Related: It was probably springtime when an asteroid did the dinosaurs in]

The study authors use two skeletal features, the stockiness of the femur and the number of teeth, to argue that T. rex should be redefined as three species. They recorded the length and diameter of thigh bones from 37 specimens. With their data, they gleaned that some Tyrannosaurs could be of a chunkier variety with a more robust femur. Or, the dinosaurs could have slender builds, as suggested by slimmer bones.  

Moreover, the researchers propose that different Tyrannosaurus species could either have one or two incisors per skull—the sharp tooth adapted for ripping into flesh. The collaborators named the stockier, double-incisor carnivore T. imperator. Another hunky species with one incisor remained T. rex. Finally, they called the single-incisored, svelte dinosaur T. regina. 

“This is a fairly subtle example of evolution [and] speciation,” says study author Gregory Paul, a freelance paleontologist. He thinks that as new Tyrannosaurus fossils are discovered, the larger sample size might allow researchers to run statistical analyses to unearth fresher findings about the tyrannical beasts. “Science is not dogmatic,” he adds, and what the world knows about the prehistoric lizard monarchy “is not set in stone.” 

But two bodily features aren’t enough to tell different species apart, says Thomas Carr, a vertebrate paleontologist at Carthage College in Kenosha, Wisconsin, who didn’t participate in the study. Carr previously analyzed 1,850 attributes of Tyrannosaurus fossils, and concluded that the dinosaur should remain under one species. There was no meaningful clustering among the attributes to bifurcate T. rex into multiple species. If a checklist of nearly 2,000 traits can’t justify the existence of T. rex‘s long-lost cousins, two indefinite patterns just won’t cut it, says Carr. 

“The features that identify species are utterly unique, smack-in-the-face-with-a-frying-pan obvious,” he notes. He thinks that femur size and incisor number shouldn’t qualify, given that the study couldn’t identify a quarter of the Tyrannosaurus specimens using the same metrics, despite the nearly perfect conditions of their skulls. 

Any differences perceived in this study can be chalked up to variation among individuals within a species, Carr adds, like how Homo sapiens can come in different shapes, sizes, and skin tones. 

[Related: How do we know what dinosaurs looked like?]

Other experts agree that the two features selected in the study aren’t distinct enough to diagnose different species. Jingmai O’Connor, an associate curator of fossil reptiles at the Field Museum of Natural History, Chicago, has a bone to pick with the vaguely descriptive terms peppered throughout the paper, including qualifiers such as “generally” and “usually.” She says such analysis might be “arbitrarily drawing the line in all the variation” when the disparities between the three supposed groups aren’t clear-cut at all. 

The Field Museum houses Sue, the world’s most complete T. rex skeleton and possibly one of the biggest. For now, Sue will keep its designation of king, despite the study suggesting its reclassification to the rank of emperor. 

It’s plausible that there were multiple species of Tyrannosaurus during their heyday, says Poust from the San Diego Natural History Museum. But he also thinks that the study’s fossil evidence might be insufficient to back the claim up and warrant the naming of new dinosaurs. “[The authors] look at species in a way that’s a little unclear,” he says. “If I went to the field and I dug up a Tyrannosaurus skeleton and looked at it, could I really easily tell which of these species it’s in?” 

Results aside, Carr of Carthage College is also concerned that half of the specimens in the new research are privately owned Tyrannosaurus fossils, which is a violation of the ethical standards of the Society of Vertebrate Paleontology. Relics from private collections aren’t necessarily accessible to all those who want to analyze them, so studies that use them might not be reproducible and verified by other experts.

Among the specimens in the Evolutionary Biology study is the near-complete fossil Stan, which was auctioned off to an anonymous bidder for a record-breaking $31.8 million last October. Since then, paleontologists have feared that the T. rex specimen, whose whereabouts are now unknown, might be lost to science forever. “I wouldn’t touch that stuff with a 10-foot pole,” says Carr. “We have to stick with museum and university collections that are there to provide fossils for study for all time.” 

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The dinosaur-killing asteroid that smashed into present-day Mexico 66 million years ago arrived in springtime, a new analysis suggests.

Scientists examined fossilized fish that perished shortly after the impact and used the growth patterns and chemicals preserved within the bones to pin down the timing of the event. The researchers concluded that the asteroid strike occurred during spring in the Northern Hemisphere, a time when many animals would have been raising young and especially vulnerable to the cataclysm. The season in which the asteroid made contact likely influenced which species survived the mass extinction that followed, the team reported on February 23 in Nature.

“The results of this study may help explain why some organisms went extinct at the end of the Cretaceous while others weathered the catastrophe,” Michael Donovan, a paleobiologist at the Cleveland Museum of Natural History who wasn’t involved in the research, said in an email. 

The asteroid’s immediate aftermath included forest fires, tsunamis, and rocky fallout that reached areas more than 2,000 miles from the Chicxulub impact crater in Mexico’s Yucatán Peninsula. One site that preserves evidence of these disturbances is the Tanis event deposit, which lies within the fossil-rich Hell Creek Formation in North Dakota.

Within tens of minutes after the asteroid impact, a seismic shockwave would have shaken the Tanis river and created a surge of water that hurled fish, ammonites, and other marine creatures ashore. Meanwhile, fragments of molten and vaporized rock called spherules, which were blasted into the atmosphere and resolidified, rained down upon the unfortunate animals as they were buried alive. 

“The shockwave moves very fast through the Earth’s crust and causes huge waves in the overlying bodies of water (lakes, rivers); very similar to a pool during an earthquake,” Melanie During, a PhD student in vertebrate paleontology at Uppsala University in Sweden and coauthor of the findings, said in an email.

To determine when this turmoil took place, During and her collaborators examined filter-feeding paddlefishes and sturgeons found in the deposit with spherules caught in their gills. Micro-CT scans of one of the skeletons revealed that the rock fragments hadn’t yet reached the digestive tract, confirming that the fish died very soon after impact. 

The researchers also peered at fine slices of the fishes’ fin spines and jawbones under the microscope. These bones grow similarly to trees, During said, adding a new layer every year. 

She and her team observed the tiny pores in each layer that once housed bone cells, which grow in size and density during the warm months when food is plentiful. “[We] saw that all these fishes recorded seasonality and died exactly at the same time: Spring,” During said.

The researchers next analyzed how the different types of carbon atoms, or isotopes, in the growth rings varied throughout the year. The fish receive “heavier” carbon isotopes from tiny creatures called zooplankton they dine on. When the fish died, the ratio of heavy carbon isotopes to lighter ones was increasing but hadn’t quite reached its typical summertime peak. This provided another piece of evidence that the fish met their end during the spring. 

“The actual extinction took far longer than just this moment itself,” During acknowledged. But the catastrophic season—spring in the Northern Hemisphere, and fall in the Southern one—would have eliminated many organisms even before the asteroid’s fallout enveloped Earth in nuclear winter, she said.

For many organisms, spring is the prime season for growth and reproduction after the harsh winter months, During said. As a result, the effects of the environmental devastation that followed in the asteroid’s wake may have been magnified for life in the Northern Hemisphere, Donovan added. 

Plants and animals in the Southern Hemisphere, which was in the midst of autumn, might have fared better; the asteroid arrived at a time when mammals were preparing to hibernate in burrows and insect pupae and dormant seeds were tucked away in the soil. 

[Related: June was probably a terrible month to be a dinosaur. Here’s how we know.]

Donovan and other researchers have previously reported that ecosystems in the Southern Hemisphere may have recovered more quickly from the mass extinction unleashed by the asteroid than Northern ecosystems. The new study may help explain the difference, he said, although many questions about this harrowing period remain.

“Were differences in regional recovery patterns a result of the distance from the asteroid impact site, variation in local climates, the season during which the impact occurred, or some combination?” Donovan said.

As researchers continue to investigate how the extinction that wiped out the dinosaurs unfolded across the planet, During said, one challenge is the relative scarcity in data from the Southern Hemisphere.  

There has been a “tremendous bias” toward studying this event from fossil finds in the Northern Hemisphere, with many more gaps in Southern Hemisphere data, During said. “It is absolutely worth it to concentrate on extracting more fossils from the Southern Hemisphere,” she said, “and doing so by including and supporting the local researchers who often lack funding to do their research.”

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Around 150 million years ago, a long-necked dinosaur in southwest Montana became very ill. The unfortunate sauropod might have endured a sore throat, headaches, and difficulty breathing. 

Although the dinosaur in question is long dead, signs of this sickness are preserved in its neck bones as lumpy growths. These abnormal structures may have been caused by a fungal infection similar to those seen in birds today, a team of paleontologists, veterinarians, and other anatomy specialists have determined. The growths represent the first evidence of a dinosaur respiratory infection and could shed light on certain aspects of dinosaur physiology, the team concluded on February 10 in Scientific Reports.

“I’ve looked at sauropods from all over the world and I’ve never seen a feature like this before,” says Cary Woodruff, the director of paleontology at the Great Plains Dinosaur Museum in Malta, Montana and a couthor of the findings. “It helps us understand the world that these dinosaurs were in—what kinds of illness and diseases plagued the tyrant lizards.”

Many of the ailments that struck dinosaurs are likely to remain a mystery because they left no trace on the bones. However, paleontologists have found fossil evidence of a host of maladies ranging from tooth infections to broken bones, arthritis, and cancer.

The dinosaur that Woodruff and his team examined was originally discovered in 1990 and nicknamed “Dolly” in honor of Dolly Parton. The fossil is similar in appearance to diplodocus, another long-necked herbivore that lived during the Late Jurassic. Dolly was probably between 15 and 20 years old when it died and reached a length of around 60 feet.

[Related: Duck-billed dinosaurs had the same bone tumors as people]

When Woodruff and his colleagues examined Dolly’s vertebrae, they noticed something odd.

Dinosaurs share numerous anatomical features with their living avian relatives and are thought to have breathed similarly to birds, he says. The respiratory system is more efficient in birds than mammals, with extra air sacs in the lungs and structures that penetrate into the bones. Dinosaurs also have sockets where respiratory tissue connects to the bone known as pleurocoels. “I like the analogy of a vacuum cleaner,” Woodruff says. “The respiratory tissue is like the hose, the bone is like the vacuum canister, and where that hose joins into the vacuum is the pleurocoel.”

Normally the bone in this region is very smooth. But in Dolly, the edges of pleurocoels on both the left and right sides of multiple vertebrae were knobbly and rough—a bit like a fossilized piece of broccoli. “Sticking out of it was this really gnarly, lumpy, irregular abnormal bone growth,” Woodruff says. “That was the smoking gun that this is not normal.”

To understand what might have caused the growths, he and his team searched for similar disorders among Dolly’s closest living relatives: birds and crocodilians. In crocodilians, the respiratory tract is “not as developed” as in birds, Woodruff says, and the respiratory tissue doesn’t pervade the bones. However, birds can develop respiratory infections that spread to the bone in the same location as Dolly’s lesions. 

To narrow down the type of infection Dolly suffered from, the researchers took CT scans of the afflicted vertebrae. In modern birds, some respiratory illnesses cause rind-like growths to develop on the outside of the bone. But in Dolly, the scans suggested, the interior of the bones was also “really screwed up,” Woodruff says. 

Unsurprisingly, no present-day ailments offered a perfect match for the ancient reptile’s growths. However, Dolly’s condition was most consistent with a very common infection called aspergillosis, which develops when birds, and humans, breathe in certain fungal spores. 

By the time such infections reach the bone, they’ve already had plenty of time to wreak havoc on the lungs and associated tissues. Birds with aspergillosis often cough, develop fevers, and lose weight. If a sick bird doesn’t receive treatment, the disease can lead to deadly pneumonia, much as COVID-19 does in people. 

All in all, Dolly would have felt pretty crummy. 

“We can’t say if Dolly just keeled over because of this disease, or just being so visibly sick or on its own from the herd was an easy target for predators,” Woodruff says. “But we can say in one way or another it ultimately caused the death of this animal.”

While Dolly probably didn’t have quite the same disease seen in today’s birds, its bony growths support the idea that dinosaurs were susceptible to fungal respiratory infections and may offer insights about how their immune systems worked. “Mammals and birds have very different immune systems, so if we have this non-bird dinosaur that was breathing like birds and has a bird-like respiratory infection, odds are its immunological response was much more like a bird than mammals or other reptiles,” Woodruff says.

The findings open up a “whole new dimension” in our understanding of dinosaur diseases, while providing a new insight into the musculoskeletal system of sauropods, says Ali Nabavizadeh, a comparative anatomist and paleobiologist at the University of Pennsylvania School of Veterinary Medicine who wasn’t involved with the research. Dolly’s infection also reinforces connections between dinosaurs and modern bird anatomy.

“This paper provides yet another piece of evidence to show just how modern dinosaurs—the birds—are biologically so similar to their extinct non-avian dinosaurian relatives, even to the point of showing similar diseases,” he said in an email. 

In the future, searching for similar lesions in sauropod vertebrae in collections around the world might reveal how prevalent respiratory infections were in these dinosaurs, Nabavizadeh said.

“I am excited to see how these findings can improve upon our knowledge of respiration as well as circulation in these breathtakingly enormous creatures.”

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Michael J. Benton is a professor of Paleobiology, University of Bristol. This story originally featured on The Conversation.

The dinosaurs were killed by a meteorite impact on the Earth some 66 million years ago in what has become known as the Cretaceous-Paleogene extinction event. At what time of the year this occurred has long generated debate among palaeontology enthusiasts.

A recent study published in Nature builds on earlier evidence to suggest the dinosaurs probably met their demise in June. The fact that researchers have been able to pinpoint the timing of an event that happened millions of years ago is a remarkable feat of science—but more on that later.

The latest evidence comes from a site called Tanis, located in the Hell Creek Formation in North Dakota. Tanis is one of several geological locations around the world where scientists have observed the Cretaceous-Paleogene boundary in the succession of sediments.

Tanis has yielded wonderful fossils of dinosaurs, early mammals, fish, plants and other things. Many of these fossils are exceptionally well preserved, with some showing remains of soft tissues, such as skin, as well as bones, which can offer valuable scientific insights.

The Tanis site was first identified in 2008 and has been the focus of fieldwork by palaeontologist Robert DePalma since then. In a 2019 paper, DePalma and his colleagues argued that Tanis captured the moment of the asteroid’s impact, due to three factors.

The first was the presence of dinosaur fossils occurring in the Cretaceous sediments right up to the Cretaceous-Paleogene boundary, and exactly at the boundary at the time of impact.

The second was a layer of melt spherules: tiny glass balls that cooled in flight from molten rock. When the asteroid struck Earth in the region of what is now the Yucatán Peninsula in Mexico, it spread debris and melt spherules for thousands of kilometers.

The third was evidence of seiche waves (see-saw-like standing waves) in deep channels. The Tanis site is well inland today, but at the end of the Cretaceous period it was located on the coast of the western interior seaway that divided North America at that time, with sea levels some 200 metres higher than they are today. The site was estuarine, which means fresh and salt waters were mingling.

The seiche waves were generated by the distant impact in Mexico, which set off seismic waves that shook the Earth and caused water to flow in and out of the river channels at a fast rate, estimated as beginning one hour after the impact.

As well as melt spherules within the fossil-bearing rocks, the researchers found abundant spherules in the gill skeletons of some of the fish they examined. We can imagine that as they floundered in the violently oscillating waters of the river channel, they could have swallowed melt spherules coming from above.

Looking more closely at the fish

In December 2021, DePalma and his colleagues published an important paper about the timing of the Cretaceous-Paleogene extinction event. In this study, they analysed some of the exceptionally well-preserved fish bones, looking at how the cycle of seasons, from summer to winter, were documented in the structure and chemistry of the bones.

By comparing living sturgeon to sturgeon fossils from Tanis, they found that in a fin spine, regular layering at a scale of millimeters shows the fish died when it was seven years old. The growth rings confirm the fish alternated between fresh waters in summer months and saline waters in winter. In this and other specimens analyzed in the same study, the last growth increment matches the transition from spring to summer.

Taken together, this suggests the meteorite struck in May or June, being the cusp of spring and summer in the northern hemisphere.

Importantly, these findings confirm earlier evidence based on fossil plants, which suggested the extinction event took place in early June.

Palaeobotanist Jack Wolfe identified a location in Wyoming that showed the effect of the meteorite on a freshwater lake. At the point of impact, the lake froze, preserving fossil plants in exquisite detail.

By comparing the fossil plants to similar modern water lilies Nuphar and Nelumbo, he showed that the latest Cretaceous water lilies in the lake had been halted in their growth at a point in their trajectory of producing summer leaves, flowers, and fruit which indicated freezing in early June.

Palaeontologists often say they would need a time machine to understand the details of past life, such as the month the dinosaurs died out. But here we see extraordinary conclusions can emerge from careful analysis and rational comparison with the modern day.

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Location is everything, for both homeowners and dinosaurs. When you’re buying a house, it’s better for your long term happiness to find a neighborhood you like that’s close to work instead of having that extra living room. And when you’re a Cretaceous period dinosaur, it’s better for your long term survival to have a giant asteroid hit in the middle of the ocean instead of just off the coast of Mexico.

If that meteor had come just half a minute later, it would have hit somewhere in either the Atlantic or Pacific. Either location would have made some killer waves (literally), but at least it wouldn’t have killed as many dinos. Birds are cool and all, it just might have been nice to have some little raptors running around instead of chickens. They were about the same size anyway, so they couldn’t reach the doorknobs if we put them a little higher. These new findings came to light in a BBC documentary, The Day the Dinosaurs Died, featuring the scientists who have been drilling into the underwater crater. Back in 2016, geophysicists Jo Morgan from Imperial College London and Sean Gulick from the University of Texas drilled deep into the ocean floor to figure out more about the impact. They’ve been analyzing the samples they brought back ever since. The Lunar and Planetary Science Conference in March 2017 featured multiple presentations from the team, but surprisingly the news didn’t really spread until their findings hit mainstream TV.

It’s important to note before we get into more details that there’s no causal evidence here. One of the leading theories for the mass extinction of non-avian dinosaurs is that there was (at least one) massive impact event that caused a series of catastrophic outcomes that devastated the largest flora and fauna. But it happened 66 million years ago. The Chicxulub crater off the coast of Mexico has been dated to that same era, so the timelines match up, but it’s just still situational data. And the impact theory isn’t the only one out there. Paleontologists don’t all agree that the Chicxulub crater is responsible for the mass extinction, though the data does strongly support the impact theory.

So, assuming that in fact there was one big impact that killed off most dinosaurs, the meteor responsible hit near the Yucatan Peninsula, where it was free to kick up dust from vaporized rock and sulfur dioxide. Sure, plenty of feathered dinosaurs died from the explosive force of the asteroid hurtling towards them—it was equivalent to about ten billion Hiroshima-sized nuclear bombs—but lots of them died later, too.

Let’s not forget about the worldwide cooling that began with all that sulfur dioxide. Unlike greenhouse gases, sulfur dioxide has a chilling effect that caused many more deaths as the world began to freeze. The vaporized rock blacked out the sun and ushered in more snow than anyone really wanted to deal with (disclaimer: Popular Science cannot verify whether some Cretaceous species did in fact enjoy the snow. They may have frolicked and made snow angels for all we know). Lots of animals weren’t prepared for that kind of sudden cooling (they hadn’t invented Canada Goose jackets yet) but you know who was? Humans. Well, not humans, but the ancient mammalian ancestors of a lineage that would someday produce humans.

And thank god they did, because with dinosaurs out of the way our squishy bodies and pathetically helpless babies were free to flourish. Our tiny mammalian predecessors survived a mega-earthquake, a chorus of volcanic eruptions, acid rain, and watched most of the plants they ate die. And they lived to tell the tale. Again, not really, because in all likelihood they didn’t have a language sophisticated enough to communicate a story. Modern prairie dogs can talk about people’s shirt colors, but even they can’t spin a yarn about “that time almost everything died.” Probably.

Our very-distant ancestors were right there alongside ancient crocodiles and sharks and gosh darn it, they prevailed. We have since made it out of the food chain, with the exception of those people who try to befriend those godless killing machines: bears. And apparently, none of it would have been possible if that meteor had shown up 30 seconds later. The early bird catches the worm—but it still sucks for the worm.

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Scientists have identified an extremely rare fossilized dinosaur embryo in an egg from southern China.

The late-Cretaceous specimen belongs to a group of dinosaurs called oviraptorosaurs, which are closely related to birds. Intriguingly, the embryo’s position resembles the “tucking” posture that modern birds assume before hatching. The findings indicate that this important adaptation evolved before birds split off from other dinosaurs, the researchers reported on December 21 in the journal iScience.

“Dinosaur embryos are key to the understanding of prehatching development and growth of dinosaurs,” Fion Waisum Ma, a PhD student in paleobiology at the University of Birmingham in the United Kingdom and coauthor of the findings, said in an email. While fossilized dinosaur eggs are abundant, however, embryos are much harder to come by. The dinosaur embryos that paleontologists have found are usually incomplete, with bones that have separated and become jumbled. 

By contrast, the newly described fossil includes an almost complete skeleton with bones arranged much as they were in life. “This little dinosaur is beautifully preserved in a fossilized egg,” Ma said. “We suspect the egg was buried by sand or mud quickly enough that it was not destroyed by processes like scavenging and erosion.”

She and her colleagues were able to reveal more than half the skeleton, with the rest still covered by rocky material in the egg. The fossil, originally discovered in an industrial park in China’s Jiangxi Province, dates to roughly 71 million to 65 million years ago. The elongated egg is 16.7 centimeters (6.6 inches) long and 7.6 centimeters (3 inches) wide, while the skeleton curled inside has a total length of 23.5 centimeters (9.3 inches).

[Related: A newfound South American dinosaur had a tail like a war club]

Oviraptorosaurs have been found in present-day North America and Asia. This dinosaur family is known for its diverse variety of skull shapes, including some with very tall crests. Had the embryo hatched, it probably would have grown into a medium-sized oviraptorosaur, Ma said, perhaps reaching 2 to 3 meters (6.6 to 9.8 feet) in length. The dinosaur would have been covered in feathers and had a toothless skull. 

The researchers compared the embryo’s anatomy with that of other oviraptorosaurs and theropods, the broader category of carnivorous dinosaurs that also includes Tyrannosaurus rex. The researchers also examined a fine slice of eggshell under the microscope and analyzed the evolutionary relationships among oviraptorosaurs to determine where the new embryo fell on the family tree. They concluded that the embryo belonged to a subgroup of oviraptorosaurs called Oviraptoridae. 

“The most surprising observation is the posture of this specimen—its body is curled with the back facing the blunt end of the egg, [and] the head below the body with the feet on each side,” Ma said. “This posture has never been recognized in a dinosaur embryo, but it is similar to a close-to-hatching modern bird embryo.”

To prepare for hatching, bird embryos reposition themselves in a process known as tucking. The oviraptorid fossil Ma and her team examined is arranged much like a 17-day-old chicken embryo in the first, or pre-tucking, phase. Over the next three days, a chicken embryo would gradually move into the final tucking posture, in which the body is curled with the head under the right wing. This posture seems to stabilize and direct the head while the bird cracks the eggshell with its beak, Ma said.    

She and her colleagues suspect that several previously discovered oviraptorid embryos are also arranged in various phases of tucking, although it’s hard to be certain because those specimens aren’t as well-preserved. Still, the team concluded that oviraptorids and modern birds may have used a similar strategy to maximize their chances of hatching successfully, unlike their more distant cousins such as the long-necked sauropods and living crocodilians.

[Related: Whoa, dinosaur eggs looked more dope than we thought]

“Tucking behaviour was usually considered unique to birds, but our new findings suggest that this behaviour could have existed and first evolved among theropod dinosaurs—the ancestors of modern birds,” Ma said.

To confirm this possibility, however, researchers will have to unearth more fossilized embryos of theropods and other kinds of dinosaurs to compare with modern birds and crocodiles. Ma and her colleagues also plan to investigate the skull and other body parts of this embryo still hidden within the rock.

“We hope to answer more questions about dinosaur early development and growth with this exceptional specimen,” she said.

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A new species of armored dinosaur from subantarctic Chile boasted a large tail weapon that looked dramatically different from those found on its relatives, and may shed light on a mysterious phase in the group’s evolution. 

Scientists found the mostly-complete skeleton in 2018 in the Río de las Chinas Valley of Chilean Patagonia and determined it to be roughly 71.7 to 74.9 million years old, dating it to the late Cretaceous. When they further examined the skeleton, the researchers found a baffling mixture of features typically seen in ankylosaurs and stegosaurs. However, its “bizarre” tail didn’t seem to match with the tails seen in either of these famous groups; rather than the traditional spikes or clubs, the newly-named Stegouros elengassen had seven pairs of bony deposits encasing half the tail in a flattened frond-like structure, the researchers reported on December 1 in Nature. 

Still, an analysis of the armored dinosaur family tree revealed that the fossil belonged to an ankylosaur, suggesting that different branches of the group flourished in the northern and southern hemispheres after the supercontinent Pangaea broke up. 

“This is the first time scientists get a good look at what a South American ankylosaur is like,” says Alexander Vargas, a paleontologist at the University of Chile in Santiago and coauthor of the study. Stegouros’s tail weapon, he adds, is “absolutely unlike anything we have seen before.”

A number of present-day mammals and reptiles, including porcupines and alligators, use their tails as whips or lashes to defend themselves from predators or rivals. But southern African girdled lizards go a step farther: Their tails are equipped with bony spines. More elaborate versions of these tail armaments were once wielded by extinct relatives of turtles and armadillos. 

“But the champions of them all are the armored dinosaurs,” Vargas says. In addition to the bony plates and spines along their backs, some members of this group developed specialized tail weapons. These included the tail spikes seen in stegosaurs such as Stegosaurus and rounded tail clubs belonging to ankylosaurs such as Ankylosaurus.

The ankylosaurs generally had broad backs and thick limbs. While ankylosaur fossils are plentiful in North America and Asia, Vargas says, until now only fragmented bones and teeth have been found of their more southern cousins. 

“These scraps and pieces were often interpreted as a sign that ankylosaurs, which in North America were very abundant and diverse, somehow managed to cross into South America, to migrate,” he says.

The specimen that he and his colleagues discovered in 2018 at the southern tip of South America changes this picture, Vargas says. When the team began to excavate the fossil, they first noticed its slender limbs and speculated that the specimen might have been a bipedal herbivore. Next came the tail with its “astonishing weapon,” Vargas says, which indicated that the skeleton actually represented some kind of armored dinosaur. 

“We thought we might have a stegosaur when we uncovered the hips,” he says. “They were identical to a stegosaur.” The fossil’s upper arm and right hand also resembled those of stegosaurs. Yet when the team reached the skull, they found that the upper jaw and palate looked distinctly ankylosaurian.

[Related: An overlooked fossil turned out to be a new herbivorous dinosaur with an oddly shaped nose]

To find out which group the puzzling species belonged to, the researchers analyzed hundreds of different traits from dozens of dinosaur species and ultimately identified ​​Stegouros as an ankylosaur. What’s more, its ancestors split off from the rest of the ankylosaurs some 167 million years ago in the mid-Jurassic. 

“It’s an evolutionary link between the ankylosaurs…and other armored dinosaurs like the stegosaurs,” Vargas says. 

This could explain why Stegouros bears so little resemblance to most ankylosaurs, with its agile limbs, narrow feet, light armor, and a hawk-like beak. The petite ankylosaur was only about 2 meters (6.6 feet) long and had a shorter tail than other armored dinosaurs. The weapon’s flattened shape might have made it easier for Stegouros to avoid dragging its tail and “being able to wield it for defense,” Vargas says. He and his colleagues named the structure after an Aztec war club, or macuahuitl, which resembles a wooden sword with obsidian blades protruding from either side.  

The researchers determined that Stegouros is closely related to two other ankylosaurs from Australia and Antarctica. The latter, which is known as Antarctopelta, features “enigmatic” bony plates that have perplexed scientists but which might be part of the same kind of macuahuitl used by Stegouros, Vargas says.  

The findings suggest that Stegouros “is not an invader from the north,” he says. “It is actually a lineage that has roots so deep in time it’s [from] when all continents were together.”

As Pangaea finished separating into Laurasia (present-day North America and Eurasia) and Gondwana (which would become South America and the remaining continents) in the late Jurassic, the more familiar ankylosaurs would come to dominate the northern continent while Stegouros and its relatives laid claim to the south. 

For their analysis, Vargas and his team only described a single Stegouros specimen. They plan to search for more complete skulls in the future that can be compared with those of the ankylosaurs from Antarctica and Australia. The findings also emphasize how little is still known about the evolutionary history of armored dinosaurs in the southern hemisphere, the researchers concluded.

“You can expect more surprises from the south,” Vargas says.

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In the 1960s, Australian coal miners stumbled across huge, bird-life footprints protruding from the ceiling of their subterranean work site in south-eastern Queensland. The marks, more than a foot long, belonged to a creature that trekked across swampy land around 250 million years ago. They sent paleontologists into a tizzy, who though the tracks belonged to a carnivorous dinosaur—a creature larger than any other predator of its time.

Some fossil experts across the globe had their doubts about the footprints coming from a predator, though. But they couldn’t quite disprove the carnivore idea because all they had access to was black and white photos and a drawing of the tracks. With 3D modeling technology today, researchers have been able to analyze the impressions further, and identify the mysterious creature as an herbivore from the group Prosauropoda.

[Related: Dinosaurs who stuck together, survived together]

“We can now make 3D models, 3D visualizations, and augmented reality so that we can get not only a clearer and more detailed understanding of the fossil that we’re examining, but also communicate that in a more complete manner,” says Anthony Romilio, paleontologist at University of Queensland and lead author on the new study published in Historical Biology. He and his team used casts of one of the prints, made by geologists and the Queensland Museum back in 1964, to create a 3D model of the dinosaur’s foot to better understand it’s entire body.

Once the track was digitized, the researchers took exact measurements from the cast and verified them with the 3D model. Back in the ‘60s, scientists had to pull estimates from the single drawing and photos; their estimates put the the print as several centimeters longer than its actual length. Without certainty of the size of the print, it’s difficult to gauge the true nature of a long-extinct dinosaur.

Using the updated dimensions, and his colleagues multiplied the length of the dinosaur’s foot by a factor of four, which gave them the rough length of the leg up the hip joint. Smaller feet mean smaller legs, helping to create a picture of the entire dinosaur that indicated it was not a predator.

Even before he knew the proper size of the creature’s feet, however, Romilio had doubts about its supposed predatory behavior. Had it been a carnivore, it would have been the biggest predator of the Triassic period—which explains all the hubbub around the discovery decades ago. But other fossil finds show that dinosaurs of the previously estimated size didn’t turn up until millions of years later during the Jurassic period.

By distilling a 3D model of the track, Romilio and his team were able to make the original discovery more accessible to paleontologists across the world. Romilio also created an augmented reality visual of the dinosaur and its footprints, so that everyone, not just researchers, could see this creature on their iPhones and iPads. 

“This allowed a more comprehensive discussion about these footprints,” says Hendrick Klein, an expert on Triassic dinosaurs at the Saurierwelt Paläontologisches Museum in Germany. Romilio reached out to him for a second opinion after the study team realized the exact measurement of the foot came from a dinosaur that was smaller than imagined. Once Klein was involved, he corroborated the idea by looking at the Australian tracks against that of other Triassic herbivores.

“I remember that I had excavated footprints in North America, and had also seen similar footprints in Italy,” Klein says. “I compared Anthony’s results with these footprints, and what I distinctly saw was that they share similar morphology.” 

One particular feature Klein noted was the rotation of the print. The track is directed strongly towards the midline of this creature’s foot, indicating that the dinosaur’s steps rotate inwards, a feature that isn’t typically seen among predatory dinosaurs. 

Klein and Anthony both stress that prehistoric footprints are vital to understanding the fossil record. No one has identified skeletal dinosaur remains from the Triassic period in Australia yet, so researchers only have these small indications of life to better understand the continent’s past. They just have to get the math right; 3D tech will help.

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During the early Jurassic Period, some 200 million years ago, the only large herbivores in many ecosystems were long-necked dinosaurs called sauropodomorphs. These reptiles were the forerunners of the gargantuan sauropods, the group that included Brachiosaurus and Brontosaurus.

A well-populated breeding ground in southern Patagonia hints at one reason early sauropodomorphs were so successful: They knew how to stick together. When scientists analyzed the eggs and skeletal remains of juveniles and adults of a species known as Mussaurus patagonicus, they found that the fossils were segregated by age, suggesting that the dinosaurs raised their young as a community. 

The 193-million-year-old site represents the earliest evidence of herd-living in dinosaurs, the team reported on October 21 in Scientific Reports.

“People have known for a long time that the more advanced dinosaurs, the ones that lived in the late Jurassic and Cretaceous, especially the large sauropods…moved and lived in herds,” says Jahandar Ramezani, a geochronologist at MIT and coauthor of the findings. “But the question has always been, when did this behavior start?”

The species that he and his colleagues investigated was originally discovered in Argentina’s Laguna Colorada Formation in the 1970’s. In recent years, the team has excavated dozens more Mussaurus specimens of all ages from the site. The youngsters appear to have walked on four legs before becoming bipedal as they matured. The largest adult specimen would have reached an estimated 1504.8 kilograms (about 1.7 tons) in size.

In total, the researchers examined more than 100 eggs and 80 Mussaurus skeletons from an area of about 1 square kilometer (about 0.39 square miles). The team used x-ray imaging to peer inside the eggs and confirm the embryos’ identities. To determine the juvenile dinosaurs’ ages, the researchers counted the annual growth rings visible in fine slices of leg bone under the microscope.

The fossils were found close together, in three levels within an area of reddish-brown siltstone that appears to have been a shared breeding ground, Ramezani says. He and his colleagues observed that many of the fossils were grouped by age, including several nests with clusters of eight to 30 eggs, a collection of 11 juveniles that were the same size and appeared to have died and been buried together, and adults alone or in pairs.

[Related: This Australian behemoth is officially the largest dinosaur on the continent]

“This age segregation is basically key; it tells us that this is not something like a simple family structure, being parents and juveniles together,” Ramezani says. “These are colonies of a lot of dinosaurs that are basically taking care of the young [and] the eggs together.”

The sediments found amongst the fossils indicate that the site was located near a short-lived lake, he says. The researchers speculate that the dinosaurs might have died after a long drought, then been rapidly buried in windblown dust.

Mixed in with this dust there was also some volcanic ash, which contains minute zircon crystals. These crystals have high levels of uranium that over time decays into lead. By analyzing the amounts of both elements in the crystals, Ramezani and his team were able to calculate the age of the sediments the dinosaurs were buried in. They found that the site was 193 million years old, pushing back the earliest recorded herding behavior in dinosaurs by at least 40 million years. 

However, it’s likely that dinosaurs began gathering in herds to forage and care for young together even before Mussaurus appeared on the scene. This strategy may have enabled sauropodomorphs and possibly other early dinosaurs to thrive and eventually dominate ancient ecosystems, Ramezani says. 

In fact, paleontologists have reported nesting colonies of other early sauropodomorphs from China and South Africa that appear to have lived around the same time. 

“They have some ideas based on the rocks what the approximate ages would be, but they don’t have the exact ages,” Ramezani says. “We definitely need more information, better [estimates of] ages, to be able to put these pieces of the puzzle together and complete the picture of this social behavior.” 

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When it comes to snakes, the modern world offers an embarrassment of riches. There are almost 4,000 different snake species alive today, placing the group not far behind mammals in terms of diversity. The snakes are also varied in the types of food they prefer to consume: Some feast only on earthworms, while others can swallow an entire deer. 

“T​​hey just have an astounding variety of diets,” says Michael Grundler, a postdoctoral researcher in ecology and evolutionary biology at the University of California, Los Angeles. He and his colleague Daniel Rabosky, of the University of Michigan, wanted to know how this group became so diverse and successful. 

When they analyzed both the diets and the evolutionary relationships amongst hundreds of present-day snakes, the pair found that the mass extinction that finished off the dinosaurs was a game-changer for the limbless reptiles. Early snakes slithered into newly vacant ecological niches and rapidly evolved the ability to go after a wide array of prey, the scientists reported on October 14 in the journal PLOS Biology.

Little is known about the earliest chapters of snake evolution because the animals are rarely preserved as fossils, Grundler says. So he and Rabosky used information from living species to probe their history. They gathered more than 34,000 reports of the diets of 882 species based on observations of wild snakes and dissected museum specimens. The researchers also drew upon family trees determined from the genetics of modern snakes.

“With those two pieces of information we can make inferences about what extinct species might have looked like long ago,” Grundler says. The team used mathematical models to reconstruct how quickly these ancestral snakes might have changed through time as their diets shifted.

The earliest snakes were probably insect-eaters. However, by the time the dinosaur-killing asteroid arrived 66 million years ago, they’d branched out a bit to dine on vertebrate prey.

“Shortly after that event we find a signal of a big explosion in dietary diversity,” Grundler says. “The survivors of that event went on to evolve this huge range of eating styles that we see today.”

After this burst of activity, many groups also changed their diets very quickly when they journeyed to new locations. One particularly striking example is the dipsadine snakes, a subfamily with more than 700 species that include hognose snakes and false coral snakes. After arriving in South America, “They just exploded in their dietary diversity in a relatively short period of time,” Grundler says. “They evolved to specialize on earthworms, fishes, frogs, slugs, eels—even other snakes.”

[Related: These snakes wiggle up smooth poles by turning their bodies into ‘lassoes’]

On the other hand, some groups of snakes evolved far more slowly. Blind snakes, which feed mainly on colonial insects like ants and termites, appear to have had similar diets for tens of millions of years, Grundler says. 

The findings highlight how opportunities such as the disappearance of hungry competitors (and the rise of rodents and other delicacies) and moving into new habitats “shape evolutionary fortunes,” he adds.

For snakes, this led to a spectacular collection of adaptations for dining on mammals, birds, fish, amphibians, other reptiles, and a host of invertebrates. The emergence of venom allowed vipers and other ambitious snakes to bring down prey that might otherwise be too dangerous for them to subdue. 

There were also more unusual developments; members of the Pareinae subfamily in southeast Asia that dine exclusively on snails have more teeth on one side of their jaw than the other. This makes it easier for the snakes to “get in and rake the body of the snail” to extract the hapless animal from its asymmetrical shell, Grundler says.

At the same time, he and Rabosky observed, even snakes that are apparently specialized for one kind of prey have been known to gobble up other animals that come their way. This capacity for adventurous eating may have helped early snakes innovate and thrive throughout their history. 

While the new analysis covers all the major snake families, Grundler says, it only includes around a quarter of known species. “There’s thousands of species of snakes for which we know very little,” he says. “We still have a long way to go.” 

The next step will be to gather more information about these mysterious snakes and search for more information from the remains of their extinct relatives.

“This [work] all relies on living species,” Grundler says. “If we’re able to get better observations of diets of fossil snakes and include those in our analysis, that would be really important to do.”

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What do you think something called a hell heron might look like? Herons living today are necky, leggy birds with needle-sharp beaks. You might imagine an infernal version of this creature could also have horns or breathe fire. But in truth, it was a dinosaur with crocodile teeth. At least that’s what scientists have determined after a recent discovery of fossilized remains on the British Isle of Wight.

The hell heron is actually one of two new dinosaur species found, both from the family Spinosauridae, making these creatures spinosaurids, or spined dinosaurs. The new findings were published Wednesday in the journal Scientific Reports.

“Spinosaurs are cool,” says Neil Gostling, an evolutionary biologist at the University of Southampton who oversaw the fossil analysis. “I don’t normally use terms like ‘cool’ because I’m not cool enough to use terms like ‘cool.’” If a person who typically avoids using “cool” describes a dinosaur that way, this dinosaur must be pretty rad.

One thing that makes them so wicked awesome is that these specific Baryonyx were Frankenstein-esque terrestrial theropods, with nearly 30-foot-long bodies similar to a T. rex, but 3-foot-long heads more like crocodiles. Their narrow snouts and sharp, curved teeth could’ve been a dead ringer for the domes of the more familiar Australian terrors, though the two species are not directly related. 

[Related: What would a dinosaur taste like?]

While these spinosaurs lived on land, they were unusual in that they were probably aquatic hunters who skulked for fish in rivers. That’s where the “heron” part comes from: Scientists believe they would strike for fish much in the way that modern herons hunt. 

The hell heron has been specified as Ceratosuchops inferodios, which translates to “horned crocodile-faced hell heron.” The other is called Riparovenator milnerae, which means “Milner’s riverbank hunter,” in honor of the late British paleontologist Angela Milner.

Neither Gostling nor his team found the fossils; instead, they were discovered and donated by two fossil collectors, Brian Foster and Jeremy Lockwood, who donated their loot to the Dinosaur Isle museum. According to Gostling, the Isle of Wight is the best place in Europe to find dinosaur fossils, and one of the top ten places in the world, partially because the isle is eroding. 

As for the new fossils themselves, Gostling and his team were working with two early Cretaceous-era finds from about 125 million years ago. One is a part of the snout at the front of the face, and the other is part of the skull case. They’ve got 50 other parts of the jaw to work with, so they’ve been able to recreate approximately what one of these two dinosaurs looked like.

Gostling says that while these dinosaurs are similar, he’s uncertain they lived at the same time;  they could have been separated by a million years, in fact.

While these finds might not overturn any one aspect of paleobiology, Gostling says that at the very least more experts have their eye on spinosaurids because of them. This fossil analysis also yields a migratory map.

“We can see from our analysis is that spinosaurs originate in Europe, and then migrate into South America, into Asia and, into Africa,” says Gostling. “That’s the really exciting thing we’ve got, the answers to geography questions as well as trying to address the ecology in terms of the diversity of animals. “

Correction 10/5/2021: This article previously misidentified the hell heron as being from the genus Baryonyx. It is a Baryonchine spinosaur, but not of that genus.

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Movies like Jurassic Park may give the impression that we know everything about dinosaurs, including how they used to walk or run. But it’s actually incredibly difficult to figure out how extinct creatures moved their bodies. 

Now, a fruitful combination of computational biomechanics and so-called “predictive simulation” are helping fill in these locomotive knowledge gaps.  

To replicate the movements of a Triassic dino that lived around 200 million years ago, Coelophysis bauri, a team of researchers with diverse expertise developed a novel 3D simulation program. According to their results, small, two-legged dinosaurs like C. bauri likely swung their tails as they walked or ran—similar to how humans swing their arms. They reproduced how different muscles would interact, and looked at how C. bauri’s gait and momentum would have been impacted by tail movements. 

The tail, it turned out, regulated angular momentum and efficiency, reducing the muscular strain on the dinosaur’s body. The team believes this mechanism likely applied to other dinosaurs as well. The research was published in Science Advances.

Previously, paleontologists mostly believed that the tail was just a passive counterbalance that offset the weight of dinosaurs’ heads and necks, evolutionary biomechanist and co-author Peter Bishop told Live Science. “We didn’t really have expectations or hypotheses leading into this,” he added. “We assumed that [the tail] would just be there hanging.”

[Related: What would a dinosaur taste like?]

To make sure their model was consistent with real-life biomechanics, the team first used it to simulate birds called tinamous, elegant Central and South American avians with anatomy similar to bipedal dinosaurs. When they were sure that their simulation could faithfully replicate the bird’s bodily movements in real life, they turned their model to the C. bauri dinosaur. 

To really get at the tail’s importance, the team repeated the simulation, but removed the dino’s tail from the model. The simulated C. bauri had to move its pelvis differently. “When we chopped the tail off, the dinosaur was effectively having to wag its hips to compensate for the loss of the tail,” Bishop told The Guardian.

The tailless dino also had to increase its muscle effort by 18 percent, which suggests that the tail also helped keep energy expenditure low. When the team repeated the model and forced the tail out of sync, C. bauri again had to really up its energy use to travel at the same speed. 

“It’s always good to see robust computational biomechanics approaches applied to dinosaur locomotion,” said Nizar Ibrahim, a vertebrate paleontologist at the University of Portsmouth who is unaffiliated with the recent research, to Gizmodo. Ibrahim was the lead author of a study published in Nature last year that showed how one giant dinosaur, Spinosaurus aegyptiacus, may have used its tail to help it swim. He added that new work like this 3D simulation is adding to a growing body of research supporting the idea that “dinosaur tails were more dynamic and complex than previously assumed.”

Now that they have this simulation at the ready, Bishop hopes to apply it to all kinds of creatures of yore. “We are now primed to explore locomotion and other behaviors in a whole host of other extinct critters, and not just dinosaurs,” Bishop told Gizmodo. “Pretty much anything is fair game.”

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Unless someone finds well-preserved dinosaur DNA and decides to breed, say, free-range Velociraptors in an agricultural twist on the standard Jurassic Park scenario, we’re probably not ever going to taste the flesh of the roughly 700 species of extinct dinos. But we can hypothesize, and the answer is a lot more complicated than “dinosaurs probably tasted like chicken.”

Let’s get one thing out of the way first: If you’ve eaten any type of bird, you’ve eaten dinosaur. Modern birds are the last living therapods—the same group of animals that includes Tyrannosaurus rex and Velociraptor—so they’re not simply “descended from” dinosaurs, they are dinosaurs.

So yes, chicken (a dinosaur) tastes like chicken. Crocodilians (like alligators), which share a common ancestor with dinosaurs, also kind of taste like chicken. And that’s a good starting point when you’re thinking about what Stegosaurus or Compsagnathus might’ve tasted like.

“In evolutionary biology terms, there is an extant phylogenetic bracket of chicken-tasting animals—crocs and birds—surrounding the dinosaurs on the family tree, making it reasonable that the dinosaurs had a chicken taste too,” says Steve Brusatte, a paleontologist and professor at the University of Edinburgh.

But it’s not that simple. Every bird has a unique taste. If you’ve eaten duck in the US, it was probably the American Pekin, a domesticated mallard with a mild, somewhat gamey taste. Merganser, another type of duck, is quite fishy and some people find it unpalatable. Extinct dinosaurs likely had similarly varied flavor profiles.

There are also countless factors that go into making something taste the way it does, but two of the most important are muscle usage and diet.

Triceratops and Allosaurus likely had fast- and slow-twitch muscles like people and other animals do. Slow-twitch fibers are associated with dark meat—thanks to reddish hues linked to the oxygen-carrying protein myoglobin—while fast-twitch fibers are associated with white meat.

Smaller predatory dinosaurs probably had to move quickly to ambush prey and dart away from threats, so they might’ve had a fair amount of white meat. Velociraptor may have truly tasted like chicken. Larger dinos, on the other hand, likely had large muscles that were constantly moving and needed a lot of oxygen, so they might’ve more closely resembled beef or venison.

Animals can also take on the flavor of things they eat. Grass-fed beef can be a bit more earthy than corn-fed cattle, for example. Dinosaurs, however, probably didn’t eat much grass, as it didn’t evolve until the very end of their 165 million-year reign. Therapods had a varied diet, while herbivores chowed down on ferns, cycads, and conifers, to name some ancient plants that are still around today.

Today, deer eat a similar diet, so some dinosaurs could’ve tasted like venison. They also may have been gag-inducing—the spruce grouse, a chicken-like bird, spends its winters munching almost exclusively on conifer needles. If you eat one at that time, it can taste heavily of spruce, almost like turpentine, says Hank Shaw, a chef and outdoorsman who specializes in wild foods.

Ultimately, there’s no definitive answer for what extinct dinosaurs might’ve tasted like, but we can let our imaginations run wild. And if someone ever does acquire the ability to bring dinosaurs back from extinction, we’d do well to remember that the Jurassic Park movies don’t end with people eating their creations—more often, it’s the other way around.

Is your head constantly spinning with outlandish, mind-burning questions? If you’ve ever wondered what the universe is made of, what would happen if you fell into a black hole, or even why not everyone can touch their toes, then you should be sure to listen and subscribe to Ask Us Anything, a brand new podcast from the editors of Popular Science. Ask Us Anything hits Apple, Anchor, Spotify, and everywhere else you listen to podcasts every Tuesday and Thursday. Each episode takes a deep dive into a single query we know you’ll want to stick around for.

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Rising out from the Kyzylkum Desert of Uzbekistan is the Bissekty Formation, a structure of rock and sediment between 90 and 92 million years old that has preserved many a dinosaur fossil. Out of this formation, paleontologists have discovered an imposing new dinosaur species that was likely the apex predator of the area at the time.

The discovery, Ulughbegsaurus uzbekistanensis, was a carcharodontosaur, or a “shark-toothed” dinosaur, a kind of allosaur characterized by its large size and serrated teeth. It’s the first of its kind to be found in Central Asia. And while paleontologists only had a single fossil to work with—a part of the dino’s upper jaw—researchers have concluded that this specimen likely measured around 26 feet (8 meters) in length and weighed about 2,200 pounds (1,000 kilograms). 

Those massive dimensions means that U. uzbekistanensis was twice the length and more than five times heavier than the predator previously thought to be the apex of the area, the tyrannosaur Timurlengia, which measured 13 feet (4 meters) in length and weighed in at 375 pounds (170 kilograms). The findings were published in Royal Society Open Science.

[Related: The real Jurassic Park may have been in the Arctic]

“The skull would have measured about a meter. It had knife-like, sharp teeth and was a meat-eater,” lead researcher of the study, paleontologist Kohei Tanaka, told Express. 

University of Minnesota paleontologist Peter Makovicky, who was not involved in the study, agreed with the paper that U. uzbekistanensis was likely at the top of the local food chain. “I think this bone is so big that this would have been a very large predatory dinosaur and very likely the apex predator in its ecosystem,” he told Live Science. 

The giant jawbone was found in Uzbekistan in the 1980s, but researchers rediscovered the fossil when looking through the collection of an Uzbekistan museum. Senior author and Hokkaido University Museum paleontologist Yoshitsugu Kobayashi explained in a statement the value of this finding: “The discovery of Ulughbegsaurus uzbekistanensis fills an important gap in the fossil record, revealing that carcharodontosaurians were widespread across the continent from Europe to East Asia.” 

The study authors also write that, sometime before the Late Cretaceous period (between 66 and 100 million years ago), carcharodontosaurians like Ulughbegsaurus disappeared from Central Asia, ceding that top predator spot to tyrannosaurs. But a scarcity in research and fossil discovery means that not a lot is known about this transition. U. uzbekistanensis is now the latest known carcharodontosaur known to coexist with tyrannosaurs in this time period. 

“For many tens of millions of years, tyrannosaurs were the understudies of the allosauroids,” University of Edinburgh paleontologist Stephen Brusatte, who was not involved in the new research, told Smithsonian Magazine. “Allosauroid” refers to the larger family that carcharodontosaurians like Ulughbegsaurus belonged to.

Though it’s clear that tyrannosaurs took over the area as carcharodontosaurs disappeared, it’s still unclear why, and new fossils like this can help illuminate the question: “Given that allosauroids were holding back tyrannosaurs for so many tens of millions of years, I can’t envision that tyrannosaurs suddenly figured out how to out-compete [them],” Brusatte said. Having this new fossil, therefore, is a great new piece of the puzzle to have: “This is one new bone, and really just part of a bone, but its importance far eclipses its looks.”

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In the central Chinese province of Henan, a farmer discovered a black orb with a vaguely blue tint, about the size of a billiards ball. While he and initial researchers thought they had found a dinosaur egg, it turned out to be something much rarer: a huge fossilized turtle egg—with an intact turtle embryo still inside. 

The biggest turtle eggs today are just a few inches long, with papery thin shells. The newfound fossil is massive by comparison. Paleontologists concluded that the egg belongs to the nanhsiungchelyids, an extinct group of land-dwelling turtles that lived alongside dinosaurs 145 to 66 million years ago, during the Cretaceous period. The turtle parent who laid the hefty egg was likely quite the beast—researchers estimate that its shell was more than 5 feet and 4 inches long. The new paper was published today in the Proceedings of the Royal Society B. 

“This is actually the first time that [fossil] turtle eggs or a nest really could be attributed to a particular turtle,” Darla Zelenitsky, a co-author of the study and a paleontologist at the University of Calgary, told CBC. She added that the egg could have been entombed when a nearby river system overflowed during the rainy season, thus preserving it as a fossil. 

[Related: We may finally know where young turtles spend their ‘lost years’]

The physiology of the ancient embryo is surprisingly similar to those of modern turtles. Raul Diaz, a reptile evolutionary biologist specializing in embryos at California State University at Los Angeles who was not part of the study, told National Geographic that the specimen’s bone structure is more or less what you’d expect to see today. “It’s almost—in my head—indistinguishable from what I would see in the lab.”

While the fact that turtles and dinosaurs once roamed side by side is well-established, the rarity of fossilized eggs (let alone with intact embryos) means that very little is known about the animals’ nesting practices. This egg, and its robustness, give paleontologists more clues.

The nanhsiungchelyid turtle shell is four times thicker than those of the biggest Galapagos tortoises today. That thickness may have been an adaptation to keep embryos safe in a hot and dry climate, or as a way to prevent breakage when the eggs were buried under mounds of wet soil. 

It also bolsters the theory that these turtles spent all their time on land, Jordan Mallon, a paleontologist at the Canadian Museum of Nature in Ottawa not involved in the research, told CBC. He added that this has been debated for some time, and that the techniques in the study could later be used to answer lingering questions about the evolution of turtles, for example how their shell characteristics have changed over the millennia.

These turtles’ land-based lifestyle may have also been their undoing. The nanhsiungchelyids were wiped out approximately 66 million years ago by the same fated asteroid that killed the dinosaurs. Other more aquatically-inclined turtles survived the blast, perhaps shielded by their underwater dwellings. Whether that’s the whole story remains to be seen, but after the Cretaceous period, nanhsiungchelyid turtle shells disappeared from the fossil record, never to be seen again.

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Paleontologists have discovered three new early mammal species that dwelled in present-day Wyoming shortly after the dinosaurs went extinct, suggesting that this early chapter in the dawn of mammals was more diverse than previously recognized. 

The researchers examined the fossilized teeth and jaws of the mammals, which were about the size of a giant rodent or small cat. They found that they belonged to a group called condylarths, or archaic ungulates, which includes the ancestors of today’s hooved animals. These specimens lived within the first 328,000 or so years after the dinosaurs disappeared, a time known as the early Puercan age.

Most sites in the western United States and Canada with fossils from this period contain largely the same few mammal species, says Jaelyn Eberle, a curator at the University of Colorado Museum of Natural History in Boulder. She and her colleague Madelaine Atteberry reported the new findings on August 18 in the Journal of Systematic Palaeontology. 

“Here we have one [site] where there’s a bunch of new guys on the scene,” Eberle says. “The diversification of mammals occurred, or certainly started, sooner than what we would predict from looking at other areas.”

After a massive asteroid struck Mexico’s Yucatán Peninsula about 66 million years ago, many mammals went extinct along with the dinosaurs. Those that remained would generally have been the size of mice or rats. The most abundant group of mammals in North America during this time was the condylarths. Their fossilized teeth don’t appear to be specialized for dining on flesh or plants, and they may have been omnivores.

The condylarth teeth that Eberle and Atteberry examined had previously been collected from a sandstone river channel in a quarry in south-central Wyoming’s Great Divide Basin. Teeth are hard and plentiful, meaning they are preserved well as fossils, and their bumps and ridges can be used to identify both present-day and ancient mammals. 

When the researchers examined the specimens’ teeth and jaws, they found distinctive features suggesting they were looking at three previously unrecognized species. To find out where these creatures fell in the ungulate family tree, the team compared the fossils to teeth from 25 other condylarths and another more distantly-related early mammal. They analyzed 64 characteristics of each specimen’s teeth and used a computer program to determine how closely related their mammalian owners were. 

This analysis confirmed that the three new species fell within a family called the periptychids. This family had bulbous cheek teeth, in some cases with striated enamel that would have strengthened the tooth and perhaps enabled the animal to eat hard materials such as seeds.

[Related: This Australian behemoth is officially the largest dinosaur on the continent]

One of the new species was stuck out. Beornus honeyi would have been roughly the size of a housecat and had strikingly large striated cheek teeth. (Its name is a reference to Beorn, a character from J.R.R. Tolkien’s The Hobbit, and who is known for his massive size.)

“Periptychids all have these puffy teeth, but Beornus is above and beyond,” says Atteberry, a geologist and undergraduate program assistant at the University of Colorado Boulder. “They look like they were stung by little bees; they’re very swollen-looking.” 

The other new species were likely between a rat and housecat in size. Miniconus jeanninae was distinguished by an unusual extra cusp on its molars. Conacodon hettingeri is set apart from its close relatives by several features, including a comparatively short lobe on its last molar.   

While the three species boasted distinct dentition and probably had somewhat different diets, it’s not clear what they actually did eat from the shape of their teeth alone, Eberle says. Part of the reason for this is that condylarth teeth don’t generally resemble those of any living mammals. In the future, Eberle and her colleagues hope to build a better picture of what the mammals might have feasted on by looking at wear patterns on the teeth, such as little pits and scratches that would indicate that an animal had dined on seeds or other crunchy things.

The specimens Eberle and Atteberry investigated were housed in the University of Colorado Museum of Natural History, along with more than 400 others from the same site. 

“I would predict that there’s a number of new species still yet [to be identified] in the collection that we need to get studying,” Eberle says. “This is just the beginning.”

The new findings highlight how quickly mammals began to bounce back after the cataclysmic asteroid strike, says Nick Longrich, a paleontologist at the University of Bath in England who was not involved with the research. 

These early mammals would have faced little competition and evolved to fill ecological roles vacated by the dinosaurs. “You’re seeing this incredible burst of creativity of the mammals, kind of in response to this disaster,” Longrich says. “It doesn’t surprise me at all that there’s much more happening much faster than we thought.”

The discovery of three new species not seen anywhere else also demonstrates how different locations might have developed unique pockets of diversity.

“It’s not a monotonous wasteland but a sort of diverse set of post-apocalyptic landscapes,” Longrich noted in an email. “Imagine if, for example after the world ends, it’s a zombie apocalypse in one area, Mad Max bikers in another region, cannibal cult in another, and so on.”

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A new species of pterosaur has been discovered, a flying reptile that once graced the skies of the Australian Outback around 105 million years ago. The imposing, dragon-like creature, Thapunngaka shawi, was named to reflect its extremely pointy teeth in the now-extinct language of the local Indigenous Wanamara tribe. 

In 2011, a local fossil hunter discovered a portion of what looked to be a lower jaw. Upon examination, paleontologists realized that this was a new, rather impressive species of Australian pterosaur. Their analysis showed that this winged reptile must have had a skull longer than three feet, and a wingspan of about 30, making it the largest Australian pterosaur discovered to date. They published their findings in the Journal of Vertebrate Paleontology. 

Before University of Queensland paleontologist and lead author Tim Richards properly examined Thapunngaka shawi, the fossil stayed on display in Kronosaurus Korner, a local museum. “It had a sign on it which just said ‘Pterosaur – indeterminate,’” Richards told Brisbane Times. But “I realized once I started looking at it closely that it had features I’d never seen before and I wondered if it could be something new,” he added. “Lo and behold, it was.”

[Related: This Australian behemoth is officially the largest dinosaur on the continent]

While Australia has been the site of many dinosaur discoveries, it’s still fairly new to the pterosaur game, which represents a branch of prehistoric animals related to but still distinct from dinos. The continent’s first specimen was discovered just 40 years ago, and only 20 specimens have been identified to date. Richards told Australia’s ABC News that “by world standards, the Australian pterosaur record is poor but the discovery of Thapunngaka contributes greatly to our understanding of Australian pterosaur diversity.”

Although Thapunngaka shawi’s 30-foot wingspan is nothing to scoff at, it’s certainly not the largest pterosaur to have ever lived on Earth. The Transylvanian “Dracula” pterosaur, which lived between 240 and 66 million years ago, had a wingspan of almost 40 feet. A Texan pterosaur discovered in the 1970s had an estimated wingspan of more than 50 feet. 

A new pterosaur discovery is exciting because “it’s the closest thing we have to a real-life dragon,” said Richards in a statement. They were “a successful and diverse group of reptiles—the very first back-boned animals to take a stab at powered flight.”

And Thapunngaka shawi was definitely a fearsome predator. “It was essentially just a skull with a long neck, bolted on a pair of long wings,” Richards added. “This thing would have been quite savage. It would have cast a great shadow over some quivering little dinosaur that wouldn’t have heard it until it was too late.”

In naming their new pterosaur species, the researchers wanted to honor the local First Nations Wanamara people. The word “thapunngaka” combines thapun [ta-boon] and ngaka [nga-ga], which are Wanamara for “spear” and “mouth,” respectively. “Shawi” is taken from the name of the fossil’s discoverer, Len Shaw. Together, the species name means “Shaw’s spear mouth.”

Correction 8/10/2021: Due to an editing error, a previous headline for this story named the species as a dinosaur, when, in fact, it is an ancient reptile.

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A remarkably preserved skull from a small, gull-like creature called Ichthyornis may shed light on how the ancestors of modern birds weathered the mass extinction that killed off all the other dinosaurs. 

Scientists compared the Ichthyornisin skull to those of dozens of living birds. They found that this close relative of today’s birds nonetheless had a brain whose shape was distinctly different. The findings indicate that the expanded forebrains found among living birds helped them adapt to a rapidly changing world, the researchers reported on July 30 in Science Advances.

“A unique brain shape, specifically a really large cerebral hemisphere, was a major factor in why living birds were able to survive when no other dinosaurs could,” says Christopher Torres, a paleontologist at Ohio University in Athens and coauthor of the findings.

When an asteroid more than six miles wide smashed into Mexico’s Yucatán Peninsula 66 million years ago, it triggered tsunamis and wildfire and kicked up a blanket of dust that circled the planet and blocked the sun’s light, causing plants to die and dramatically altering Earth’s climate. Yet some ancient birds survived the catastrophe, and scientists have proposed several ideas about which traits might have given them an edge. 

[Related: This Australian behemoth is officially the largest dinosaur on the continent]

One possibility is that these birds were smaller, and thus more adaptable, than their neighbors. “How much food an organism needs to eat, how it can travel, where in the world it can live, what latitude it can live at, all of these traits are linked to body size,” Torres says.

Or perhaps the answer lies in the toothless beaks seen in today’s birds, which could dine on a range of foods, from flesh to seeds. 

Present-day birds also have very complex brains. “They’re incredibly smart creatures, and so it’s been proposed that some aspect of the brain and what the brain can do may have contributed to that unique survivorship,” Torres says.

Unfortunately, though, very little is known about the brains of early birds. As a group, they are relatively small and have fragile bones. The process of fossilization is “unimaginably brutal,” Torres notes, and the few skulls that withstand it tend to wind up flattened and difficult to decipher. 

But Archaeopteryx, the earliest recognized bird which lived 150 million years ago, is an exception. Scientists have been able to determine that its forebrain was proportionately much smaller than those of living birds. 

The 70-million-year-old Ichthyornis skull Torres and his colleagues examined may fill in some of the gaps between Archaeopteryx and living birds. Ichthyornis was a pigeon-sized seabird with a toothed beak that dwelled in present-day North America. It’s also one of the closest-known relatives of living birds. This means Ichthyornis can help researchers narrow down which traits were truly unique to the bird lineages that survived the asteroid’s aftermath. 

Torres and his team used CT scans of the nearly complete skull, originally discovered several years ago by collectors in Kansas, to digitally reconstruct the general shape of Ichthyornis’s brain. The researchers then compared this brain to similar analyses of Archaeopteryx, several more distantly-related dinosaurs, and dozens of living birds including flamingoes, woodpeckers, penguins, ostriches, and robins. 

In living birds the cerebrum, a part of the forebrain made up of a left and right cerebral hemisphere, is very large relative to the rest of the brain. This region is where higher cognition occurs, including the processing of sensory information, memory, and more. 

To accommodate its impressive size, the cerebrum is also positioned differently in birds compared with other reptiles such as snakes and crocodiles. Modern birds have a cerebrum that sits atop, rather than directly in front of, the midbrain.

Torres and his colleagues found that Ichthyornis, despite its evolutionary proximity to living birds, had a brain that was much more similar to that of Archaeopteryx. Its cerebrum was still fairly small and its brain had an overall more linear shape. The bulky cerebrum, the results suggest, didn’t become really pronounced until the modern birds emerged. 

It’s not clear precisely what advantages these expanded forebrains gave these birds, Torres says. However, as conditions deteriorated in the wake of the asteroid, he says, “their ability to process those changes and react accordingly, and quickly enough, could have made all the difference when it came to surviving this mass extinction event.”

That said, brain size probably wasn’t the only reason that the ancestors of today’s birds survived. Their small bodies, beaks, and other traits may have also contributed, Torres says. The researchers did attempt to estimate the impact of body size by analyzing measurements from more than 2,000 extinct and living species. However, they felt they didn’t have enough information on the body sizes of other birds that lived at that time to properly determine if size played a role in survival. 

Additionally, he cautions, the researchers could only draw upon data from the skulls of two ancient bird species.

“We still don’t know what the brain looked like in most early birds,” Torres says. He hopes that more well-preserved fossils like that of Ichthyornis will be unearthed in the future. “That’s really going to help us fine tune this picture and better understand what it is that made living birds so special.”

As a next step, the researchers will examine living birds to understand how much the cerebrum varies among members of the same species. This in turn will help determine how well the few available Ichthyornis and Archaeopteryx skulls actually represent these long-gone birds.

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Last week, researchers from Brazil published an article in the Journal of South American Earth Sciences updating the world on the state of dinosaur trace fossils in Brazil. But they’re not just any trace fossils; these are the fossilized remains of the remains of a dinosaur’s dinner: feces and urine.

Fossilized feces are called coprolites and are not uncommon. You can buy coprolite jewelry on Etsy and a (potentially mis-identified) six-million-year-old coprolite sold at auction for $10,370 earlier this year.

Unlike feces, liquid urine doesn’t get preserved for millions of years. But the impression of a high-powered stream of dinosaur pee hitting soft sand can be preserved. Those impressions are called urolites, and they look like this:

Urolites

Imagine you briefly turn on a hose and fire it at soft soil or sand. You’ll probably create a deeper hole where the water initially hits, and then a shallower, narrower, area as the liquid flows away. That’s the shape that these urolites have. When the researchers originally published a study on the Brazillian urolites back in 2004, they looked to a modern animal to explain their distinctive shape. It turns out that ostriches pee (video, if you are so inclined) in a similar way, letting out a stream of liquid waste that hits the ground at a fairly high speed, followed by their solid waste, separately.

It’s a fascinating idea, but scientists are still trying to figure out if that’s actually how dinosaurs pee.

“The question,” Brian Switek wrote on his Laelaps blog earlier this year “is whether non-avian dinosaurs expelled their solid and semi-solid waste together, like many birds, or they urinated and defecated separately as ostriches and crocodylians can.”

Figuring out how dinosaurs excreted their excrement still requires more research — and more fossils. But those aren’t easy to come by. The urolites in Brazil are among the few dinosaur-associated urolites in the world. The scientists in Brazil are concerned about the preservation of the coprolites and urolites, writing in their conclusions that their work collecting specimens is being hampered by mining and ranching operations near the location of the fossils, which they refer to as a “natural treasure.”

I think we can all agree that it’s a fairly impressive description for something that started out as… well… crap.

The post Fossilized In Brazil: The Impact From Dinosaur Urine On Sand appeared first on Popular Science.

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The 3-foot-long Microraptor, one of the smallest dinosaurs in the fossil record, had feathers on its arms, legs and tail. Its odd-looking five-wing gliding setup provides clues to the earliest evolution of flight, according to a new study in Nature Communications.

Dinosaur In The Wind

To figure out how exactly Microraptor might have flown, a team of scientists from the University of Southampton in the UK designed an anatomically accurate model and tested its abilities for stability and speed in a wind tunnel. The early Cretaceous dinosaur was a paravian–a classification of dinosaurs that were closer to birds than species like the T. Rex.

Studying The Evolution Of Flight

In the wind tunnel, the blue 3-D model of a Microraptor showed that the dinosaur probably would have flown down from the trees and glided slowly across medium distances. The dinosaur would have been most stable by generating a great deal of lift with its wings, but the exact positioning and angles of the wings, which haven’t been determined, didn’t make much of a difference–small changes in the shape and orientation of the wings and legs didn’t change how well the model flew. The researchers write that this suggests early fliers like Microraptor “did not require a sophisticated, ‘modern’ wing morphology to undertake effective glides.”

See part of the wind tunnel test in the video below:

The study is published in Nature Communications today.

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When you imagine a dinosaur’s habitat like that you would see in Jurassic Park, a hot and humid spot filled with verdant greenery might come to mind. However, a growing body of evidence points to these prehistoric reptiles romping around in much chillier climates—as far north as the Arctic.

Researchers discovered hundreds of teensy tiny baby dinosaur bones in Northern Alaska, suggesting polar dinosaurs lived in high latitudes year-round. They published their findings this month in Current Biology.

“It wasn’t long ago that people were surprised dinosaurs could live in the Arctic at all, and now we know they’re actually reproducing there,” Patrick Druckenmiller, lead author and director of the University of Alaska Museum of the North, says. “And that just has a whole bunch of mind-blowing consequences as far as how dinosaurs lived and what types of adaptation they had.”

Discovery of cold weather Cretaceous creatures

Researchers discovered the first fossilized remains of Arctic and Antarctic dinosaurs in the 1950s. Before then most paleontologists believed the environmental conditions—think months of darkness and snow—would have been too severe for reptiles to thrive in. 

Upon finding the frost-loving dinos, paleontologists put forth two explanations. The first posited the creatures spent their whole lives in the tundra. But a second theory predicted herbivorous dinosaurs migrated north as temperatures warmed and leafy-greens sprouted through thawing ground. Trailing their prey, carnivorous dinosaurs followed, and as wintry weather arrived, both herbivores and carnivores followed their food southward again.

To quite literally dig up the truth, Druckenmiller and his team spent three decades unearthing evidence at their field site in Northern Alaska. The fossil-rich spot, known as the Cretaceous Prince Creek Formation (PCF), is located along the bluffs of the Colville River as it merges with the Arctic ocean, and is one of the best locations in the world to study polar dinosaurs. 

To reach the paleontological goldmine in the depths of rural Alaska, the scientist spent three to five days traveling by car, helicopter, and boat. Then, they would pitch camp along the gravelly banks for three weeks. 

“This was really a labor of love,” Druckenmiller, who spent many a night wet, muddy, and blasted with freezing sea breeze, says.  

[Related: These ancient deep-sea fish can live five times as long as biologists expected]

Digging up baby dinos 

At the formation, the researcher found small bones—many of which were too tiny to belong to your ordinary small-bodied beast. 

“Once we started to see really small teeth and really small bones that showed features of very, very young animals it started to gradually dawn on us that maybe these aren’t just small species of dinosaurs, maybe these are babies,” Druckenmiller said. 

The researchers were soon re-filling their food buckets with pounds of sediment to bring back to the lab, where they would screen the sand through sieves. Every grain larger than half a millimeter under a microscope—that’s one-third the size of a pinhead—was closely inspected. 

What they discovered was thousands of teeth. When compared to similar dinosaurs from other parts of the world, they found the teensy teeth didn’t just belong to baby dinos. Some were so small they could only come from perinatal dinosaurs, those who die while still in the egg or just after hatching. They matched the pearly whites to a variety of both herbivorous and carnivorous species like duck-billed, horned, and dome-headed dinosaurs. Even fearsome tyrannosaurids had hatched amongst the snow. 

“We now understand that dinosaurs were not only living way up in the polar regions, which is remarkable in itself, but that they were also reproducing up there. And if they were reproducing up there, it strongly implies that they were spending their entire lives living in the arctic,” Druckenmiller said. 

The eggs of these bygone animals took two to six months, maybe even longer, to hatch. Therefore, if their mothers popped them out at the dawn of spring, the hatchlings only had a few months to grow before winter set in. Thus, a thousand mile migratory trek would be out of the question. 

Reimaging dinosaurs—and their habitats 

Knowing dinosaurs spent their whole lives at the poles means paleontologists have to reconfigure their understanding of them. 

In order to survive 120 days of continuous darkness and an average temperature of 43 degrees Fahrenheit, the circumpolar creatures were most likely warm-blooded. They could have even been decked out in fuzzy feathers like gigantic, ancient snowy owls to keep warm. 

“One idea is maybe dinosaurs hibernated,” Druckenmiller says, “and there’s no reason why we might not actually find something like a dinosaur borough that some of the smaller species may have snuggled up in for the winter.” 

Regardless, the findings conjure an alternate universe where down-covered dinosaurs scampered through snow-covered forests. 

“It just makes you realize what a different world it was 70 million years ago, that Alaska, which was even farther north at the time, supported forests, and in those forests were crazy dinosaurs running around, trying to struggle their way through winter,” Druckenmiller said. “It’s mind-blowing.”

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Allosaurus

For 165 million years, dinosaurs dominated land, sea, and sky. Long-necked Brachiosauruses lumbered along like mobile four-story buildings. Tyrannosaurus rex chased down prey with 50 to 60 teeth as big as bananas. Mosasaurs stretching 55 feet from snout to tail terrorized the seas, consuming everything they could catch.

But 66 million years ago, the world’s climate drastically changed. Dinosaurs had thrived in the warm temperatures and mild weather of the Mesozoic era. All of a sudden, the Earth became much colder and darker. Plants died and food became scarce. All the dinosaurs—except for the ancestors of modern birds—and three quarters of the creatures living on Earth went extinct.

To this day, scientists debate what caused this sudden change. The leading theories involve an asteroid strike and a giant volcano.

Both theories start with a rare metal called iridium. This element is extremely rare on our planet’s surface, but does exist in Earth’s liquid core and in space rocks like asteroids. In the rock underneath the Earth’s oceans and continents, there’s a thin iridium layer in what geologists call the K-T Boundary, or the point in the geologic record where they see evidence of the dinosaurs’ mass extinction.

Discovering this layer led scientists to speculate that a giant, six-mile-wide meteor hit the Earth around 66 million years ago. The impact had the force of 10 billion nuclear bombs and would have thrown massive clouds of iridium dust and other debris into the air, blocking out the sunlight for years.

Researchers discovered an enormous crater in the Yucatan Peninsula in Mexico that may have been in just the right spot to cause maximum destruction, as the rocks in this area may have been especially rich in carbon dioxide and sulfur or hydrocarbons, all of which could have been released into the air upon impact and contributed to the rapid shift in the climate. The crater was also around 66 million years old. Scientists found some other strange clues in the ancient layers: shocked quartz, rock that looks like a massive shockwave rearranged its crystals; soot that suggested widespread wildfires; and glass-like spheres that looked like cooled molten rock.

While many scientists think a giant fireball signaled the end for the dinosaurs, not everyone is convinced. Some say the iridium layer and the strange rock clues could also point to volcanic activity instead.

Volcanoes went wild during the last 40 million years of the dinosaurs’ reign. In what is now western India, giant cones belched lava drawn up from the Earth’s mantle, spewing dust and ash. After millions of years of eruptions, scientists reason there could have been enough debris in the air to block out the sun. The volcanoes also could have drawn iridium from deep within the Earth to form the thin layer we see in the crust today.

Some scientists argue the volcanoes would not have changed the climate drastically enough to kill all the dinosaurs. Others say the truth could be a combination of these two theories. The asteroid could even have made the eruptions worse, giving the dinosaurs a geologic one-two punch. Other scientists think the dinosaurs had already started gradually dying off before something catastrophic finished them off.

Whether by asteroid or volcano, we do know the whole planet changed suddenly and drastically. And when the darkness lifted, the surviving mammals, reptiles, and birds took over the planet.

This story has been updated to reflect the fact that the theorized impact of the asteroid collision was along the lines of 10 billion nuclear bombs, not 10 nuclear bombs, as previously stated. We regret the error.

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What was once thought to be the smallest dinosaur ever found has now been confirmed to be a lizard.

In March 2020, a Nature paper stirred some controversy when scientists identified a skull encased in 99 million year old Myanmar amber as that of a tiny, bird-like dinosaur. The authors dubbed the specimen Oculudentavis khaungraae, and acknowledged the strangeness of the fossil—most notably, they found the shape of the bones, especially around the eye region, didn’t seem to follow other bird or dinosaur evolutionary patterns.

Following publication, other paleontologists refuted the paper’s findings. Another team of scientists published a preprint in bioRxiv in June of 2020, stating that the skull more closely matched one of a lizard. The Nature paper was retracted in July of 2020. Released as a preprint in August 2020, and now as a fully peer-reviewed study in Current Biology, another study by a third team of scientists confirms that Oculudentavis is a lizard genus. 

The new paper is based on another, better preserved specimen—a fossil also from Myanmar, whose skull is about a half an inch long, and also around 99 million years old. Using CT scans and 3D remodeling, the authors concluded that their fossil was a different species in the same genus as O. khaungraae—they called their specimen Oculudentavis naga—and that both species were indeed strange lizards rather than small dinosaurs. 

“It’s a really weird animal. It’s unlike any other lizard we have today,” Sam Houston State University herpetologist and study co-author Juan Diego Daza said in a statement. He added that the Cretaceous Period, when these fossils were formed, was when many lizard and snake groups emerged, but “they still hadn’t evolved their modern appearance,” which explains why identifying these fossils can be so challenging. “That’s why they can trick us. They may have characteristics of this group or that one, but in reality, they don’t match perfectly.”

[Read more: This Australian behemoth is officially the largest dinosaur on the continent]

The way the amber fossils were preserved distorted the skulls of both Oculudentavis specimens, which contributed to the original misunderstanding. O. khaungraae’s snout was distorted into a narrower cone shape, giving a birdlike impression, while O. naga’s upper skull was likely flattened during fossilization to appear more lizard-like. 

The genus name Oculudentavis, established by the authors of the first Nature paper, means “eye tooth bird” in Latin. Even though that name is technically inaccurate now, Daza told CNN that taxonomic rules for naming and organizing animal species dictate that they have to continue using it. “Since Oculudentavis is the name originally used to describe this taxon, it has priority and we have to maintain it,” Daza said. “The taxonomy can be sometimes deceiving.”

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After 15 years of analysis, scientists have finally confirmed the discovery of Australia’s largest known dinosaur species. 

The first remnants of Australotitan cooperensis were found in 2006 near Eromanga in southwest Queensland, Australia, by Robyn Mackenzie, a paleontologist at the Eromanga Natural History museum, on her own property. She and her husband nicknamed the then-unknown dinosaur “Cooper,” after Cooper Creek near the discovery site. They then called in collaborators to complete the excavation. 

The team unearthed thousands of pounds of bones.

But just digging up the fossils wasn’t enough. The real investigation came after. Based on the bones they collected, the team suspected that this dino was a sauropod, a type of dinosaur previously found in the area (well known sauropods include the brontosaur and the brachiosaurus). But in order to identify just what species Cooper was, scientists needed to methodically compare their found bones to those of previously described species. 

“It’s taken this long because it’s such a painstaking piece of work, you’ve got to take the bones out of the ground, you’ve got to prepare the fossils, and then you’ve got to study them and compare them against all other species of dinosaurs worldwide,” Queensland Museum palaeontologist and co-author of the study Scott Hocknull told Australia’s ABC News.

Rather than cart cumbersome loads of fossils around the world, the team turned to 3D scanning technology for analysis. “[It] allowed us to virtually carry thousands of kilograms of dinosaur bones in one seven kilogram laptop,” Hocknull wrote in The Conversation. 

Not only did the researchers find that Cooper was not a member of any previously described species, they also officially deemed the Australotitan dinosaur, or the “southern titan,” to be the largest known dinosaur to ever roam the outback. It likely weighed somewhere between 25 and 81 tons. At about 80 to 100 feet long and 16 to 21 feet tall at its hip, Australotitan is also within the top 10 to 15 largest dinosaurs in the world. For comparison, the Tyrannosaurus rex was only about 40 feet long and 12 feet tall. 

With those stats, Cooper joins the ranks of the titanosaurs, a group of mega-beasts previously only discovered in South America. It lived between 92 million to 96 million years ago. The findings were published in the journal PeerJ. 
Mackenzie told ABC News that Australotitan was just “the tip of the iceberg” and that there are plenty of Australian sites brimming with potential for more fossil excavations. Australotitan was a plant eater, Hocknull noted, “so what was marauding around trying to eat these guys? We don’t have any evidence of that just yet.” Each discovery will help complete the story of Australia’s ancient past.

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In the age of dinosaurs, a succession of mega carnivores lorded over the landmass that is now North America. First came the 30-foot-long Allosaurus, 145 million years ago. Sixty million years later, the 40-foot-long T. rex reigned supreme. But scientists didn’t know what, or who, prevented T. rex from taking the throne during the intervening period. That is, until paleontologists from the Field Museum and North Carolina State University, on a dig in Utah, unearthed bones from the leg, tail, and spine of an all-new species. The researchers dubbed the dino Siats meekerorum after a man-eating monster in local Ute legend. The beast would have rivaled T. rex in size and power had the two coexisted. But only after Siats went extinct could tyrannosaurs, then the size of white-tailed deer, evolve into fearsome T. rex and assume the role of apex predator.

Other Nightmarish New Species

By Jessie Geoffray

The Chicken from Hell

Paleontologists from the University of Utah announced the discovery of this 11-foot-long dinosaur in March. The 500-pound raptor is the largest known oviraptorosaur—a group of dinos closely related to birds—found in North America. Anzu wyliei roamed the Dakotas with T. rex about 66 million years ago, just before dinosaur end-times.

Mouth Full of Switchblades

In Portugal, paleontologists uncovered what may be Europe’s largest known terrestrial predator. Torvosaurus gurneyi ruled the continent during the Jurassic Period 150 million years ago. It weighed in at 2,200 pounds, and stretched 33 feet from snout to tail. Some of its blade-shaped teeth measured nearly four inches long.

Polar Half-Pint

Nanuqsaurus hoglundi, a new tyrannosaur recently found by Texas paleontologists, is believed to have lived some 70 million years ago in the region that’s now Alaska. The pygmy dinosaur, whose name translates to “polar bear lizard,” was only half the length of its domineering cousin, T. rex, and 1/15 its weight.

An artist’s rendition of the 500-pound “Chicken From Hell”

This article originally appeared in the September 2014 issue of Popular Science.

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Lars Schmitz is an associate professor of biology at Scripps College; Jonah Choiniere is a professor of dinosaur paleontology at the University of the Witwatersrand; and Roger Benson is a professor of Palaeobiology at the University of Oxford. This story originally featured on the The Conversation.

Today, barn owls, bats, leopards and many other animals rely on their keen senses to live and hunt under the dim light of stars. These nighttime specialists avoid the competition of daylight hours, hunting their prey under the cloak of darkness, often using a combination of night vision and acute hearing.

But was there nightlife 100 million years ago? In a world without owls or leopards, were dinosaurs working the night shift? If so, what senses did they use to find food and avoid predators in the darkness? To better understand the senses of the dinosaur ancestors of birds, our team of paleontologists and paleobiologists scoured research papers and museum collections looking for fossils that preserved delicate eye and ear structures. And we found some.

Using scans of fossilized dinosaur skulls, in a paper published in the journal Science on May 6, 2021, we describe the most convincing evidence to date for nocturnal dinosaurs. Two fossil species—Haplocheirus sollers and Shuvuuia deserti—likely had extremely good night vision. But our work also shows that S. deserti also had incredibly sensitive hearing similar to modern-day owls. This is the first time these two traits have been found in the same fossil, suggesting that this small, desert-dwelling dinosaur that lived in ancient Mongolia was probably a specialized night-hunter of insects and small mammals.

Looking to theropods

By studying fossilized eye bones, one of us, Lars Schmitz, had previously found that some small predatory dinosaurs may have hunted at night. Most of these potentially nocturnal hunters were theropods, the group of three-toed dinosaurs that includes Tyrannosaurus rex and modern birds. But to date, fossils for only 12 theropod species included the eye structures that can tell paleontologists about night vision.

Our team identified four more species of theropods with clues for their sense of vision—for a total of 16. We then looked for fossils that preserve the structures of the inner ear and found 17 species. Excitingly, for four species, we were able to get measurements for both eyes and ears.

Eye bones built for night vision

Scleral ossicles are thin, rectangular bone plates that form a ring-like structure surrounding the pupils of lizards as well as birds and their ancestors—dinosaurs. Scleral rings define the largest possible size of an animal’s pupil and can tell you how well that animal can see at night. The larger the pupil compared to the size of the eye, the better a dinosaur could see in the dark.

Since the individual bony ossicles of these rings fell apart after these animals died more than 60 million years ago, our team made scans of the fossils and then digitally reconstructed the eyes. Of all the theropods we examined, H. sollers and S. deserti had some of the proportionally largest pupils.

S. deserti‘s pupil made up more than half of its eye, very similar to night-vision specialists that live today like geckos and nightjars. Our team then compared the fossils to 55 living species of lizards and 367 species of birds with known day or night activity patterns. According to the statistical analyses our team performed, there is a very high chance—higher than 90 percent—that H. sollers and S. deserti were nocturnal.

But those were not the only two theropods our team looked at. Our analysis also found a few other likely nighttime specialists—such as Megapnosaurus kayentakatae—as well as daylight specialists like Almas ukhaa. But we also found some species—like Velociraptor mongoliensis—with eyesight seemingly adapted for medium light levels. This might suggest that they hunted around dawn or dusk.

Incredible ears of a dinosaur

In today’s nocturnal animals, hearing can be as important as keen eyesight. To figure out how well these extinct dinosaurs could hear, we scanned the skulls of 17 fossil theropods to decipher the structure of their inner ears and then compared our scans to the ears of modern animals.

All vertebrates have a tube-like canal called the cochlea deep in their inner ear. Studies of living mammals and birds show that the longer this canal, the wider the range of frequencies an animal can hear and the better they can hear very faint sounds.

Our scans showed that S. deserti had an extremely elongated inner ear canal for its size—also similar to that of the living barn owl and proportionally much longer than all of the other 88 living bird species we analyzed for comparison. Based on our measurements, among dinosaurs, we found that predators had generally better hearing than herbivores. Several predators—including V. mongoliensis—also had moderately elongated inner ears, but none rivaled S. deserti’s.

The life of a nocturnal dinosaur

By studying the sensory abilities of dinosaurs, paleontologists like us not only are learning what species roamed the night, but can also begin to infer how these dinosaurs lived and shared resources.

S. deserti had extreme night vision and sensitive hearing, and this little dinosaur probably used its incredible senses to hunt prey at night. It could likely hear and follow rustling from a distance before visually detecting its prey and digging it up from the ground with its short single-clawed arms. In the dry, desert-like habitats of millions of years ago, it might have been an evolutionary advantage to be active in the cooler temperatures of the night.

But according to our analysis, S. deserti wasn’t the only dinosaur active at night. Other dinosaurs like V. mongoliensis and the plant-eating Protoceratops mongoliensis both lived in the same habitat and had some level of night vision.

Paleontologists currently do not know the full suite of animals that shared S. deserti’s extreme nocturnal lifestyle in the ancient deserts of Mongolia—it is rare to find fossils with the right bones intact that allow paleontologists to investigate their senses. However, the presence of a specialized night forager highlights that much like today, some dinosaurs avoided the dangers and competition of daylight hours and roamed under the stars.

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There’s a reason that Tyrannosaurus rex has earned its reputation as the king of dinosaurs. Its massive size and powerful, bone-crunching jaws made T-rex a force to reckon with (or, more likely, flee from). But the species wasn’t born that way. Like humans, T-rexes have a period of teenage growth years. Adolescent T-rexes were built and hunted markedly differently from adults, indicates a study published January 1 in the journal Science Advances.

By analyzing leg bones from two skeletons, paleontologists found evidence that they belonged to half-grown T-rex and not, as some researchers have proposed, a smaller species of tyrannosaurid. The team concluded that T-rex didn’t come into its full strength and bulk until late in adolescence. The two youngsters provide a rare window into this early—but no less ferocious—period in T-rex’s life.

“These specimens were clearly very young, fast-growing animals,” says Lawrence Witmer, a paleontologist at Ohio University in Athens who was not involved in the research. “So the question becomes, are these young Tyrannosaurus rex? I think that the chances of that are really quite high.”

What T-rex looked like during its teen years—whether it was a mini version of its adult self or distinctively shaped—has been an ongoing controversy in the paleontology world. The debate started with a skull discovered in the 1940s and which now resides in the Cleveland Museum of Natural History, according to Holly Woodward, a paleontologist at the Oklahoma State University Center for Health Sciences in Tulsa and lead author of the new study. Its shape was odd enough that in the 1980s a group of researchers pegged it as belonging to a separate genus they called Nanotyrannus.

Then in the early 2000s, the two skeletons that Woodward investigated—which go by the nicknames of “Jane” and “Petey”—were discovered in Montana’s Hell Creek Formation and the debate continued. Paleontologists had noticed that the Cleveland fossil and Jane (whose bones include a nearly complete skull) had more teeth in their jaws than an adult T-rex would, Witmer says. He and his colleagues have reported that young members of a close relative called Tarbosaurus bataar have the same number of teeth as adults.

However, Witmer says, it’s very possible that T-rex lost teeth as it matured. He and most other paleontologists now believe that the mysterious skeletons are probably all adolescent Tyrannosaurus rex.

“Not all pieces of evidence necessarily point in the same direction…but to me the really exciting part of this [new research] is what it tells us about T-rex itself, how it grew and how it lived its life,” he says.

Rather than examining the shape of the bones, Woodward and her team peeked inside them, zooming in on slivers of femur and tibia bone less than a millimeter thick. “Bone fossilizes even on the microscopic scale, so you can see those microstructures and it looks just like modern bone does,” Woodward says.

To preserve as much information from the skeletons as possible, the researchers created 3D laser scans of the bones before cutting into them as well as replicas of the bone slivers they removed.

She and her team saw a number of features that suggested the dinosaurs had been teenagers when they died. The fine fibers within the bone tissue were arranged in all different directions, rather than neatly layered, similar to the fast-growing bones found in present-day juvenile animals. The bone was also full of marks where blood vessels once grew.

“If bone is growing very quickly it needs more nutrients to help the bone cells that are producing the bone live and do their job,” Woodward says. “The rich vascular networks [together] with the presence of disorganized bone tissue suggests that they were juveniles and they were growing quickly, rather than the slow growth that you see when something is getting to be its final size.”

She and her colleagues also examined growth rings, which resemble tree rings and form each year when bone growth briefly pauses for a couple months before firing up again. By counting the rings in Jane and Petey’s bones, Woodward concluded that the dinosaurs were, respectively, 13 and 15 years old when they died. Intriguingly, the amount of space between each ring varied from year to year—meaning the dinosaurs could grow more slowly in lean years and rapidly during times of plenty.

An adult Tyrannosaurus rex like “Sue,” a skeleton at the Field Museum of Natural History in Chicago, would take 20 years to reach its full length of around 40 feet and weigh in at about 21,000 pounds. Jane and Petey, which are housed at the Burpee Museum of Natural History in Rockford, Illinois, were only half that size and probably weighed a mere 2,100 pounds.

Not large, but still in charge

The analysis of Jane and Petey’s bones suggest that T-rex took a long time to approach its adult size. This means that during their lengthy adolescence, Jane and Petey were more svelte and would have followed a very different lifestyle than their mature counterparts.

T-rex was probably similar in many ways to modern alligators, which prey on different animals at different stages of their lives. Young alligators dine on insects and small fish, while adults can eat pretty much whatever they want, Woodward says.

Both teen and adult T-rexes would have scavenged when possible. However, when a free meal wasn’t available, a teenaged T-rex could have chased after small herbivores and other young dinosaurs that hadn’t reached their full size, such as the duck-billed Edmontosaurus. A young T-rex like Jane was more delicate than an adult and had teeth resembling steak knives that were built for tearing through flesh.

“Their hunting style was probably more of an attack and retreat, attack and retreat, whereas the adults would just basically wade right into battle and chomp down on their prey,” Witmer says. “These young T-rexes in some respects are even more terrifying than the adults, because the adults were relatively slow-moving and slower to turn, but these young T-rexes were very quick.”

A bulky adult T-rex wouldn’t have been fast enough to pursue small prey. But then, it wouldn’t need to. “The adults we know became incredibly powerful animals,” Witmer says. “Their jaw muscle chamber just exploded in size.” As T-rex’s teeth thickened and became more banana-shaped, it gained the ability to bite down with enough force to crush bone (it could even have easily ripped through a car roof, were one available). This transformation matches what Witmer has observed in juvenile Tarbosaurus specimens excavated in Mongolia, which also appear more delicate than their adult form.

T-rex’s ability to pause or speed up growth may explain how it thrived at all sizes during its heyday in the late Cretaceous period. “It also maybe shows the reason why we don’t find any other medium to large carnivores in the Hell Creek ecosystem,” Woodward says. “T-rex only had to compete with other T-rexes of similar size; it didn’t have to compete with other species because it was dominating each niche as it was getting bigger.”

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Majungasaurus never needed dental work. If it had tooth problems, it just had to wait a couple of months. A new study of the carnivorous dinosaur who lived during the Late Cretaceous period, about 70 million years ago, demonstrates that it grew a whole new set of teeth about every two months. That’s the fastest replacement rate of any carnivorous dino identified to date.

Majungasaurus lived in what is now Madagascar, in a world populated by giant crocodilians with heads shaped like toilet bowls, long-necked herbivorous sauropods, and hundreds of birds. “It was a fairly harsh environment at times,” says paleontologist Andrew Farke of the Alf Museum of Paleontology, who was not involved in the study. Late Cretaceous Madagascar had pronounced wet and dry seasons, leading to periods of feast or famine. Somehow, in this world, it made sense to lose your teeth every two months—at least for Majungasaurus.

Stony Brook University, where the paleontologists who discovered Majungasaurus worked in the 1990s, boasts a huge collection of the dinosaur’s teeth (and a 21-foot-long replica skeleton in the lobby of its administration building). That plentiful array allowed researchers to get CT scans of 52 individual teeth and 15 Majungasaurus jaw pieces containing chompers, which showed them how the teeth formed and how they fit into the mouth. But it didn’t show them how long they took to grow—for that, they had to physically take apart 19 of the teeth they’d scanned. “You cut it the same way a jeweler would cut a gem,” says study author Michael D’Emic, an Adelphi University biologist.

After sectioning the teeth very thinly and mounting each section on a slide, he says, it’s possible to look under a microscope and see the tooth rings, which represent a specific rate of growth—just like the rings of a tree. Previous research has demonstrated that one line represents one day of growth in most dinosaurs. “We basically used our many cut-up teeth as stand-ins for the ones we saw in the jaws,” says D’Emric. By doing some math, they could estimate how long it would take the teeth in the jaws they scanned to form.

The results suggest that Majungasaurus cycled through chompers every two months, which is double the next-closest rate previously seen in carnivorous dinosaurs. This speed parallels what we’ve seen in herbivorous dinosaurs, says D’Emric. Scientists think those creatures went through teeth fast, at least in part, because they were grinding up lots of fibrous plants. Carnivorous dinosaurs, on the other hand, tore into the relatively soft meat of other animals. He and his colleagues think that Majungasaurus must have eaten bones, which would have created a similar level of wear-and-tear.

If the thought of losing your teeth every two months is giving you the creeps, don’t panic: Majungasaurus wasn’t shedding the kind of built-to-last hunks of bone found in human adults. “[The dinosaur’s] teeth individually are not very durable and are low quality,” says D’Emric. They don’t have much enamel, for instance, which is the hardest (and hardest-to-grow) part of modern mammalian teeth. Dinosaurs took a use ‘em and lose ‘em approach, just like crocodiles and alligators still do today. That’s why Stony Brook was able to amass such a huge collection of Majungasaurus teeth in the first place, says D’Emric: They left a lot of them lying around.

Those scattered dino teeth still have plenty left to teach us, says Farke, and studying them could tell scientists a lot about how the creatures lived. “Teeth are one of the most fundamental ways by which an animal interacts with its environment,” he says. “If you want to live, you’ve got to eat.”

Farke says the Majungasaurus study, which also looked at smaller samples of teeth from two other carnivorous dinosaurs, is a good start. But to truly understand what was going on in the mouth of this animal millions of years ago, and how it lived, he says more research, as always, is needed.

“I think the authors did a good job of collecting as big a sample as they could,” he says. “But the picture always gets more complex when you get more things added in.”

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Thorsten Lumbsch, curator of lichenized fungi at the Field Museum, uses his subway commute to read scientific papers.

“I like to read the stuff that has nothing to do with my research,” he says—which is how he found himself totally absorbed in a paper about the asteroid that collided with Earth 66 million years ago, decimating dinosaurs, birds, insects, and all manner of other life.

To understand how that cataclysmic collision impacted lichens—co-dependent organisms made of fungi and algae or cyanobacteria—Lumbsch and some colleagues studied the DNA of modern lichen to trace their evolution. Their findings, published Friday in Scientific Reports, shows that three families of lichens rapidly took hold and diversified after the asteroid event—contrary to what the scientists expected at the outset of their research.

Fungi—a kingdom of life separate from plants and animals that includes mushrooms, yeasts, and molds—are the natural world’s decomposers. Some are parasitic, like the white nose syndrome plaguing North America’s bats or the chytrid fungus that has infected some 500 amphibian species. Others are symbiotic, like the fungus that live alongside trees, or the lichens all around us.

“You’ve seen lichens a million times, even if you didn’t realize it,” says Jen-Pan Huang, a co-author of Friday’s paper, in a press release about the study. “If you go on a walk in the city, the rough spots or gray spots you see on rocks or walls or trees, those are common crust lichens. On the ground, they sometimes look like chewing gum. And if you go into a more pristine forest, you can find orange, yellow, and vivid violet colors.”

Before they set out to find the answer, Lumbsch and Huang doubted lichens would have fared well after the asteroid-caused mass extinction. Clouds of ash from the crash coated the skies, blocking sunlight and cooling the planet—which made it hard for photosynthesizing plants to survive. Since lichens contain a plant and a fungus, it seemed those conditions would impede their survival.

“I thought, the fungi, they must have had a great time—there was so much death,” Lumbsch says. “But the lichens, they must have really suffered. The problem with lichen is there’s very few fossils, so we don’t know what became extinct through these events.”

By comparing the DNA sequences of different modern species of lichen, Lumbsch’s team were able to extrapolate how long ago they had a common ancestor, and map their family tree and when each of its branches formed to become the groups of lichen we see today. For the study, they also examined the rare lichen fossils available to them from hundreds of millions years ago.

Altogether, their findings suggest a boom in some types of leafy lichen diversity after the asteroid collision. Which kind of makes sense, Lumbsch says, if you think of the collision as wiping a blank slate for fresh forms of life to emerge from.

“Ecological niches were free and could be filled by new species,” Lumbsch explains. “It fits into this emerging picture that tells us there was really a turnover of the whole fauna and flora through this event 66 million years ago… What we see now in the vegetation around us is the product of an evolution that began after this event.”

Zooming out, Lumbsch thinks this study highlights how a dramatic event can reshape the environment for millions of years afterward—which suggest the ecological impact of the human-caused mass extinction we face today will ripple out for an untold period of time.

“Some groups suffer, some groups are favored,” Lumbsch says. “This tells us we can expect a change of climate will definitely impact the evolution of species.”

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For February, we’re focusing on the body parts that shape us, oxygenate us, and power us as we take long walks on the beach. Bony bonafide bones. These skeletal building blocks inspire curiosity and spark fear in different folks—we hope our stories, covering everything from surgeries and supplements to good old-fashioned boning, will only do the first. Once you’ve thoroughly blasted your mind with bone facts, check out our previous themed months: muscle and fat.

Scientists have identified the oldest-known case of a unique kind of cancer in the tailbones of a duck-billed dinosaur. The abnormalities preserved in the ancient reptile’s bones match those seen in people today who are afflicted with this rare disease, the researchers announced February 10 in Scientific Reports.

Studying the fossilized traces of diseases in dinosaurs can shed light on how long certain maladies have existed and how they have changed over time, says Bruce Rothschild, a vertebrate paleontologist at the Carnegie Museum of Natural History in Pittsburgh and coauthor of the new study.

“This is not the first tumor that has been discovered in dinosaurs, but it’s the first of this particular variety,” he says. “When they occur in the dinosaurs, they don’t look any different than they do in us.”

Diagnosing illness in dinosaurs isn’t easy. Most of their soft tissue rotted away millions of years ago and the skeletons that remain are often incomplete. Still, paleontologists have been able to identify an impressive array of ailments, from gout to arthritis and cancer. The duck-billed dinosaurs, or hadrosaurs, seemed to be particularly prone to tumors for reasons that remain a mystery, Rothschild says. These herbivorous dinosaurs lived in large herds during the late Cretaceous and could grow to more than 30 feet long and weigh several tons.

Hadrosaur fossils have been found around the world but are particularly common in Alberta, Canada. When Rothschild examined fossils his colleague Darren Tanke, of the Royal Tyrrell Museum of Palaeontology in Alberta, had collected from this region, he noticed two vertebrae from a juvenile hadrosaur that bore distinctive signs of disease.

“This particular specimen had some features very different from what we had previously seen in dinosaurs,” Rothschild says. Within the hadrosaur bones were cavities that had an odd, meandering border reminiscent of those seen in people with a disease called Langerhans Cell Histiocytosis (LCH). “There’s very little else that does that, so it’s pretty characteristic.”

LCH is most commonly seen in children and causes immune cells to build up and form benign—but often painful—tumors in the skull, spine, other bones, or occasionally other parts of the body. When Rothschild and his colleagues examined the dinosaur bones under the microscope, they observed that the cavities had wrinkled bases that are unique to this rare disease.

The researchers then used a technique called micro-CT scanning to create virtual 3D reconstructions of the tumors. The team compared the dinosaur bones with vertebrae from people who had been diagnosed with LCH while alive, and found that the ancient reptilian tumors were “indistinguishable” from human ones. This means LHC has been afflicting the animal kingdom for more than 60 million years.

Investigating how dinosaur’s bodies were altered by disease can also give paleontologists a window into how they coped with adversity and how they survived despite challenges. Fossils might provide evidence about how often a dinosaur needed to eat and if it could wait to recover from an injury before hunting, Rothschild says, or whether a sick dinosaur could have survived with help from its pack-mates.

“When you look at dinosaurs, you recognize that they suffered the same types of problems [as humans].” Their resilience, he says, is quite impressive.

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When you think about Scotland, the first images that pop into your mind are probably of gorgeous cliffs and men in kilts. But rewind a few million years, and Scotland was hardly the place we know it as today. Its inhabitants were wildly different as well.

The Isle of Skye, for example, is one of the most picturesque spots in the modern Scottish Highlands, but it’s also home to a diverse array of tracks and fossils from middle-Jurassic creatures. A new paper published in PLOS One this week shows that among these ancient Scottish inhabitants is possibly an early cousin of a dinosaur fan favorite.

A team led by paleontologists Paige DePolo and Stephen Brusatte of the University of Edinburgh, Scotland, discovered new tracks back in 2017. One revealed an entirely new type of Scottish dinosaur: a plate-backed stegosaur.

“Stegosaurs are some of the most iconic dinosaurs of all,” says Brusatte, “and these handprints and footprints are the first evidence that they once inhabited Scotland.”

Stegosaurs are large, plant-eating creatures with rows of armored plates lining their spine, and are mostly known to be seen in the late Jurassic period (or in the Jurassic Park films). But the noteworthy thing about these footprints is that they were dated back millions of years before the existence of the most famous stegosaur of all — the Stegosaurus.

“These are also some of the oldest stegosaur fossils from anywhere in the world,” Brusatte adds, “so they tell us stegosaurs were evolving and diversifying at least by 170 million years ago, a good 20 million years before the famous Stegosaurus itself lived.”

The middle Jurassic is a bit of a mystery. Finding dinosaur fossils and tracks in terrestrial sediment from that time is “so doggone rare,” says Brooks Britt, a paleontologist at Brigham Young University who was not involved in the study. Finding anything, especially tracks of a creature we mostly associate with the late Jurassic, is a huge deal.

Tracks, Britt says, show where the dinosaur actually was walking around. In contrast, fossils can be transported miles away from their original location by rivers and other waterways.

“With tracks, you know they were walking along that beach,” he says.

But of course, the dinosaurs were tracking around a wildly different world than the one we see today in Scotland. Back 170 million years ago during the middle Jurassic, all modern continents were stuck together in a singular mass called Pangea, and the chunk we know as Scotland today had a warm, humid climate—kind of like Florida, Brussatte says. This Jurassic Scotland, with rivers, mountains, and lagoons, created homes for all sorts of dinos, including previously discovered massive long-necked sauropods and carnivorous dinosaurs as big as jeeps.

With this new discovery, ancient stegosaurs can be added to the mix, and even possibly another type of dinosaur which left large, three-toed tracks that resemble those of duck-billed dinosaurs dated back to the upper Jurassic.

Whether or not these guys were decked out in iconic Scottish tartan is up to your imagination.

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Perhaps the most amazing thing about fossils is that they don’t just show us what extinct animals looked like, they can also reveal how those animals lived. Even a fossilised dinosaur egg can provide a wealth of clues about its parents’ behaviour.

Dinosaur hunters in the Javkhlant region of the Gobi Desert in Mongolia recently discovered 15 exceptionally well preserved clutches of eggs that came from a species of theropod dinosaur. Through some fantastic detective work, the researchers argue that this fossil site provides the strongest evidence yet that such dinosaurs nested in colonies and protected their eggs.

I’m a behavioural ecologist. I study how animals live their lives and how species fit together in ecosystems. We can uncover the behavioural ecology of past species and ecosystems by using fossils and our knowledge of animals and habitats today. In this case, I suggest that these dinosaurs may have protected their eggs as a community rather than caring solely for their own nests. It is also possible that these dinosaurs didn’t need to care for their young once they had hatched.

The spherically-shaped eggs were found in clutches of between three and 30 eggs in what was a seasonally arid flood plain. They were laid towards the end of the Cretaceous period around 66m years ago, not long before the dinosaurs disappeared.

The eggs are between 10cm and 15cm in diameter, similar in size to those of the largest living bird species, the ostrich. By comparing the eggs with fossilised embryonic remains in other eggs, the scientists identify that these specimens likely came from the Therizinosauroidea family.

The shells of the eggs have a high porosity, meaning they contain lots of tiny holes. The researchers looked at how this compares to the eggs of living species. We know these dinosaurs lived in a dry, arid environment, and animals in these habitats (such as ostriches) typically lay eggs with few pores in order to minimise water loss.

Instead, the high porosity of the Javkhlant eggshells is similar to those of Australasian megapode birds such as the mallee fowl, and crocodilians. These species cover or bury their eggs in organic-rich material, which generates heat as it rots, in order to incubate the eggs. The high porosity of the Javkhlant eggs suggests these dinosaurs did the same because the pores would have made it easier for the developing embryo to breathe in the damp, oxygen-poor environment of rotting vegetation.

The fossils also indicated that all the eggs were laid and hatched in the same nesting season, providing evidence that the dinosaurs nested in colonies. About 60% of them hatched successfully, a relatively high hatching rate similar to that of modern birds and crocodilians that protect their eggs. This supports the argument that these dinosaurs also looked after their nests.

Evidence for dinosaur parental care most famously comes from a fossil of what was thought to be a mother Oviraptor found sitting on a nest of eggs. New understanding of dinosaur skeletons suggests this “Big Mama” should actually be renamed “Big Papa”. Male (paternal) care may have been the ancestral form of parental care, with birds evolving from theropod dinosaurs (birds are avian dinosaurs). In the most primitive group of living birds (including the ostrich) it is usually the male birds that sit on eggs.

However, in the case of our Therizinoid dinosaurs, we think the eggs were buried, which would mean the parents wouldn’t need to sit on them for incubation. But that doesn’t mean they abandoned the eggs completely.

Modern megapode bird and crocodilian species that abandon or rarely attend their eggs after laying and burying them have relatively low hatching success rates (under 50%) because of predators attacking the nests. But, as we’ve seen, the Javkhlant eggs had a higher hatching rate of 60%.

Communal breeding

If the adult dinosaurs didn’t physically incubate their eggs but did protect the nests at a communal site, this could indicate communal defence of the eggs or communal breeding, whereby individuals provide “alloparental” care for the offspring of others.

However, megapode chicks are superprecocial. This means when they hatch they can survive completely independently and so don’t receive any (post-hatching) parental care. So, while the high hatching success indicates these dinosaurs looked after their eggs, it may be that they didn’t need to protect their young once they did hatch.

Unfortunately, the constraints of the fossil record mean it would be very difficult to find direct evidence of communal breeding and cooperative care in dinosaurs. We would need evidence of more than two adults caring for a single brood, or of one adult caring for more eggs than could be laid in a single clutch.

Whatever future fossil finds serve up, there is no question that they will open more windows of understanding into the behavioural ecology of long-extinct dinosaurs. Our understanding will also be informed, not only by the fossils themselves, but by interpretation of the behaviour of modern species. The behavioural dynamics of dinosaur ecosystems were not so different from those of today.

Jason Gilchrist is an Ecologist, Edinburgh Napier University. This article was originally featured on The Conversation.

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In the past half-billion years, Earth has been hit again and again by mass extinctions, wiping out most species on the planet. And every time, life recovered and ultimately went on to increase in diversity.

Is life just incredibly resilient, or is something else going on? Could mass extinctions actually help life diversify and succeed—and if so, how? Given that we’re currently facing another extinction event, there’s extra urgency in trying to work out how mass extinctions affect diversity.

Mass extinction is probably the most striking pattern in the fossil record. Vast numbers of species—even entire families—disappear rapidly, simultaneously, around the world. Extinction on this scale usually requires some kind of global environmental catastrophe, so severe and so rapid that species can’t evolve, and instead disappear.

Massive volcanic eruptions drove the extinctions at the end of the Devonian, Permian and Triassic periods. Global cooling and intense glaciation drove the Ordivician-Silurian extinctions. An asteroid caused the end-Cretaceous extinction of the dinosaurs. These “Big Five” extinctions get the most attention because, well, they’re the biggest. But lots of lesser yet still civilisation-threatening events occurred as well, like the pulse of extinction before the end-Permian event.

These events were indescribably destructive. The Chicxulub asteroid impact that ended the Cretaceous period shut down photosynthesis for years and caused decades of global cooling. Anything that couldn’t shelter from the cold, or find food in the darkness—which was most species—perished. Perhaps 90% of all species disappeared in just a few years.

But life bounced back and the recovery was rapid. 90% of mammal species were eliminated by the asteroid, but they recovered and then some within 300,000 years, going on to evolve into horses, whales, bats and our primate ancestors. Birds and fish experienced similarly rapid recovery and radiation. And many other organisms—snakes, tuna and swordfish, butterflies and ants, grasses, orchids and asters—evolved or diversified at the same time.

This pattern of recovery and diversification happened after every mass extinction. The end-Permian extinction saw mammal-like species take a hit, but reptiles flourished afterward. After the reptiles suffered during the end-Triassic event, the surviving dinosaurs took over the planet and diversified. Although a mass extinction ended the dinosaurs, they only evolved in the first place because of mass extinction.

Despite this chaos, life slowly diversified over the past 500m years. In fact, several things hint that extinction drives this increased diversity. For one, the most rapid periods of diversity increase occur immediately after mass extinctions. But perhaps more striking, recovery isn’t only driven by an increase in species numbers.

In a recovery, animals innovate – finding new ways of making a living. They exploit new habitats, new foods, new means of locomotion. For example, our fish-like forebears first crawled onto land after the end-Devonian extinction.

Evolutionary innovation

Extinction doesn’t only drive this process of speciation. It also drives evolutionary innovation. It’s not a coincidence that the biggest pulse of innovation in life’s history – the evolution of complex animals in the Cambrian Explosion – happened in the wake of the extinction of the Ediacaran animals that went before them.

Innovation may increase the number of species that can coexist because it allows species to move into new niches, instead of fighting over the old ones. Fish crawling onto land didn’t compete with fish in the seas. Bats hunting at night with sonar didn’t compete with birds that were active during the day. Innovation means evolution isn’t a zero-sum game. Species can diversify without driving others extinct. But why does extinction drive innovation?

Stable ecosystems may prevent innovation. A modern wolf is probably a far more dangerous predator than a velociraptor, but a tiny mammal couldn’t evolve into a wolf in the Cretaceous because there were velociraptors. Any experiments in carnivory would have ended badly, with the poorly adapted mammal competing with—or just eaten by—the already well-adapted Velociraptor.

But, in the lulls after an extinction, evolution may be able to experiment with designs that are initially poorly adapted, but with long-term potential. With the show’s stars gone, the evolutionary understudies get their chance to prove themselves.

The extinction of Velociraptor gave mammals the freedom to experiment with new niches. Initially, they were poorly equipped for a predatory lifestyle, but without dinosaurs competing with or eating them, they didn’t need to be terribly good to survive. They only needed to be as good as the other things around at the time. So they flourished in an ecological vacuum, ultimately evolving into big, fast, intelligent pack hunters.

Creative destruction

Life isn’t just resilient, it thrives on adversity. Life will even recover from the current wave of human-induced extinctions. If we disappeared tomorrow, then species would evolve to replace woolly mammoths, dodo birds and the passenger pigeon, and life would likely become even more diverse than before. That’s not to justify complacency. It won’t happen in our lifetime, or even the lifetime of our species, but millions of years from now.

This idea that extinction drives innovation may even apply to human history. The extinction of ice-age megafauna must have decimated hunter-gatherer bands, but it also may have given farming a chance to develop. The Black Death produced untold human suffering, but the shakeup of political and economic systems may have led to the Renaissance.

Economists talk about creative destruction, the idea that creating a new order means destroying the old one. But evolution suggests there’s another kind of creative destruction, where the destruction of the old system creates a vacuum and actually drives the creation of something new and often better. When things are at their worst is precisely when the opportunity is the greatest.

Nick Longrich is a Senior lecturer of Palaeontology, at Milner Centre for Evolution, University of Bath.

This article was originally featured on The Conversation.

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Scientists claim to have finally found a “plausible theory” for sightings of the Loch Ness Monster. She’s not an aquatic reptile left over from the Jurassic era or a circus elephant that got in the water to bathe with her trunk aloft. If Nessie ever existed at all, she was most likely a giant eel, according to a new scientific survey of the loch.

Starting with an Irish missionary’s report of a monster in the River Ness in 565AD, repeated sightings in the modern era have kept Scotland’s greatest myth alive. The most famous of which is a grainy photo from 1934 which appears to show the shadowy outline of a long-necked creature, bobbing on the water’s surface.

The hoaxed photo of the Loch Ness monster taken in 1934 by Colonel Robert Wilson. Until now, such glimpses were all people had to go on. But a new technique allows scientists to sample all the life contained within Loch Ness by gathering environmental DNA, or e-DNA as it’s known. This is genetic material that’s present in the cells of organisms and shed into their surrounding environment. Finding and identifying e-DNA can tell scientists what organisms are living in a habitat without them having to observe or capture them.

Speaking from Drumnadrochit, a village on the western shore of Loch Ness, scientists announced the results of their e-DNA survey of Loch Ness. The team took well over 200 one-liter samples of water from throughout the loch—including the surface and deep water—and compared them with 36 samples from five “monster-free” lochs nearby. Their census provides a list of all the species that call Loch Ness home—from bacteria to plants and animals.

What did they find?

The study detected over 500 million DNA sequences and 3,000 species. According to Neil Gemmill of University of Otago in New Zealand, who led the study, there are no DNA sequence matches for shark, catfish, or sturgeon. That rules out a large exotic fish in the loch.

There are DNA matches for various land-living species that you would expect to see around Loch Ness, including badgers, deer, rabbits, voles, and different birds. Sheep, cattle, and dogs appear on the record alongside humans too. This suggests that the sampling is pretty good at picking up species that would only rarely visit the water—so it should be able to detect a monster living permanently in the loch.

The most popular representation of Nessie is as a plesiosaur—an ancient long-necked marine reptile that died out alongside the dinosaurs in the last great mass extinction 65 million years ago.

Scottish geologist Hugh Miller discovered the first British plesiosaur bones on the Scottish Isle of Eigg in 1844. But according to Gemmill, there’s “not a single reptile in our vertebrate data, and nothing that sat in the expected place that a plesiosaur [DNA] sequence might be predicted to lie—somewhere between birds and crocodilians”.

The most likely candidate for Nessie that has surfaced in media reporting of the research is a giant eel. This appears to be based simply on the fact that eel DNA was detected at “pretty much every location sampled” in Loch Ness.

Plenty of eel DNA doesn’t confirm that Nessie is a giant eel—only that there are lots of eels. Scientists don’t have monster DNA to compare with anything they found in the loch and so no one can say for sure if there is or isn’t a monster there. But the absence of anything unusual in the DNA record of Loch Ness suggests there’s nothing to get excited about—and that includes a giant eel.

What next for Nessie?

If Nessie doesn’t exist, why do eyewitness accounts of the Loch Ness Monster persist? The answer is likely to be a psychological phenomenon called “expectant attention”. This happens when people who expect or want to see something are more likely to misinterpret visual cues as the thing that they expect or want to see.

This likely also happens with recently extinct animals. The last known Tasmanian tiger died in 1936 and exhaustive scientific surveys have failed to turn up any evidence that they’re still out there. Even so, people often still report seeing them.

Still, Gemmell acknowledges that there is uncertainty. Seals and otter—two species known to appear in the loch at least occasionally—weren’t detected, while 20% of the DNA collected was “unexplained.” That’s normal for an e-DNA study, but it does leaves room for a monster.

A YouGov poll in August 2018 found that 24 percent of Scots believe that Nessie exists. First Minister for Scotland Nicola Sturgeon is apparently among them.

Science being science, we can never say with total confidence that there is no Loch Ness Monster. The Loch’s thriving tourism industry can still count on a little mystery to attract true believers. Rest easy, monster hunters. Nessie lives on.

Jason Gilchrist is an ecologist at Edinburgh Napier University in Scotland. This article was originally featured on The Conversation.

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A newly discovered dinosaur was a cousin of Velociraptor but might have been an even more formidable hunter than its family member.

The raptor, which the researchers have named Dineobellator notohesperus, lived in northwestern New Mexico at the end of the Cretaceous Period. When paleontologists examined a partial skeleton of Dineobellator, they found features in its forelimbs, claws, and tail indicating that the dinosaur was both strong and nimble.

The fossils are among the youngest known for any member of the raptor, or dromaeosaurid, family, and indicate that this group was splitting into new species right up until the end of the dinosaurs’ reign, says Steven Jasinski, a paleontologist at the State Museum of Pennsylvania in Harrisburg. He and his colleagues described the new species March 26 in the journal Scientific Reports.

Dromaeosaurids are a family of swift, lightly built predators with an enlarged “killing claw” on each foot. They seem to have had relatively big brains for their size and hunted in packs. Fossils of this family are rare, particularly from the Late Cretaceous.

Jasinski and his colleagues stumbled across the first evidence of a previously unknown dromaeosaurid in 2008, when they found a distinctive claw in New Mexico’s San Juan Basin. On subsequent trips, they unearthed enough bone fragments and relatively complete bones to distinguish the new species from its relatives.

The team estimates that Dineobellator was a medium-sized dromaeosaurid about 6 to 7 feet long and 3 feet tall at the hip that weighed around 40 to 50 pounds. Little bumps known as quill knobs indicate that the animal had large forearm feathers as well as feathers throughout its body. The researchers also examined attachment sites for muscles in its upper arms, hands, and feet, and concluded that Dineobellator would have gained more strength from flexing its arms than the typical dromaeosaurid, as well as having a more powerful grip.

Dromaeosaurids generally had stiff, straight tails reinforced with rod-like bones and tendons that made the tale balance out the rest of the body while they chased down prey. “The difference with Dineobellator is the base of the tail close to the hips was highly mobile, which means it could move around very quickly,” Jasinski says.

In this way, Dineobellator might have resembled present-day cheetahs, which can change direction mid-dash by quickly flipping their tails around while keeping them stiff enough to counterbalance their movements. “It suggests that Dineobellator would have been not only very fast but also highly agile and a really good pursuit predator,” Jasinski says.

The Dineobellator specimen that Jasinski and his team inspected also had evidence of a healed rib injury and a gouge mark on one of its hand claws. Based on the size and shape of the puncture, the researchers suspect it was made by a fellow Dineobellator, perhaps during a squabble over food or mates.

Dineobellator’s unique combination of strength and agility could have given the animal an edge compared with other dromaeosaurids; its close relative the Velociraptor was a fast sprinter but probably couldn’t turn as easily. It’s likely that Dineobellator took down small, swift creatures and swarmed dinosaurs several times its size such as the hadrosaurids, or duck-billed dinosaurs. Tyrannosaurids like T-rex were probably too slow to catch Dineobellator, but might have routinely stolen their lunch “just due to being able to kind of bully them out of the way,” Jasinski says.

Not everyone, however, is convinced of the new species’ super-powered arms. Sara Burch, a paleontologist at SUNY Geneseo, says more evidence is still needed to show that Dineobellator did indeed have unusually strong limbs.

“I think we need to be careful trying to infer major functional characteristics of the forelimb based on one or two muscles,” she said in an email to Popular Science. “This paper points out some interesting characteristics of Dineobellator in comparison to other dromaeosaurids, but in order to really understand forelimb function in any extinct animal we need to look [at] all the muscles together.”

Still, Burch said, the discovery of this fearsome raptor provides valuable new information about the family’s evolutionary history.

“We have known for a long time that there were dromaeosaurids in the latest Cretaceous because of preserved teeth,” she said. “Now we are finally finding out what those dromaeosaurids might have looked like.”

The rock surrounding the fossils is 68 million years old, which means that Dineobellator roamed New Mexico not long before the asteroid strike that brought the Cretaceous Period to an abrupt end.

“Some scientists think that dinosaurs in general were declining at the very end of the Cretaceous right before the mass extinction,” Jasinski says. “But this suggests that [dromaeosaurids] were still diversifying and still doing well until the catastrophic event that ended all non-avian dinosaurs.”

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To some extent, fossils are like photographic images of the past. A still from millions or even billions of years ago becomes preserved within the bedrock of the Earth, underneath layers that have accumulated over time. If you’re lucky, you can use these specimens as a snapshot into the past. By that logic, a new set of fossils found in North Dakota could potentially give us our best pictures yet of the extinction event that wiped out the dinosaurs 66 million years ago—assuming the findings hold up to what’s already amounting to some serious scrutiny.

In a new study published in the Proceedings of the National Academy of Sciences on Monday and first announced in The New Yorker last week, a group of scientists analyze a huge cache of exquisitely preserved animal and fish fossils that lived and died in the moments surrounding the Chicxulub meteor impact. Scientists have long theorized that the rock that slammed into the Yucatan Peninsula in Mexico and created a 93-mile-long, 12-mile deep crater near the town of Chicxulub, led to the eradication of 75 percent of all plant and animal life on Earth. While Chicxulub was probably not solely responsible for the death of the dinosaurs (climate change and increased volcanic activity were also stressing the environment out at the time) it’s the moment that ended the Cretaceous period and heralded the rise of mammals.

“If dinosaurs were betting creatures, they’d probably be fairly upset with those odds,” says Phil Manning, a University of Manchester paleontologist and coauthor of the new study. “It was just bad timing for the dinosaurs, and great timing for the mammals.”

Nothing like this has ever been found before. The fossils “are the only concentrated assemblage of articulated [complete] carcasses at the K-T boundary known anywhere in the world,” says Robert DePalma, a doctoral student in geology at the University of Kansas and the lead author of the new study. “Elsewhere others have found isolated bones at the boundary, but never any articulated carcasses.” While the immediate effects of the Chicxulub impact vary from region to region, DePalma describes the site as illustrating the “first bloody nose” hit the meteor’s crash had on a region 2,000 miles away.

“As far as we know,” says Manning, “and I stand to be corrected if I’m wrong, this is the first time we have actual debris from the impact itself raining down onto an ecosystem, with organisms from that ecosystem found interacting with that debris.”

The K-T boundary (better known as the K-Pg boundary these days) is short for Cretaceous–Paleogene boundary, the geologic transition of the former period into the latter. There are sites all around the world that scientists have studied to better understand how this change occurred, but the Tanis site in North Dakota, located within the Hell Creek Formation, was not necessarily thought to be one of them. When DePalma and his colleagues first approached the Tanis site, there didn’t appear to be anything particularly special about it. “It was just another Hell Creek outcrop that we were visiting,” says Manning.

Eventually, however, the team was finding scores of fossilized paddlefish in the site—a rarity for Hell Creek. Other fossils included other marine creatures, terrestrial vertebrates, trees, branches, and plants. The 1.3-meter-thick sedimentology didn’t look like the Hell Creek or Fort Union formations; it was something that looked sandwiched in between, deposited very rapidly, like something you’d expect from a tsunami. The geochemistry of the area included pieces of ejected material associated with impact events, like shocked quartz and iridium-rich matter. Iridium is only found either deep in Earth’s core, or within meteorite materials. Subsequent dating techniques confirmed the ejecta matched well with the expected timing of a seismic shockwave to hit the region.

Here’s the picture the research team paints: 66 million years ago, marine bodies lived in some kind of water channel that existed within a deep valley. Suddenly, a six- to-seven-mile-long rock pummeled the planet at 40,000 miles per hour. Debris moving at ballistic speeds started to rain down onto the site. Seconds or minutes later, a massive shockwave thrust this water 10 meters high and dumped its contents (i.e. the marine organisms living in that channel) onto another bank, several times over in quick succession. “Literally throwing the baby out of the bathtub,” says Manning.

But the findings aren’t without dissenters. The New Yorker article that first broke the news quotes DePalma describing dinosaur specimens that are not at all discussed in the PNAS paper. In fact, only one dinosaur bone is mentioned by the researchers, in the supplement section. The connection of the Tanis findings to the death of the dinosaurs is not part of the published literature so far, making it difficult for paleontologists to really assess what the findings mean for the famous megafauna.

And DePalma is already a lightning-rod figure within the scientific community. He’s previously been criticized for misidentified a piece of a turtle shell as a wishbone of a newly discovered velociraptor genus (though it should be noted that misidentifications are not horribly uncommon, and don’t mean a scientist is acting in bad faith). He has an unusual reputation for retaining the rights over his specimens even after they’ve been made part of university and medium collections, which is controversial since scientists are supposed to study these objects objectively and dispassionately. He’s been called out for selling replicas of his findings, purportedly as a way to fund his research.

Manning pushes back on many of those criticisms—especially regarding past errors, which Manning calls “petty”—and is pretty enthusiastic about his work with DePalma. “I dock my hat to Robert,” says Manning. “He’s been a fine field geologist and paleontologist. Over the last seven years or so, he’s really gotten to know the site. Robert thankfully is inviting people very openly to work at the site, across multiple disciplines and from multiple countries.”

Manning also believes the team’s conclusions are supported by the data itself. “The absolutely most beautiful and elegant part of all of this is the geochemistry,” he says. Some of the tektites found at the site (glassy materials formed from molten crust, such as during impact events) had a “perfect chemical fingerprint” that Manning says matches them with other K-Pg boundary sites with material blasted out from the Chicxulub impact. “There is absolute evidence matching this site to the K-Pg impact” that created the Chicxulub meteor impact. The fossilized paddlefish (Acipenseriform) actually inhaled (and maybe choked on) tektite materials as debris rained down into the water. One of Manning’s favorite parts was finding fossilized amber that had managed to preserve some of the microtektite material almost perfectly, recording the chemistry from this event.

The findings also help us to understand how vast the Chicxulub impact really was, in ways we were just about clueless about before. “The deposit preserves the immediate aftermath of the impact in great detail, with minute-by-minute clarity, which is important for us to understand how exactly the impact affected Earth’s ecologies,” says DePalma. Bodies of water elsewhere in the world could have experienced similar surges after impact, giving scientists some clues about where else they may find sites similar to Tanis.

Mark Norell, the chair and Macaulay Curator at the American Museum of Natural History’s division of paleontology (who was not involved with the study) thinks the paper at least succeeds in demonstrating how vibrant and fascinating the Tanis site is from a paleontological and geological point of view. We’ve never before encountered a site with so much to unravel: preserved specimens of so many plants and animals, tektites, impact debris, and iridium concentrations of these levels. He thinks the findings are another step in helping to characterize what happened after impact, including the intense amount of heat generated, whether there was a tsunami or a swelling displacement of water created by shockwaves propagating through the ground, and more. The work being done at other K-Pg boundary sites ought to help confirm or dispute what’s been raised by the latest findings.

Norell does caution, of course, that the study is still quite preliminary. “Just like some of the other KT boundary stuff that exists, this is something that will need lots and lots of work—decades to really realize the full implications of it.” But based on the impressive list of authors attached to the new study, he’s confident the follow-up is going to be done at the highest levels of scientific scrutiny.

Still, it’s not really fair to ask the public to be cautious after researchers allowed the New Yorker to write 10,000 words on an unpublished study. Manning acknowledges there’s a significant margin for error in the findings. “I’ll be honest: if we’re wrong, I’d embrace it,” he says. “It’s part of the scientific method. My ears open to it. But we’re confident what we’ve put together is correct.” With only about 10 percent of the site’s fossils properly excavated and studied, and many other scientists expressing interest in visiting Tanis to do their own research, there’s plenty of heavy lifting left to do. Hopefully, it leads to some published insight into what Tanis might tell us about dinosaurs in particular. “We’re going to be working on it for a good many years,” Manning says.

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During these times of quarantine, last month feels like 100 million years ago. But if you were to actually go back to that period of time and make your way to the western Sahara, you’d likely run into a whole new set of problems in the form of hordes of enormous predators, according to a new study.

Instead of a desert, the region was covered by a vast river system that flowed up through present-day Morocco and Algeria. Strangely, paleontologists have found very few fossils of the plant-eating dinosaurs that roamed much of the world at the time. Rather, many of the fossils they have identified belonged to flesh-eating dinosaurs, flying reptiles called pterosaurs, and ancestors of modern crocodiles.

“It was arguably the most dangerous place in the history of planet Earth because it was home to so many different kinds of predators in all shapes and sizes,” says Nizar Ibrahim, a paleontologist at the University of Detroit Mercy. “This river of giants is unlike any ecosystem today, and in fact it’s also pretty unique compared to other dinosaur age ecosystems.”

Ibrahim and his colleagues have taken a sweeping look at the denizens and geology of this ecosystem, the remnants of which are preserved in the rock formations in eastern Morocco known as the Kem Kem Group or Kem Kem beds. Their report, published on April 21 in the journal ZooKeys, is based on the team’s findings from two decades of expeditions to the area and visits to fossil collections in museums around the world.

“This work represents the first detailed synthesis of all previous works on the geology and the paleontology of the Kem Kem Beds, and the first attempt to reconstruct the environmental conditions in this zone of North Africa between 100 and 95 million years ago,” Andrea Cau, an independent researcher who has collaborated with museums and universities in Italy, the United Kingdom, and elsewhere, told Popular Science in an email.

While some of the paleontological findings are still preliminary and will need to be confirmed with more detailed studies, the report could provide a valuable resource for paleontologists on future expeditions in the area, said Cau, who has studied the Kem Kem Group and other ancient ecosystems in northern Africa.

The area dubbed the Kem Kem Group consists of layers of sedimentary rock exposed on a long, winding escarpment near the border between Morocco and Algeria. The fossils found here are a motley bunch.

“You get very small things—tiny little amphibians and delicate plants—all the way up to massive dinosaurs,” Ibrahim says. A few of these fossils represent herbivorous dinosaurs such as the long-necked sauropods. But these creatures don’t seem to be nearly as common as their carnivorous kin, a pattern that paleontologists have noted in sites across northern Africa since the 1930s.

These fearsome beasts included at least four large predatory dinosaurs. One belonged to a group called abelisaurids; its short snout and relatively small teeth suggest it may have been a scavenger. Paleontologists have also unearthed fossils from a Spinosaurus with a narrow snout and teeth specialized for puncturing and snaring fish, a fleet-footed raptor around 26 feet long, and a massive hunter with serrated teeth that resembled steak knives known as Carcharodontosaurus saharicus that was nearly the size of T-rex. Meanwhile, pterosaurs with wingspans between 13 and 20 feet soared overhead and sharks and crocodile-like creatures the length of a school bus prowled the waters.

“If you were to visit this place as a human being, there really are many different ways to die,” Ibrahim says. “You wouldn’t be safe anywhere.”

By examining the broad assortment of fossils from this harrowing environment, Ibrahim says, he and his team hoped to better understand how the “incredible abundance” of predators coexisted and what they dined on. The researchers observed that the skulls belonging to carnivores from the Kem Kem Group varied quite a bit, suggesting they were specialized to feed on different kinds of prey. This might have allowed the predators to stay out of each other’s way and avoid having to compete for the same meals. In many cases, these meals would have been seafood. Fish appear to have been the most plentiful food source at the time, with some of these swimmers reaching the size of SUVs.

In today’s landscapes, top predators such as wolves and lions are well outnumbered by their herbivorous prey. However, even during the mid-Cretaceous Period when northern Africa was covered by vast river systems, ecosystems dominated by so many bulky predators would have been rare. “In some ways it’s more similar to what you might see in marine ecosystems, where predators are actually more common,” Ibrahim says.

The landscape these animals lived in was filled with meandering rivers, lakes, and mudflats. This suggests that the region couldn’t support enough vegetation for long enough periods of time to feed large numbers of plant-eating dinosaurs, Ibrahim says.

However, there may be other reasons why paleontologists have found so few remnants of large herbivores in this area. Most of the sauropod fossils from this region are single bones or isolated fragments rather than more complete skeletons, which makes it hard to determine which species they belonged to, Philip Mannion, a paleontologist at University College London who was not involved in the research, said in an email. Sauropods also tend to have similar-looking teeth, and the vertebrae that would be more revealing are often fragile and less likely to be preserved.

“We can’t ultimately be sure that [the fossils] don’t reflect a greater diversity,” he said. It’s also possible that these plant-eating dinosaurs primarily lived and died in other nearby habitats and only rarely ventured into the areas that happened to be preserved in the Kem Kem Group.

For Ibrahim, the Kem Kem Group is a reminder that the ecosystems of the past could be governed by very different rules from those we see today. This isn’t surprising, he says, given that more than 99 percent of all organisms that ever existed died out before the little slice of time we call the present.

“The Sahara is a breathtaking place as it is, but when you’re out there in this dry and inhospitable place and you pick up giant fish scales and crocodile teeth, that really gives you a sense of what we call deep time,” he says. “That’s when you really understand how much our planet has and can change over time.”

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For millions of years, dinosaurs ruled the land and sky. For whatever reason, though, the ferocious beasts never took the deep dive into the open seas. Sure, some were believed to splash around or wade in prehistoric rivers, not unlike a lizard-like version of today’s grizzly bears. But a full-on marine dino? Until recently, that was the stuff of science fiction—and probably a fish’s worst nightmare.

Back in 2014, a team of scientists led by Nizar Ibrahim of the University of Detroit Mercy discovered a partial fossil of a massive spinosaurus in Morocco. This creature had short back legs, a crocodile-like snout, and pulled-back nostrils, not unlike animals we see with semi-aquatic lifestyles today. These were all hints that this particular dino might have found itself at ease wading into the water, but there wasn’t enough evidence to suggest the animal was a full-time swimmer.

What they really needed to find was the dinosaur’s “motor,” so to speak, which would show how it could navigate at ease for longer periods of time in water. Late last month, the same international crew of scientists published work in the journal Nature, describing the monstrous tail of the spinosaurus, which they believe is evidence to suggest that this guy was a Cretaceous sea monster.

“It’s like the dinosaur equivalent of Jaws,” Ibrahim says.

The scientists recreated a model of the massive tail, which makes the dinosaur itself about as big as a school bus. The enormous appendage acts as a side-to-side swinging paddle, which can propel the monstrous animal powerfully through the water, Cretaceous fish beware. With a motor like that, the spinosaurus was able to spend quite a bit of its time in the water, versus an occasional dip.

For the past several decades, scientists have primarily stuck to the idea that dinosaurs were terrestrial creatures. They could take over all sorts of environments on earth, and even take to the sky. Still, their one great weakness was their inability to “invade the watery world,” Ibrahim says.

Now that paleontologists have discovered that at least this one dinosaur likely lived a watery double life, Ibrahim believes there might be others out there that were more seafaring than we’ve previously given them credit for. Though, it doesn’t necessarily mean that a whole load of different species of dinos were secretly swimming around. Steve Brussate, a paleontologist at the University of Edinburgh, still thinks that the idea that most dinosaurs probably were more comfortable wandering around on dry land holds water.

“No doubt spinosaurus was an able swimmer in shallow waters, but its fossils are also found inland, so it probably was comfortable on land and in water,” he said. “We should be cautious about inferring too much beyond this one species, however.” The oceans were still dominated by other marine animals like sharks, rays, and aquatic reptiles like mosasaurs.

Matt Lamanna, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh, says this new evidence provides a compelling case that the spinosaurus was probably far more aquatic than the rest of the dinosaurs we know about. However, it’s still a mystery how water-loving they actually were. Without a time machine or a real-life Jurassic Park, we’ll never know for sure how any dinosaur lived it’s life. But maybe, Lamanna argues, scientists have swung too hard in the direction of dinosaurs being exclusively land-lovers. If there are more aquatic species out there than we realize, “they’re probably sitting right under our noses.”

Whether or not dinosaurs ruled the seas like giant whales do today is still unknown. But this discovery does act as a reminder that there are still many secrets that can be uncovered in the dinosaur bones still buried beneath the earth, or even the ones on display in museums.

Soon, the dinosaur model will be on display in Bavaria, in the same museum where the first spinosaurus fossil was destroyed amid World War II. Until then, we can just keep hoping that Animal Crossing updates their spinosaurus fossil so we can gawk at its majestic paddle tail from home.

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Scientists announced on Wednesday the discovery of a new long-necked dinosaur with a dazzlingly cute (and, let’s be honest, a very PR-friendly) feature: its tailbones were shaped like hearts. But the discovery is more than skin-deep—the new dino could help paleontologists decipher how a larger group of dinosaurs called titanosaurs came to thrive on every continent on Earth during the Cretaceous Period.

The new dinosaur’s name is Mnyamawamtuka moyowamkia, which is Swahili for “animal of the Mtuka with a heart-shaped tail.” Mtuka is the Tanzanian riverbed from which the fossils were unearthed. Eric Gorscak, lead study author and paleontologist at Midwestern University, chose the moniker, and was very pleased to give the dinosaur a name with roots in Tanzania’s official language.

Moyowamkia bones were first excavated from Mtuka way back in 2004, a time when George W. Bush was president and Friends was still on the air. It took years to complete the fossil dig—the team would walk the dry riverbed, looking for spaces and protrusions in its walls that could signify fossilized dinosaurs. And even after they dug up everything they wanted to, it took years to analyze it all. They had to separate the fossils from the plain old rock they were embedded in, figure out which bone corresponded to which species, and also make sure a set of bones belonged to one dinosaur and not multiple. In other words, they had to “make sure the dinosaur didn’t have two left feet,” says Gorscak, who did the work while at Ohio University. “And then, of course, we do have responsibilities and lives,” he adds with a chuckle.

But the result definitely seems to be worth the almost 15 years of work they put in: a nearly complete skeleton of a new titanosaur, a group of dinosaurs known for their enormous size (the biggest to ever walk the earth), long necks and tails, and teeny, tiny heads. The team definitely knew moyowamkia was a new species because of its lovely, February-appropriate tailbones, as they note in their study published Wednesday in Plos One, along with the sizes and shapes of a few neck and chest bones. Gorscak says the team isn’t sure what function the heart-shaped bones might’ve had, but they look similar to the tail bones of one or two other titanosaurs. Ideally, piecing together how titanosaurs may have been related in this way could uncover some secrets of their evolution.

And while a new dinosaur discovery is inherently exciting, a new titanosaur from Africa is a big deal.

“Titanosaurs dominated Cretaceous ecosystems all over the world at the end of the age of dinosaurs,” says Kristina Curry Rogers, a paleontologist at Macalester College who wasn’t involved with the new study. “In spite of the fact that titanosaurs are being discovered at an astonishing pace and inhabited every continent on earth, the earliest phases of their take over are still pretty mysterious.”

But she says Africa is a “geographic blank space” when it comes to titanosaur discoveries, with just a small handful of exceptions. (Titanosaurs have turned up in Malawi and the Middle East.) That’s why discoveries like moyowamkia are crucial—they “are beginning to clarify what makes titanosaurs so special,” Rogers says.

In the future, Gorscak wants to check out other areas in Africa for evidence of titanosaurs and the animals that lived with them. “I want to go to Malawi next and start looking for whatever else is over there—anything and everything, big and small,” he says. “It’d be a nice springboard. And it goes beyond just titanosaurs. We want a full idea of what these prehistoric ecosystems were like.”

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A series of bite marks on fossilized bones from present-day Colorado reveal that the Jurassic dinosaur Allosaurus was not above eating members of its own species. The findings are the first direct evidence of cannibalism for this group of predatory dinosaurs, paleontologists reported May 27 in the journal PLoS ONE. The researchers also found that fossils collected from the Mygatt-Moore Quarry, which lies near the border between Colorado and Utah and dates back to around 150 million years ago, bore an unusually high number of bite marks. This may mean that Allosaurus and its neighbors were living under difficult conditions and were forced to scavenge any scrap of food they could find.

“At this site they’re eating every single bit of the skeleton, anything they could get their mouth around,” says Stephanie Drumheller, a paleontologist at the University of Tennessee in Knoxville and coauthor of the new findings. “At least under certain circumstances, these big Jurassic theropods were perfectly willing to scavenge anything that was available, including each other, and they were accessing bones as a food resource.”

She and her team examined more than 2,300 fossils excavated from the Mygatt-Moore Quarry over a timespan of more than three decades. Typically, bones with bite marks left by predatory dinosaurs or scavengers are a rare find at sites like this. These scores and gouges can reveal a lot about ancient ecosystems, though. “Bite marks are direct evidence of an interaction—a snapshot in time,” Drumheller says. “We can use these bite marks to figure out who was eating whom [and] specific feeding behaviors.”

Some researchers think that dinosaurs from this era preferred to munch on soft tissues and mostly ignored bones, which would explain why bite marks are so rarely seen on fossils dated to that time. If so, dinosaurs would resemble present-day Komodo dragons—which occasionally nick bones while dining on their prey’s flesh—rather than animals that regularly smash or crunch bones into pieces and eat the marrow inside, such as hyenas and crocodiles.

The new findings also indicate that predatory dinosaurs may have paid more attention to bones than we previously understood. Drumheller and her colleagues found bite marks on nearly 29 percent of the bones from the Mygatt-Moore Quarry, a proportion that, she says, “is off the charts for what you’d expect at a site like this.”

Some of the bones were subtly pitted, while others were profoundly damaged by deep punctures and furrows. In some cases the marked bones—particularly those that came from herbivorous dinosaurs—corresponded to body parts that hungry dinos would typically feast on, such as the thigh or organs. But many of the gnawed-on bones belonged to carnivorous dinosaurs, and those bones tended to come from some unexpected places like the spine and toes, which don’t have a lot of meat on them.

“Predators are lazy and they will typically go for the easiest food first,” Drumheller says. “If all you’re chewing on are toe bones, you’re probably really late to the party and somebody else ate all the nice stuff first and this is all that’s left behind.”

During the Jurassic Period, Colorado was not an easy place to make a living. The region was periodically ravaged by major wildfires and droughts. During the dry season, food may have been very scarce, leaving large predators like Allosaurus with fewer plant-eating dinosaurs to hunt down. In order to sustain themselves, they might have relied on carcasses that had already been picked over by other animals.

Another possibility is that scavenging was a routine part of these dinosaurs’ lifestyle. “Maybe what we’re seeing at Mygatt-Moore is actually normal, but our collection practices have led us to think it’s not,” Drumheller says. It’s uncommon for researchers to bring back every battered and broken fragment of bone they find at a site for museum collections. In recent years, however, paleontologists who work on the Mygatt-Moore Quarry have shifted to collecting all the fossils they discover in bulk. This bounty of bones might offer a fuller picture of what dinosaurs from this site were eating.

Based on the size and type of marks left on the bones, Drumheller and her colleagues were also able to infer that most of the marks appear to have been created by the serrated, steak-knife-like teeth of Allosaurus. In some cases, much to the researchers’ surprise, the damaged bones also belonged to an Allosaurus.

“They were probably opportunistic predators that would eat whatever they could,” Drumheller says. “They weren’t very picky; if it happened to be a distant relation, then that was fine.”

While cannibalism is not uncommon among modern predatory animals, it’s extremely rare to find signs of it preserved in fossils. Paleontologists only have compelling evidence of cannibalism occurring in two other large dinosaurs, one of which is Tyrannosaurus rex.

The Allosaurus bones that Drumheller’s team examined show no signs of healing, which might be expected if the dinosaurs had instead been injured in a fight with other members of their species. “The lack of healing at the tooth marks indicates that these bites all occurred either very near to death or afterwards,” Matthew McLain, a paleontologist at The Master’s University in Santa Clarita, California who was not involved in the research, said in an email. “Bite marks in places that could only be reached after death indicate that some of the carnivorous dinosaurs were actually eating each other.”

McLain, who has done research describing a young Tyrannosaurus that was likely fed upon by a larger peer, added, “It’s likely that some of these tooth-marked Allosaurus bones were bitten by other Allosaurus, which is good evidence for cannibalism.”

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A mummified armored dinosaur found in present-day Canada is giving paleontologists a peak into the eating habits of herbivores that lived 110 million years ago. Fossilized plants preserved in the carcass’s belly reveal that it was dining on a fresh crop of ferns that sprung up after a fire. The soccer ball-sized mass was full of a select few varieties of ferns with traces of charcoal mixed in. Researchers surmise that the dinosaur was a choosy eater and that forest fires might have played an important role in its lifestyle.

It’s incredibly rare for a dinosaur’s last meal to be so well preserved, says Caleb Brown, a paleontologist at the Royal Tyrrell Museum in Drumheller, Alberta who published the findings June 2 in the journal Royal Society Open Science. “We finally have some really good, definitive evidence about what at least one particular animal was eating,” he says. “This is by far the best evidence of diet for an herbivorous dinosaur.”

The dinosaur that Brown and his colleagues examined was discovered in a mine in northern Alberta in 2011. It belonged to the nodosaur family, which in turn was part of a larger group called ankylosaurs. Like its iconic relative Ankylosaurus, this dinosaur was covered in bony plates. It also had a large spine protruding from each shoulder and trundled along slowly on short legs. “They’re very squat, round animals—basically the dinosaur equivalent of a tank,” Brown says.

This particular specimen would have weighed at least a ton-and-a-half while alive and reached 18 feet in length. It probably lived along a coastline during the Cretaceous Period before dying suddenly and being swept out to sea. There it sank to be buried deeply in mud on the seafloor, protected from storms and scavengers. A tomb of brittle rock formed around the carcass, sealing it off from the outside world and preserving features that otherwise would have rotted away. When Brown’s colleagues excavated the remains, they found skin and keratin as well as fossilized bones. The team reported their initial description of the nodosaur, which they named Borealopelta markmitchelli, in 2017.

For the new study, the group turned their attention to the nodosaur’s stomach contents. When they examined small slices under the microscope, the researchers saw “beautifully preserved” plant fragments that included leaves, bits of stem, and charcoal from burnt wood, Brown says. Based on the maturity of the plant tissues, the team concluded that the dinosaur died in late spring to mid-summer, which would have been the middle of the growing season.

Brown and his colleagues observed that about 85 percent of the leafy fragments in the dinosaur’s belly represented several types of ferns. “What is surprising is some of the stuff that’s not there,” he says. Some common plants like horsetails were completely absent, while foliage from cycads and coniferous trees that dominated the landscape were present only in very small amounts. The nodosaur may have preferred certain kinds of ferns over others, munching on these favorites while ignoring the rest.

The remains were discovered in an ancient seabed, removed from the dinosaur’s natural habitat. However, the researchers knew which plants would probably have been most common based on fossilized vegetation from other nearby sites. This gave them a sense of which plants the nodosaur might have encountered but chose not to eat.

The presence of charcoal indicates that a forest fire had recently swept over the landscape. As vegetation began to return, the short young plants would have been easy for the squat nodosaur to reach. “The thing about that regrowth is that it’s more nutritious and easier to digest than the old, mature growth from any of these plants,” Brown says. “If you’re an ankylosaur…the best place to be is an area that’s recently been burned up by a fire where all these ferns are coming back.”

Today, many large grazing animals—including elk, deer, zebras, wildebeests, and other denizens of forests and savannas—seek out areas that have recently been scorched. “This might be the first evidence of dinosaurs taking advantage of forest fires as part of their ecology,” Brown says. “We know that forest fires were quite common during that time, but we’ve never really considered that the forest fire…might actually be a very important aspect of how they made a living.”

However, he adds, there’s only so much that scientists can infer from one carcass’s stomach contents. The food was consumed by a single dinosaur over a matter of hours and may not represent the nodosaur’s typical diet. However, if scientists find charcoal in the stomach contents of other dinosaurs that browsed close to the ground, it would lend support to the idea that these herbivores thrived in forests that were recovering from wildfires.

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About 237 million years ago, a tiny, bug-eating reptile hopped along the sandy riverbanks of present-day Madagascar. Standing about 4 inches tall at the hip, this little creature lived just a few million years before the advent of dinosaurs and pterosaurs—the largest animals ever to walk the land or take to the skies. Its petite stature suggests that dinosaurs and pterosaurs may also have had very humble beginnings.

“Their early history is very mysterious because there are very few fossils,” says Christian Kammerer, a paleontologist at the North Carolina Museum of Natural Sciences in Raleigh, who reported the ancient reptile’s discovery on July 6 in Proceedings of the National Academy of Sciences. “Looking at body size evolution in the group, we find good evidence that the common ancestor of dinosaurs and pterosaurs…would have [had a] very small body size.”

Kammerer and his colleagues named the little reptile Kongonaphon kely, which is derived from Malagasy and ancient Greek words that mean “tiny bug slayer.” Kongonaphon belonged to a group called Ornithodira, which also includes dinosaurs, pterosaurs, and their descendants. 

Among the pieces of the partial skeleton that Kammerer’s team identified were an upper jawbone and bones from the arm, leg, foot, and tail. Kongonaphon’s teeth are small and cone-shaped and lack the serrations seen in the steak knife-shaped teeth that belonged to larger predators. Instead, they resemble the teeth that you’d find today in small, insect-eating lizards.

“By looking at wear on teeth you can tell what fossil animals were eating, and that also matches up with an insectivorous diet,” Kammerer says. “We expect this was a small, very light-bodied predator of invertebrates, mostly insects, [that was] probably running around—maybe hopping around—in its environment.”

The researchers also examined fine slices of Kongonaphon’s shinbone under the microscope. Like trees, dinosaur bones contain growth rings that can be used to estimate age. Kammerer’s team determined that the Kongonaphon was at least two years old when it died and was no longer growing rapidly, suggesting that it had reached maturity.

The Kongonaphon’s right thighbone was missing one tip but probably measured about 1.57 inches in length. Thighbones are one of the main sources of support for the skeleton, which means they can be used to gauge an animal’s total body size. It’s possible that pocket sized ornithodirans like Kongonaphon were common during the Triassic Period, but their tiny bones were rarely preserved as fossils. “Larger bones are less likely to be totally destroyed by scavengers or torn apart by the elements before they get buried,” Kammerer says.

Kammerer and his colleagues also examined how body size may have evolved over time in ornithodirans and other reptiles. While Kongonaphon was probably not a direct ancestor of dinosaurs, its small size is part of a larger trend that indicates that ornithodirans became smaller shortly before dinosaurs and pterosaurs emerged. Their small size and insectivorous diet may have allowed them to avoid competing with the ancestors of mammals and much larger reptiles, which dined on plants and larger animals.

Becoming smaller may have also prepared ornithodirans for the evolution of flight. “All of the flying or even gliding animals start out fairly small,” Kammerer says. It’s even possible that downsizing was related to the emergence of feathers and similar fuzzy coverings, he adds. Small animals lose heat quickly, and these fuzzy coverings may have first evolved to insulate early ornithodirans such as Kongonaphon.

“Some sort of shaggy covering becomes a necessary way to survive while also being able to take advantage of the ecological benefits of being a small animal,” Kammerer says.

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Penguins can’t fly, but they are master swimmers, cutting through the water with ease.

But they aren’t the first animals to develop their sleek swimming technique. It turns out that plesiosaurs, marine reptiles that lived at the same time as dinosaurs (so between 200 million and 66 million years ago), used a similar method to get around in their watery environs.

In a study published in PLOS Computational Biology, researchers created a computer model of how the huge reptile moved. Plesiosaurs grew to be between 8 and 46 feet long, and all had four flippers. The researchers were surprised to find that the most efficient way of moving such a large body through the water was for the plesiosaur to use just its front two flippers, just like a penguin uses its wings.

“Plesiosaur swimming has remained a mystery for almost 200 years, so it was exciting to see the plesiosaur come alive on the computer screen,” Adam Smith, a paleontologist who worked on the paper said in a statement.

See their computer models in the animation below:

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There are very few people in this world that can say they’ve touched a dinosaur skull, much less owned one. For a few years, actor Nicolas Cage was one of those rarified people rich enough to own a dinosaur skull that cost as much as a house.

The story goes like this. Nicolas Cage was, until recently, the owner of a Tyrannosaurus bataar skull, which he paid $276,000 for in an anonymous auction eight years ago. But a recent investigation found that that skull and several other fossils had been stolen from Mongolia’s Gobi desert. Cage immediately agreed to turn over the skull to the federal government upon learning that it was stolen.

Mongolia has been struggling to get back numerous rare dinosaur fossils for years now. Last year one fossil dealer, Erik Prokopi was sentenced to three months in prison for illegally transporting and selling dinosaur fossils from Mongolia in the United States. Excavating artifacts or fossils for profit is a huge concern for the archeological and paleontological communities respectively. Without knowing where they came from, what position they were in, or in what layer of the Earth the items were found strips them of their context as well as their scientific value.

We imagine that Cage went through several emotions on hearing that his prized posession (he is rumored to have outbid Leonardo DiCaprio for the skull in 2007). At first he was probably annoyed:

Then sad:

Then devastated:

Wouldn’t you be, if you had to give up a dinosaur skull? But ultimately, he did the right thing. Returning a country’s National Treasure IRL? That’s something to smile about.

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Dinosaurs ruled the world for over 180 million years, spreading across the oceans and continents. After all that time, it stands to reason that they left a few things behind. We’ve all seen fossils in books and museums, but dinosaurs left behind far more than just their bones. They also left their footprints.

Even though we generally think of footprints as ephemeral, in the right conditions, footprints can be preserved for an extraordinarily long time, even millions of years. Preserved footprints give paleontologists details that fossils alone can’t. By looking at the sediments or rocks where the footprints are located, researchers can get an idea of what kind of environment the dinosaurs were living in. By looking at their size and depth, they can get a better idea of how big or small the dinosaur was, even without any remaining flesh. Looking at how different tracks of footprints overlaps can even tell scientists how different species of dinosaurs interacted with each other. And looking at the spacing between footprints, scientists can figure out how fast the dinosaurs were going when they walked the Earth those many years ago. Looking at how different tracks of footprints overlaps can even tell scientists how different species of dinosaurs interacted.

In a paper published today in Scottish Journal of Geology researchers from the University of Edinburgh announced the discovery of dinosaur footprints along an ancient marsh now in the Isle of Skye, Scotland’s largest island. The tracks were made by long-necked sauropods wandering around 170 million years ago, nearly 50 feet long and weighing 10 tons. The footprints themselves are huge, over two feet across.

Skye Footprints

The fact that the footprints are found in lagoon-type sediments provides more evidence that these animals were not purely land-dwellers as previously assumed. Why these huge dinosaurs liked hanging out in water-logged environments remains to be determined. In the paper, the authors suggest that there might have been more plants available in those environments, or, alternatively, the marshy ground might have been a deterrent to predators.

“The new tracksite from Skye is one of the most remarkable dinosaur discoveries ever made in Scotland. There are so many tracks crossing each other that it looks like a dinosaur disco preserved in stone. By following the tracks you can walk with these dinosaurs as they waded through a lagoon 170 million years ago, when Scotland was so much warmer than today.” Steve Brusatte, the lead author of the study said in a statement.

If you can’t make it out to Skye to see the dinosaur footprints, look for some trackways closer to home. Dinosaur Valley State Park in Texas, Dinosaur State Park in Connecticut, and many other locations around the world have a variety of dinosaur tracks that are well preserved and ready for a visit.

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From Tyrannosaurus rex to Stegosaurus, some dinosaurs are household names. But have you ever heard of Lingwulong shenqi or Caihong juji? If not, it’s probably because these two dinosaurs were discovered in recent years, and their names are in Mandarin.

Dinosaurs are named by the person who discovers the creature, says Mark Norell, a paleontologist who studies fossils at the American Museum of Natural History. The New York museum is home of the world’s largest collection of dinosaur remains.

“The first person to describe a new dinosaur or any animal, plant, fungi species gets to name it anything they want,” Norell says.

Though dinosaurs—a group of reptiles that once lived on and dominated Earth starting around 245 million years ago—mostly went extinct about 66 million years ago, scientists have learned a lot about these creatures through fossils. Fossils are imprints left behind on rocks.

And as scientists find these fossils, they give them names so that they can be identified across all future research. Dinosaur names must abide by the International Code of Zoological Nomenclature, a general set of rules that governs scientific names for all organisms, but there are no major rules as to what their names have to be.

Dinosaurs are often named for their appearance or characteristics, but sometimes also after the scientist who discovered the dinosaur, a place, or a mythical animal.

In the 19th century, the early days of dinosaur discovery, dinosaurs were named by Americans and Europeans using Greek or Latin roots to describe them vividly, Norell says.

In 1841, Sir Richard Owen, an English biologist and paleontologist, came up with the name “dinosaur” to describe the extinct reptile fossils. The name comes from the Greek words “deinos,” meaning terrible, and “sauros,” meaning lizard.

Micropachycephalosaurus, which has a dome-shaped head, means “little thick-headed lizard.” And the best known of them all, Tyrannosaurus rex, was discovered in South Dakota in 1892. The name means tyrant lizard king. Maiasaura, on the other hand, means “good mother.” It got its name when the researcher who found it, Jack Horner, found evidence that the dinosaur would chew up plants to feed its newly hatched babies who couldn’t leave their nest.

But nowadays dinosaur names are much more multicultural since excavations happen all around the world. Now, names are often in local dialects to represent the place where they’re found, Norell says.

For example, in 2004, Norell excavated a small dinosaur in northern China. The dinosaur fossil was discovered in a birdlike sleeping pose, and this gave way to the name Mei Long, a Mandarin name that translates to “soundly sleeping dragon.”

What’s interesting, Norell says, is that new species are being found all the time. About 1,200 extinct dinosaurs have been discovered and named throughout history, and about 50 new dinosaurs are named each year.

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From feathers to flight, researchers keep finding more and more ways that dinosaurs were similar to modern birds. Modern birds are technically living dinosaurs, but a lot could have changed in the 65 million years since the other dinosaurs went extinct.

Now, there’s another similarity to add to the mix: foreplay. In a paper published today in Scientific Reports, researchers found evidence that dinosaurs had mating rituals much like modern birds.

Some male birds today use displays to attract a mate, such as digging or furnishing nests to show how they would provide a safe and impressive home for their offspring. Researchers found evidence in Colorado that dinosaurs did the same thing, scraping the ground to create nest displays, hoping to attract a female to mate with. The ‘scrapes’ are the first of their kind to be found anywhere in the world, and some are as large as bathtubs.

Scrape

The researchers are pretty sure that the scrapes aren’t the remains of actual nests; they aren’t quite the right shape, there aren’t any eggs, eggshells, or evidence of hatching, and they aren’t spaced out as well as other known nest sites.

“The scrape evidence has significant implications,” said Martin Lockley, lead author of the paper. “This is physical evidence of pre-historic foreplay that is very similar to birds today. Modern birds using scrape ceremony courtship usually do so near their final nesting sites. So the fossil scrape evidence offers a tantalizing clue that dinosaurs in ‘heat’ may have gathered here millions of years ago to breed and then nest nearby.”

The scrapes found by Lockley are a kind of trace fossil–fossilized evidence that an organism was there, but not a fossil of the organism itself. Other trace fossils might include burrows, nests, poop, even impressions of urine. Trace fossils like these can give paleontologists insight into dinosaur behavior, like the footprints discovered last year that showed that sauropods liked shallow water.

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About 190 million years ago, during the Early Jurassic Period, a vast desert larger than the Sahara covered much of what is now Utah, Wyoming, Colorado, New Mexico, Arizona, and Nevada. Given that Jurassic time was the “Age of Dinosaurs,” it’s not surprising that fossil evidence of the great reptiles would show up there now and then. But recently, geologists from the University of Utah uncovered an exceptional find — a large concentration of dinosaur tracks and rare tail-drag marks.

Located in the Coyote Buttes North area of the Vermilion Cliffs National Monument, which straddles the Arizona-Utah border, the three-quarter-acre site has more than 1,000, and maybe even thousands, of dinosaur tracks. The tracks were previously believed to be potholes — circular depressions in sandstone caused by erosion — but because of their physical features and the fact that they were concentrated along only one surface, the scientists realized they were actually dinosaur footprints.

The results of the study were published in the October issue of the international paleontology journal Palaios and authored by Marjorie Chan, professor at the University of Utah, and her graduate student, Winston Seiler.

According to Seiler, the variety of track shapes and sizes indicates that at least four dinosaur species were gathered at what he believes was a watering hole in a desert oasis. “The different-size tracks (one to 20 inches long) may tell us that we are seeing mothers walking around with babies,” he said. The 2.4-inch-wide tail-drag marks, some of which are as long as 24 feet, are particularly noteworthy, as there are fewer than a dozen such sites known worldwide, according to Seiler.

The tracks and tail marks were preserved when shifting sand dunes covered the area where the dinosaurs left their prints. Over millions of years, the dunes became the Navajo Sandstone, which is visible today throughout much of the Colorado Plateau region. More than 60 track sites have been found in Navajo Sandstone, but the density of the newly discovered “trample surface” makes it unique.

Dinosaur Track

Coyote Buttes

Dino Trackway

Big Track

Trample Surface

Scenic Byway

Fossil Bones

Petrified Dunes

Waterpocket Fold

Vermilion Cliffs

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When it comes to egg art, modern birds have the market cornered. Turtles and lizards and alligators encase their spawn in plain white, while bird eggs appear in bright blues and browns and speckles galore. For a long time, scientists thought this colorful trait was entirely unique to modern avians. But our winged friends may have inherited this artistic ability directly from dinosaurs.

Colorful eggs evolved only once among dinosaurs, who then passed the trait down to their modern descendants, according to a paper published this week in Nature. Egg color popped up when dinosaurs started nesting above ground, much like many species of modern bird, the scientists found.

“It’s really an important contribution to the literature, it illustrates that the eggshell pigments evolved much earlier than previously thought,” says Daniel Hanley, a behavioral ecologist at Long Island University Post who was not involved with the new study.

Until recently, most scientists thought dinosaur eggs resembled plain old reptile clutches, and birds were the only creatures in evolutionary history with the ability to paint their offspring. In 2015, Jasmina Wiemann, one of the authors on the new study and a molecular paleo-biologist at Yale University, published a study that found traces of blue-green in the eggs of the extremely elegant oviraptors.

Next, Wiemann wanted to know “could egg color have a single evolutionary origin, or did [the trait] evolve two times or more times independently?”

To answer this question, Wiemann and her colleagues at the American Museum of Natural History collected 20 eggshell fragments from dinosaurs around the world as well as alligators and birds including chickens and emus. The scientists only used dinosaur eggs where they could be sure of what species it came from which greatly restricted their sample, says Mark Norell, chairman of the division of paleontology at AMNH and co-author on the new research.

In birds, all egg colors and patterns break down into just two pigments: biliverdin, which makes blue-green, and protoporphyrin IX, which makes brownish red. Wiemann and Norell used a technique called Raman microspectroscopy to find and measure the concentration of small amounts of these pigments in the dinosaur eggs to reconstruct their colors and patterns. This technique is highly sensitive and does not destroy the precious eggshell samples when analyzing them, says Norell.

Then, the scientists mapped each colorful egg onto a dinosaur family (also known as a phylogenetic) tree. They found colorful eggs appeared early in the ancestry of theropod dinosaurs, the family from which modern birds are descended, when dinos stopped burying or covering their eggs, says Norell. The timing suggests the ability to make a pigmented egg evolved only once, “and didn’t evolve near the ancestor of birds, and evolved far deeper in the dinosaur family tree,” Norell says.

Reptiles today bury or cover their unadorned eggs, while scientists think colorful shells likely evolved to protect eggs in exposed nests. Pigmented eggshells might camouflage broods laid in open nests, help birds identify their own young to ward off bird parasitism, filter solar radiation, keep the eggs the right temperature, and block invading bacteria when ultraviolet light excites the brown pigment, says Hanley.

“Once you build an open nest, you have the egg exposed to the environment, exposed to potential predators, to nesting parasites, to parents,” explains Wiemann, “[there’s a] selective pressure that favors the evolution of egg color.”

The eggshell resemblance could mean we can look to the lives of modern birds to “predict dinosaur ecology” in the past, says Hanley. “That would be super cool.”

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He is greenish brown, has dragon scales for skin, grows up to 32 inches and is the world’s last remaining lizard-like reptile that has a lineage dating back to about 225 million years when dinosaurs still roamed the earth—he’s a tuatara and he’s making a comeback. A species native to New Zealand, the tuatara was spotted nesting in a sanctuary close to Wellington last week, the first such sighting in 200 years. Staff at the 620-acre Karori Wildlife Sanctuary stumbled upon four white, leathery ping-pong sized tuatara eggs during routine maintenance work at the end of last week.

Tuatara Eggs

A rare find, the nest is the first concrete proof that tuatara are breeding again, said sanctuary officials of the species that, unlike other reptiles, has two rows of top teeth and a light-sensitive “third eye” on its forehead, which is visible for about six months when it hatches. In an effort to save the species that once flourished in the Mesozoic Era and almost neared extinction in the 1700s because of the introduction of predators like rats, the Karori Sanctuary created 70 tuatara in 2005 and another 130 in 2007, before releasing them into the wild. At the moment, tuatara can only be found living in the wild in 32 offshore islands that have been removed of possible predators.

Sanctuary officials said the eggs were most likely laid a year ago and that there could be more since an average nest usually contains around 10 eggs. If incubated properly, the eggs, which have been left at its original location to avoid any further disturbance, should hatch some time between now and March.

[Via AP]

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The Tyrannosaurus rex was a nightmarish lizard, a menacing meat-eater that chomped down on other dinosaurs like the Triceratops and Edmontosaurus with a bone-crushing bite. They likely even cannibalized members of their own species.

But what about the more than 700 other species of dinosaur that existed millions of years ago? For many of them, meat wasn’t on the menu. They ate salad instead. That’s according to Jordan Mallon, a paleontologist at the Canadian Museum of Nature, who says the vast majority of dinosaurs were actually herbivores, munching on plant matter rather than flesh.

“In any ecosystem, you have more herbivores than carnivores,” Mallon says. This applies to the landscapes of today—there are more deer than, say, wolves—and to ancient ecosystems. During his digs, he says, “I probably see six herbivorous dinosaurs to every one carnivore.”

And surprisingly, the bigger the dinosaurs were, the more likely they were to be vegetarian, he says. Take Sauropods, for example. This long-necked group contains the world’s largest dinosaurs—such as Argentinosaurus, the biggest land animal to have ever roamed the Earth, by some estimates—and they munched on little more than ancient plants like cycads, ferns, and ginkgos. A lot of them.

“They would have had to be shoveling in hundreds of pounds of food a day if not more in order to sustain their metabolisms,” Mallon says of Sauropods. “They were just raking in leaves.”

(Some of them also swallowed stones, which may have aided digestion by grinding up the plant material in their stomachs.)

That’s not to say that plenty of species weren’t feasting on flesh. Predators like Majungasaurus and Allosaurus, Mapusaurus and Giganotosaurus, along with other large carnivores, probably dined on other dinosaurs, Mallon says.

Related: When and how did dinosaurs go extinct?

“Most meat-eating dinosaurs were eating other dinosaurs because they were the dominant animal in the ecosystem … especially for the bigger dinosaurs, which would have only been able to sustain themselves on dinosaur meat,” he says. “Everything else was too small.”

There were, however, some exceptions. The Spinosaurus, easily recognizable by its sail-like spine, is believed to have been the largest carnivorous dinosaur. Yet it was pescatarian.

“We think there were at least a couple of dinosaurs like Spinosaurus that were fish specialists,” says Mark Norell, chairman of the division of paleontology at the American Museum of Natural History. “They had dolphin-like teeth and snouts,” he says, which are perfect for snatching up prehistoric sea creatures.

So if humans were around 70 million years ago, would we have been on the menu, too? Probably. Though it’s impossible to be sure, barring a real-life Jurassic Park, humans would likely be prey. After all, Norell says, carnivorous dinosaurs were not likely picky eaters.

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In the fossil halls of New York’s American Museum of Natural History, visitors take a journey through millennia of life on Earth. In each room, you walk among leviathans of bone. The iconic Tyrannosaurus rex and apatosaurus, followed by ancient mammals—Giant sloths, mastodons and many others. All hulking, all awe-inspiring. But on the fourth floor, starting today, resides a new resident that somehow makes all the others seem small by comparison: the titanosaur.

This specimen, so new it has yet to be named (Titanosaur is the family of dinosaurs it comes from), is one of the largest dinosaurs ever discovered, and one of the largest creatures ever to be displayed in the AMNH. The immense 122-foot-long cast of its skeleton is so long, in fact, that it can’t quite fit into the Ira D. Wallach Orientation Center in which it’s housed. Its head stretches out of the room, almost ten feet off the floor, cocked sideways and peering down upon all who enter with one eye and a big toothy grin. “Hospitably welcoming visitors,” said a smiling museum President Ellen V. Futter at a media preview yesterday.

The gigantic life-size cast is the end product of a journey begun in Argentina in 2014, when scientists there discovered an eight foot long femur weighing over a thousand pounds.

Discovering the Dinosaur

After a tipoff from a local rancher, Paleontologists Diego Pol and Jose Luis Carballido, of the Museo Paleontologico Egidio Feruglio (MEF), carefully excavated 200 fossilized bones from the arid landscape of Argentine Patagonia. The tedious process took several labor intensive expeditions over a period of 18 months to complete and even required partial removal of a hill. Bulldozers and trucks were employed in the removal of earth, hauling of thousand pound bones, and all the other brow wiping labor involved in paleontology. “We actually had to build a road to get there [to the site]” reflected Diego Pol, seated in front of the behemoth before journalists.

Dinosaurs are not lying in the ground in fully intact skeletons patiently waiting to be dug up, but are usually either just a few bony remains or a dizzying mass of bones in a disorganized pile. This dinosaur was discovered in the latter state. What Pol found was a melange of 200 some bones of multiple individuals. But, “For this animal, we have about 70 percent of the skeleton,” remarked Pol, which is most certainly not the norm in the field.

Titanosaur, American Museum of Natural History

A Dinosaur’s Life

As surprising as it may seem, the 122-foot-long titanosaur was actually a juvenile. A 70-ton juvenile at that. This enormous animal was a sauropod, a type of herbivorous dinosaur with extraordinarily long necks and whiplike tails. Titanosaurs are the wider family of gigantic dinosaurs to which this oversized youth belonged.

Although it’s hard to say exactly how this creature lived its daily life, 100 million years ago in the Cretaceous period—much can be inferred from knowledge of other sauropods and existing giant herbivores like elephants. With its size, it’s likely that this titanosaur spent most of its day feeding. Lumbering around with its thick, swaying neck, it raked up tall growing vegetation with giant grinding teeth. Eye crossing numbers of calories would be needed to support a body of such size. “Maybe a thousand pounds of food a day. At least 500,” Mark Norell, Chair and Curator of the Paleontology Division at AMNH told Popular Science. “Elephants eat for 20 hours a day, and they eat plants that are probably more nutritious than the ones that existed when these dinosaurs did.”

Titanosaur, American Museum of Natural History

Paleontologists also have plenty of evidence that—like elephants—sauropods were social animals. This is found in the trackways, or fossilized footprints of these giants that reveal multiple individuals walking together back and forth, not in random patterns. Norell said that they can even tell by these trackways that “some other sauropod groups had structured herds—like elephants do—because you can see that the big adult ones were out in front, and the smaller juvenile ones were in the middle.”

The titanosaur at AMNH likely also roamed the forests of Cretaceous Patagonia in freedom from fear thanks to its immense size. “There were some predators which were about the size of T. Rex, but it’s doubtful that they would’ve had any predators,” said Norell. Standing with him next to the cast it’s easy to see why. Norell added ”only really rarely do you see African lions, which are apex predators in Africa, go after an adult elephant.”

Installing the Titanosaur at the Museum

Building the Dinosaur

Before the fossil bones were even completely out of the ground, Peter May and his team from Research Casting International were down in Argentina taking 3D scans of them. “We scanned all the bones that they had—200 in all,” May told Popular Science. Back in Ontario at their workshop, the team of dinosaur builders, plugged that information into computers and 3D printed out fiberglass casts of the great bones. Or rather, printed some. The printer was actually too small for most of the bones “so the rest were done on the milling machine. 10′ by 6′ by 4′ deep. And we just carve away. Carve right down.”

3D Printer

Once the hollow bones were fitted inside with rigid steel structures, assembling it in New York became just a matter of fastening the modular pieces together. But not without some sweating. Getting the young titanosaur to fit in the gallery took some finagling. “The ceiling [of the hall] is 19 feet 4 inches,” said May, gesturing to the hand sized vertebrae grazing the ceiling, “and the top of the dinosaur’s back is 19 feet 2 inches.” If the shoe fits.

Actual fossils aren’t included in the skeleton because their immense weight precludes them from being able to be mounted. As Norell explained, “The original femur weighs over a thousand pounds, this one weighs about 15.” But although the skeleton doesn’t contain any of the real fossils there are some on display, on loan from MEF in Argentina, including a prodigious eight foot tall femur.

Installing the Titanosaur at the Museum

Standing beneath its towering structure of bones, you can imagine a herd of these titanosaurs trudging through the forests of Patagonia, with smaller creatures scurrying and flying out of their way. Sure to be an instant and icon of the American Museum of Natural History and the city of New York, the titanosaur embodies the lengthy strides of modern science and technology as well as the old fashioned thrill of discovery. As Michael Novacek, the Museum’s Senior Vice President and Provost for Science framed it for the media, “With all this technology, with all this new science…there’s nothing like finding a great new fossil. Especially a big one.”

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Paleontologists have discovered what very well might be the oldest known dinosaur, if in fact Nyasasaurus parringtoni is a dinosaur at all. A study published in the journal Biology Letters is describing a new species of prehistoric reptile that appears to predate the previous earliest-known dinosaur by 10 to 15 million years. That not only stands as a new superlative in dinosaur classification, but if confirmed, it fills a gap in the evolutionary timeline that’s been puzzling scholars for years.

Nyasasaurus parringtoni is a fairly small relative of the massive reptiles we’ve come to associate with the word dinosaurs. Measuring between 6 and 10 feet long, it walked semi-upright on two legs and weighed somewhere in the vicinity of 45 pounds to 130 pounds–a wide range, we know, but considering researchers are working with just one upper arm bone and six vertebrae, all of these figures are assumed to be very rough approximations.

Far more important than precise physical specs is the dinosaur’s age. The early evolution of dinosaurs is kind of tough to parse, particularly because there were a lot of reptiles on Earth at the time, some of which may have evolved dinosaur-like traits independent of the dinosaurs. Discerning the difference using only the fossil record as a guide is difficult, but the researchers authoring the paper maintain that a few of the features they have extrapolated from their skeletal specimens suggest very strongly that it is indeed a dinosaur–and the earliest one yet discovered.

If they are correct, Nyasasaurus parringtoni would fit right into a hole in the evolutionary chain of events, dating to right around the time paleontologists think dinosaurs split off from their oldest relatives and became the distinct group that would later go on to dominate the Earth for 100 million years. That means that perhaps Nyasasaurus parringtoni is the oldest dinosaur ever discovered, or maybe that it’s not (the research team itself has stopped short of formally making that claim based on the incompleteness of the skeleton, though the evidence they put forth suggests that it is). Either way, the species is a key piece in the puzzle of dinosaur evolution, one that would’ve shared the planet with dinosaurs’ oldest known relatives and that very well may have kicked off the age of the dinosaurs.

BBC

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Four scientists are now disputing the recent discovery of rare dinosaur tracks in a remote area near the Utah-Arizona border. According to the original study, which was published in the October issue of the paleontology journal Palaios and widely reported around the world, a large concentration of dinosaur tracks and rare tail-drag marks was found in a dinosaur “trample surface” in the Vermilion Cliffs National Monument. But Brent Breithaupt of the University of Wyoming Geological Museum, Alan Titus and Rody Cox of the U.S. Bureau of Land Management, and Andrew Milner of St. George Dinosaur Discovery Site at Johnson Farm believe the dinosaur tracks are actually just sandstone potholes, created by erosion and weathering.

Millions of years ago, shifting sand dunes covered much of the western U.S. Over time, the sand dunes became the Navajo Sandstone rock, which is visible throughout much of the Colorado Plateau region today. Potholes are circular depressions in the sandstone carved by erosional processes, such as when pebbles or sand swirl in running water. They can look deceivingly like dinosaur footprints, which makes life complicated for scientists.

In their published findings about the discovery, University of Utah professor Marjorie Chan and graduate student Winston Seiler acknowledged that there are strong arguments for the features being potholes and not dinosaur tracks. In fact, the University of Utah press release on October 20, 2008 that announced the findings disclosed that one reviewer of the Palaios paper believed that the holes were erosion features. But because the holes exhibited many footprint features, and because they were concentrated along only one surface, Chan and Seiler argued that the impressions were made by dinosaurs.

Now, the two investigators have agreed to collaborate on a follow-up study with the four scientists who question the findings. “We gave the project considerable critical thought and came up with a different interpretation than the paleontologists,” said Chan. “But we are open to dialogue and look forward to collaborating to resolve the controversy.”

Debates over research findings and results are not unusual in the science world; in fact, according to the scientific method, results and findings must be reproduced by others in the scientific community to be confirmed. Seiler, whose master’s thesis work was based on the dinosaur tracks discovery, fully acknowledges that his interpretation is controversial and that further study is warranted, saying that if the paleontologists’ skepticism turns out to be justified, “that’s part of science.”

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You can find all kinds of things on a beach. Lost sunglasses, loose change, seashells, the fossilized remains of a dinosaur. You know, the usual.

In 2014, fossil hunters found the remains of a dinosaur on a rocky Welsh beach after a storm. They turned the fossil over to National Museum Cardiff, where researchers from the museum and UK universities identified it as a theropod, a relative of Tyrannosaurus rex.

In a paper published this week in PLOS One, researchers announced that further work on the fossil led them to conclude that this dinosaur, named Dracoraptor hanigani, lived 200 million years ago and was one of the earliest dinosaurs of the Jurassic period. It’s also the first Jurassic-era dinosaur skeleton found in the UK.

Why is it exciting that the dinosaur is 200 million years old? There are certainly other, older fossils of dinosaurs out there, dating back into the Triassic period 240 million years ago. But this new dinosaur fossil lived right on the boundary between the Triassic and Jurassic, a line in time that paleontologists are still trying to learn more about.

See, dinosaurs lived during a geologic era called the Mesozoic, which lasted from 250 million years ago to around 65 million years ago, when the dinosaurs went extinct. The Mesozoic is broken into three periods: the Triassic (250 million to 199.6 million years ago), the Jurassic (199.6 million to 145.5 million years ago), and the Cretaceous (145.5 million to 65.5 million years ago). The divisions between these periods are marked by changes in lifeforms and climate, most notably extinctions.

Early dinosaurs evolved in the Triassic, but they didn’t come into their own until the Jurassic, after a huge extinction event that wiped out massive amounts of marine creatures. The cause of the extinction remains unknown, but researchers are always eager to know more about the lifeforms that did manage to survive, or evolved right after an event like this.

Researchers already know a lot about Dracoraptor hanigani. It was a small dinosaur, just 2.3 feet tall, and 6.5 feet long (including its long tail). With bones that were still growing it was possibly a juvenile, and likely was warm-blooded with feathers.

“The Triassic-Jurassic extinction event is often credited for the later success of dinosaurs through the Jurassic and Cretaceous, but previously we knew very little about dinosaurs at the start of this diversification and rise to dominance,” said co-author Steven Vidovic. “Now we have Dracoraptor, a relatively complete two meter long juvenile theropod from the very earliest days of the Jurassic in Wales.”

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Birds: They’re just like us. Except their lungs are small in comparison to their body size (much smaller than ours, by this metric) and they have a set of air sacs, nine in total, that run down the sides of their bodies.

A newly described fossil found in China shows that birds evolved one of these notable features very, very early–while they were still dinosaurs, in fact. A team of researchers from China and South Africa just published a study detailing the presence of what they believe to be lung tissue in the fossil. This is the first time evidence of lungs has been found in an avian dinosaur fossil, and it may help explain why one group of avian dinosaurs—the Ornithumorpha, of which this fossil was a member—was able to survive the extinction event that killed the dinosaurs and continue to evolve into modern birds.

The finding “just reinforces the idea that this group was more highly evolved than other Cretaceous avian lineages,” writes paleontologist Jingmai O’Connor of the Chinese Academy of Sciences in an email to Popular Science. O’Connor and her team observed a “speckled white material” in the fossil, according to the paper, and by employing scanning electron microscopy (a specialized type of microscope), were able to study both the material and its location within the skeleton. They believe it’s evidence of lungs, part of the morphological sophistication that may have allowed one lineage of Ornithumorphs to survive the great extinction and evolve into birds.

Modern birds have “structurally the most complex, and functionally the most efficient” respiratory system among vertebrates, according to the paper, published in the Proceedings of the National Academy of Scientists. The system of lungs and air sacs means that birds are able to take in much more fresh, oxygenated air with each breath than we mammals can, since even a full breath in our lungs has “old” air that’s depleted of oxygen within it. Imagine birds as really good athletes with great lung capacity–which they are, since flying everywhere takes tons of energy and requires a high metabolism.

But back in the Cretaceous Period, the last one in the age of dinosaurs, there were lots of other kinds of avian dinosaurs. When the Archaeorhynchus spathula specimen documented in the new paper was alive in the Lower Cretaceous Period, it might have shared the skies over the fossil-rich Jiufotang Formation with whole groups of avian dinosaurs who didn’t make it, says Matthew Lamanna, assistant curator of vertebrate paleontology at Carnegie Mellon.

What precisely set the Ornithumorphs apart remains a mystery, says Lamanna, who was not involved in the current study. “Why that particular group survived is a very, very interesting question,” he says, “and one we don’t have a good answer for at this point.”

This new find suggests that maybe vascular efficiency is part of the answer. When he heard about the discovery, Lamanna says, “I was basically like, holy shit, fossilized lungs in a bird from 120 million years ago. That’s really, really cool.” The process of fossilization usually destroys soft tissue—but not always, and maybe not even quite as often as previously thought, he says. It may even be the case that some of the fossils currently held in museum and research collections have evidence of preserved soft tissue that could help explain how the dinosaurs lived in a way that bones cannot, he says. He believes this new paper, which was presented yesterday at the Society of Vertebrate Paleontology’s annual meeting, might help push curators to return to their existing collection with new questions.

“The way soft tissue preservation is changing the field of paleontology is really important,” says O’Connor. “It is revolutionizing how we interpret skeletal remains.” What paleontologists think based on just the skeleton is “more often than not wrong” when it comes to reconstructing organ systems, she says.

In the absence of soft tissue evidence, paleontologists have traditionally made guesses about organs based on fossilized bones and the dinosaurs’ closest modern descendants, the crocodilians and the birds. But there might be more soft tissue out there than the field currently knows—not just in new finds like this one from China. Occasionally, Lamanna says, paleontologists take a new look at old evidence and discover “that these structures were there all along.”

“If we are not looking, we most likely will not see it,” writes O’Connor. She also thinks that if paleontologists look closer, there is more soft tissue evidence to be found than previously believed.

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An ostrich-like dinosaur known as an ornithomimid would probably yield the most consumer-friendly cut of meat, while still maintaining a unique dinosaur taste.

Much of the flavor in a cut of meat comes from its fat composition, and an animal’s diet contributes significantly to this. However, due to the average consumer’s taste for meat that is not too strong-tasting, it is more important to figure out what we don’t want the animals we consume to be eating. Dinosaurs that ate marine animals would definitely be off the list, not only for their fishy flavor, but also because the high amount of oil in fish would make the meat more susceptible to oxidation, which would give it a rancid taste. In fact, any carnivorous dinosaur would not fare too well in the supermarket. Most people prefer meat that comes from herbivorous animals—think cow, deer, bison— since animal fat found in a carnivore’s diet adds a significant amount of “gamey” flavor. And some dinosaurs’ diets are far too unappetizing to consider.

“When people ask me if a T-Rex would be good, well, I don’t think so,” David Varricchio, professor of paleontology at Montana State University, says. “They’ve found jaw abnormalities that suggests they were eating fetid meat and had diseases that came about from prey items. They would be pretty parasite-laden.”

Just as important in the search for the best cut of dinosaur meat would be the level and type of activity for which the dinosaur was built.

As for exactly which dinosaur would be most appetizing, one with red meat would have just enough flavor as compared to one with blander white meat. Theories that dinosaurs would have tasted like chicken abound since dinosaurs are so closely related to birds, but for many land-dwelling dinosaurs, beef may be a closer guess. The kind of activity an animal does determines what kind of meat it yields. Red meat is composed of slow-twitch muscle fibers, which are built for sustained periods of activity, so animals that are active for longer amounts of time throughout the day would be composed of mostly red meat. Those who ambush their prey or move quickly for short periods of time would have white meat, which is composed of fast-twitch muscles that allow for quick bursts of activity. So dinosaurs taking part in extended periods of activity would probably have muscles less like a chicken (or even a fast-acting predator like a cheetah) and more like a steady-moving cow.

The tasty–yet accessible!–ornithomimid

Ornithomimosaurs were a group of ostrich-like dinosaurs that were part of the suborder Theropoda from which modern birds evolved. They were close enough to birds that they likely had feathers and were warm-blooded, but they were very active animals with large hind legs for prolonged periods of running, so their muscles would probably have been mainly slow-twitch, less like modern birds. Though most theropods were carnivorous, ornithomimids were unique in that they had no teeth, a fact that has led most to believe they ate mostly plant matter.

“About 80 percent of the ornithomimids were hindquarters, and they were really well-suited for running,” Varricchio says. “I’ve also done a little work on their bone histology and it’s safe to say they’re relatively fast-growing. I think it would be a lean, slightly wild-tasting red meat.”

That’s not to say other dinosaurs wouldn’t make a tasty meal either. Velociraptors, being wild ambush predators, may have had gamier-tasting white meat comparable to a carnivorous bird such as a hawk. Taking into consideration activity level and diet could yield a huge variety of possibilities were dinosaurs ever to roam our pastures and grocery stores.

“You could get into cuts of meat. Armored dinosaurs mainly used their tails for defense, so that would probably be a lot of good white meat. Hadrosaurs were quadrupedal and spent much of their time on the move; I suspect they would be largely red meat,” Varricchio says. Sauropods, the largest animals to ever walk the earth, may have made for an interesting meal as well. Their long necks, used to reach high-up food sources, could have resulted in a unique cut of sturdy red meat weighing several tons. Says Varricchio, “Sauropod neck could be a delicacy.”

Florida native Erin Berger is a junior at Northwestern University. She is studying journalism and anthropology with a special interest in health, social justice and, of course, dinosaurs.

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Titanosaur, American Museum of Natural History

In January, the American Museum of Natural History in New York City unveiled its new, 70-ton dinosaur named Titanosaur. And as any good child would do (or, who am I kidding, I do this), AMNH has created an adorable social media personality for its new fossil.

Over on its Tumblr page, AMNH has posted a series of texts between Titanosaur and the museum’s other giant specimen: Blue Whale. “Separated by 3 floors of the Museum, how do these pals stay in touch? They text, of course!” AMNH writes.

Texts from Titanosaur

A nice blend of fact and fiction, you get to know a little more about this giant dino through its texting habits.

Titanosaur is adorably naive sometimes, not knowing that it’s way too big to take the subway or ride a CitiBike. And its Argentinian roots also show through, when it thinks mixes up football and soccer. And like any skilled texter out there, Titanosaur and Blue Whale are masterful at using emojis to talk about food, though maybe the emoji gods should think about creating a dinosaur one, eh?

You can read all of Titanosaur’s and Blue Whale’s texts in part one, part two, and part three. Let’s hope part four keeps things friendly between the two giants.

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Dolphins are great! Intelligent, charming, cute. This newly-discovered dolphin-like predator: maybe not so great.

_Thalattoarchon saurophagis_–meaning “lizard-eating ruler of the sea” (!)–was at least 28 feet long, and spent its 160 million years on Earth eating creatures that were smaller, the same size, and even bigger than itself, before it died out about 90 million years ago, or 25 million years before the end of the dinosaurs. It used a giant skull with giant teeth to prey on those often-giant sea-dwellers.

Researchers, who first discovered fossil evidence of Thalattoarchon in central Nevada in 2008 and published their findings this week, pin the creature’s heyday at about 244 million years ago. That puts it at 8 million years after a mass-extinction killed as many as 96 percent of ocean creatures. It seems, then, that ecosystems restore balance after a major die-off relatively quickly: if predators this size were able to survive by hunting other large creatures, there must’ve been small creatures at the lower end of the food chain, too.

Still, though: tough luck for those species that barely missed mass extinction, then had to deal with this thing.

LiveScience

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All Of the Birds

This gorgeous infographic is the first family tree linking every bird on Earth, revealing how birds have evolved since the dinosaur age.

The map shows where and when birds lived, which offers a glimpse of species diversification around the planet. One big takeaway: Birds have been diversifying at an increasing rate in the past 50 million years. Today, 9,993 living species are known.

This is significant, because it runs counter to a prevailing view in biodiversity circles, the study’s authors say. “A new distinctive group, like bumblebees or tunafish, first evolves, and, if conditions are right, it quickly radiates to produce a large number of species,” says co-author Arne Mooers of Simon Fraser University in Canada. “These species fill up all the available niches, and then there is nowhere to go. Extinction catches up, and things begin to slow down or stall. For birds the pattern is the opposite: Speciation is actually speeding up, not slowing down.”

Another surprise from the data: The greatest diversification is not in the tropics, but in the western hemisphere. Biologists have long thought the tropics would play host to the greatest range of speciation. After all, that’s where you find birds of paradise. But apparently, diversification rates are higher in North America, Eurasia and southern South America.

The authors have a couple ideas about why this is. First is the appearance of key adaptations in species like songbirds, parrots and hummingbirds, leading to diversity as the animals evolve to fit specific niches. Second is a previously unknown radiation among ducks, geese and some gulls. Radiation in this case means adaptive radiation, the evolution of new phenotypes.

To build the family tree, the team relied heavily on fossil and DNA data, in addition to geographical information, according to a news release.

The paper is published this week in Nature.

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Whether it’s fabulous,

or out of this world,

hair matters to humans. Really, to all mammals. Hair and fur bind us all together from the adorable…

…all the way down the cuteness food chain to pizza rat.

As much as we might not like thinking about the ties that bind us to our rodent relatives, our flowing locks and their fur have the same tangled roots. Scientists announced today that they found evidence of hair on a fossilized, 125 million year old rat-like animal. While fossilized evidence of fur had previously been found in older fossils, this well-preserved hair represents the earliest fossil found with defined, individual hair structures, the researchers say.

In a paper published today in Nature, researchers detail the find of the fossilized remains of a creature called Spinolestes xenarthrosus. Spinolestes was about the size of a small possum, or a large rat, and lived in a wetland in what is now the Las Hoyas Quarry in Spain. Spinolestes lived in the ground, ate insects, and probably did its best to avoid the dinosaurs that were tromping around in the area.

This particular specimen was incredibly well-preserved, with far more than just fossilized bones surviving the intervening 125 million years between death and discovery. It also had the remains of an external ear, internal organs, and evidence of hair and hair follicles. Usually such delicate structures don’t survive millions of years under rock and dirt, but occasionally a dead animal will be preserved in such a way that impressions of fur or feathers survive. Often, these aren’t much more than impressions, or textures baked into the rock by time, but in the case of the Spinolestes, individual hairs were fossilized into place by the surrounding rock, and remained preserved overtime. The next oldest (well-preserved) hair remains are 60 million years younger than these.

“With the complex structural features and variation identified in this fossil, we now have conclusive evidence that many fundamental mammalian characteristics were already well-established some 125 million years, in the age of dinosaurs,” co-author of the paper Zhe-Xi Luo said in a statement.

In addition to softer, more fur-like hairs identified in other parts of the body, the researchers found that Spinolestes had a layer of spikes along its back, similar to a hedgehog’s protective spines. They also found, based on the pattern of a section of the fur, that Spinolestes probably had a fungal infection called dermatophytosis, an infection that affects many mammals today. You probably know it as ringworm.

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Cancer follows a fairly standard protocol: Cells multiply out of control until they take over key organs necessary for survival. Creatures across the animal kingdom from humans to birds to reptiles can all get cancer, and, as researchers report this week, so can dinosaurs that roamed the Earth millions of years ago. Knowing more about how and why the mysterious forms in these ancient creatures could help doctors prevent more animals from meeting the same fate.

Scientists from the Royal Ontario Museum and McMaster University have discovered that an ancient triceratops-like beast that lived over 75 million years ago developed an osteosarcoma tumor in its leg bone. They published their new findings in The Lancet last week.

The team of scientists, including health experts and paleontologists, had been searching for human-like diseases in ancient dinos by digging through old fossils at Canada’s Royal Tyrrell Museum and stumbled upon the fibula of a Centrosaurus apertus that had scientists had uncovered in Alberta thirty years ago.

Paleontologists at the time had diagnosed the malformed fossil as an oddly healed fracture. But a new team of researchers took a closer look, examining and running tests as they would if the bone belonged to a human patient. That meant coming up with a list of possible diagnoses, and eventually, biopsying slices of the bone under a microscope to take a closer peek.

“We had to do something called destructive analysis which is exactly what it sounds like,” says Seper Ehktari, an author of the study and orthopedic surgery resident at McMaster University.

With this closer examination, Ehktari and his team realized the destruction of the bone was caused by osteosarcoma which still impacts some 800 to 900 new human patients in the US yearly. Ehktari adds that it’s not only humans that get this disease, but other mammals and creatures more closely related to dinosaurs like chickens and cockatoos.

Jennifer Anne, a paleontologist at the Children’s Museum of Indiana not involved in the study, notes that this is not the first spotting of cancer in dinosaurs. There’s been a handful of known cases (a duck-billed dino has also had signs of bone cancer). However, it does open up a whole new group of dinosaurs to novel discoveries regarding cancer that we might’ve missed before.

“We are also gaining a lot more knowledge about cancer in non-human animals,” Anne says. “That information coupled with better access to new technology like CT scanners that can scan dense fossils means paleontologists are going to get better at identifying and, to the best of their ability, diagnosing paleopathologies.”

Beyond just satisfying our curiosity for the lives of the massive dinosaurs that once roamed our current-day backyards, discovering more about cancers in their ancient forms could help us diagnose and fight them in today’s creatures, including in us humans. Osteosarcomas in humans typically develop when people are growing at a super-fast rate, typically around age 10 to 20, says Ehktari.

Seeing as dinosaurs also grow rapidly from tiny babies to massive beasts is another reinforcement to the theory that rapid growth might have something to do with the rapid reproduction of cells, Ehktari says. After all, he adds, the more cells are growing and reproducing, the more likely it is that a handful of them could “go rogue.”

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When it came to dining on Triceratops, the Tyrannosaurus had a problem. That nutrient-rich meat in the Triceratops neck was a Late Cretaceous delicacy, but with that huge bone and keratin frill in the way it was notoriously difficult to get to. Now, paleontologists at the Museum of the Rockies in Bozeman, Mont., have developed a new theory for how the T. Rex devoured the best part of his meal: beheading. According to an analysis of bit marks and scarring on the recovered bones of triceratops, T. Rex devised a method of decapitating its fallen prey to expose that succulent neck meat. The best part of all this, of course, are the sketches outlining exactly how this happened (one of which you can see above). Click through to Nature to see, frame by frame, how pencil-sketch-T-Rex made Triceratops into a meal.

Nature

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