This is an ongoing story and will be updated.
A pristine dinosaur leg uncovered in North Dakota may be a relic from the day a massive asteroid struck Earth, which will end the age of non-avian dinosaurs, scientists claim. However, not all experts are convinced that the dino actually died on that fateful day 66 million years ago.
A team led by Robert DePalma, a PhD student at the University of Manchester, uncovered the fossilized leg with skin still attached. Based on where the leg was found in the fossil site, the team suggested the dinosaur died and was buried during the famous asteroid impact. BBC News reports (opens in new tab). The specimen has not yet been described in a peer-reviewed scientific journal.
The leg is one of them, according to Paul Barrett, a performance researcher at London’s Natural History Museum Thescelosaurusa herbivore dinosaur whose name means “wonderful lizard” in ancient Greek. “It came from a group that we had no prior record of what their skin looked like and it shows very conclusively that these animals were very scaly, like lizards,” Barrett told BBC News. “They were not feathered like their carnivorous contemporaries.”
Based on his examination of the fossil, Barrett said the dinosaur’s leg was likely ripped off very quickly, and the limb shows no signs of disease or was dismembered by scavengers. Barrett examined the fossil on behalf of BBC One, which will soon premiere of a documentary film (opens in new tab) about the location in North Dakota where the specimen was recovered.
BBC One has also brought in Steve Brusatte, a vertebrate paleontologist and evolutionary biologist at the University of Edinburgh in Scotland, as an outside consultant on the project. Brusatte told BBC News he was skeptical of the idea that the Thescelosaurus died the very day the dinosaurs were killed asteroid came hurtling through the sky and punched a huge hole known as Chicxulub Crater in the Yucatán Peninsula.
It’s possible that the Thescelosaurus and other animals discovered at the North Dakota site died days or years earlier, but were violently uncovered during the asteroid impact and then reburied along with debris from the planet-shattering event, Brusatte said.
The North Dakota site known as Tanis has drawn similar skepticism in the past, The science magazine reports (opens in new tab) in 2019.
That year, Robert DePalma, then a graduate student in paleontology at the University of Kansas, and his colleagues reported finding fossilized fish at the site, their gills riddled with small glass spheres called globules. Those freshwater fish included sturgeons and paddlefish, which Science said were found jumbled in a four-foot-thick deposit surrounded by scattered remains of tree trunks and thick mud speckled with more glass beads.
In their 2019 study, the team found these glass spheres to be about 65.8 million years old and theorized that they formed from molten rock blasted into the sky during the Chicxulub impact . They suggested that the fossilized animals at Tanis were originally deposited there by violent seismic waves emanating from the impact site about 3,000 kilometers away, Science reported.
“These fish with the globules in their gills are an absolute calling card for the asteroid,” Brusatte told BBC News. “But for some of the other claims – I would say they have a lot [of] Evidence not yet presented to the jury.”
In addition to the glass-filled fish, the team has reported finding the fossilized remains of a turtle and small mammals; the skin of a triceratops; a pterosaurs embryo enclosed in an egg; and a fragment of what BBC News says may be part of the impact asteroid itself.
“For some of these discoveries, does it even matter if they died in the day or years ago?” said Brusatte. “The pterosaur egg with a pterosaur baby inside is extremely rare; there is nothing comparable from North America. It doesn’t have to be all about the asteroid.”
Originally published on Live Science.