Scientists uncover dinosaur ‘mummies’ with hoofs like a horse

It’s been greater than 60 million years since duck-billed dinosaurs roamed round what’s now referred to as western North America.

Or, extra precisely, since they clomped round. On their hoofs. 

This, based on a brand new research of “dinosaur mummies” — fossils during which the exterior anatomies of dinosaurs are rendered in unbelievable element onto skinny layers of historic clay. 

It marks the primary time hoofs have been discovered on a dinosaur or, actually, any reptile. But the researchers behind the invention anticipate extra will flip up, now that folks know to search for them.

“I think people’s antennae will be up now to try and make sure there’s nothing there when they’re excavating,” University of Chicago paleontologist Paul Sereno, the research’s lead writer, instructed As It Happens host Nil Köksal.

The findings, published in the journal Science, paint essentially the most full image so far of what duck-billed dinosaurs really appeared like.

What’s extra, the research unravels the long-standing thriller of how these so-called dinosaur mummies fashioned within the first place. 

The cows of the Cretaceous Period

Duck-billed dinosaurs have been way more frequent than their extra well-known contemporaries of the Cretaceous Period, just like the apex predator Tyrannosaurus, or horned dinosaur Triceratops.

In reality, these almost three-metre lengthy plant eaters have been a favorite meal of the T. Rex. 

Also referred to as Edmontosaurus — as a result of the primary fossils have been found in southern Alberta  — they roamed collectively in big herds, grazing on crops,  very like modern-day cows, sheep and goats.

Also like in the present day’s grazing mammals, these dinos developed hoofs, buildings that protected their toes, supported their weight, provided traction and absorbed shock from the affect of all that strolling — and operating for his or her lives.

“It’s remarkably like a later equine or horse hoof, or something that you might see on a relative, a tapir or a rhino,” Sereno said. 

“There’s a shield around the outside, and then sort of a soft core on the bottom side that really resembles the mammalian hoofs that evolved so much later.”

It’s an example of a phenomenon known as convergent evolution, in which different organisms independently evolve similar features  — like the wings of birds, bats and the extinct  flying reptiles called pterosaurs — while adapting to similar  environments or ecological niches.

What even is a dinosaur mummy?

Sereno and his colleagues identified the hoofs on a pair of detailed fossils known as dinosaur mummies. They are skeletons that, on first glance, appear to be covered in remarkably well-preserved skin. 

Scientists have been uncovering these types of fossils for more than a century, many of them in the badlands of eastern Wyoming, in an area known as “the mummy zone.” 

Sereno and his colleagues wanted to understand the process that creates these mummies. But the name, it turns out, is a bit of a misnomer.

“People will think of Egyptian mummies and ask what is a dinosaur mummy? That was our question in the first place,” said Sereno.

Mummification usually refers to the preservation of flesh, either intentional or natural. But these mummies, it appears, are flesh-free. 

The study looks at two duck-billed dinosaur fossils excavated in Wyoming in the early 2000s.

Sereno says the specimens don’t actually contain any skin, DNA or tissue. 

It’s just clay.

The two Edmontosaurus died some 66 million years ago, possibly in a drought, and their dried out carcasses were covered in a flash flood that left them coated in a film of clay about 0.025 centimetres thick.

That clay then hardened with the help of microbes. When the skin and flesh decayed, it left behind bones encased in clay masks that preserved the creatures’ shapes, including the contours of their bodies and scaly skin.

 “It’s a beautiful rendering of what the animal looked like,” Sereno said. 

This style of mummification has preserved other organisms before, but scientists didn’t think it could happen on land. It’s possible that other mummies found at the Wyoming site could have formed in a similar way, Sereno said.

Understanding how dinosaur mummies form can help scientists uncover more of them, says Mateusz Wosik, a Misericordia University paleontologist who wasn’t involved with the discovery. It’s important to look not just for dinosaur bones, but also for skin and soft tissue impressions that could go unstudied or even get picked away during the excavation process.

More mummies offer more insights into how these creatures grew and lived, says Stephanie Drumheller, a vertebrate paleontologist at the University of Tennessee,

“Every single time we discover one, there’s such a treasure trove of details about these animals,” said Drumheller, who wasn’t involved in the research.

These renderings, paired with what scientists already know from other fossils, paint a detailed picture of what a duck-billed dinosaur looked like, from its heads to its hoofs.

According to the study, it has a ridge running down its neck and back, which breaks out into a row of spikes running down the tail. Its skin was covered in tiny, pebble-like scales, most no bigger than those of an average lizard. 

And, as we now know, it was hooved. 

“This is a landmark,” Sereno said. “We really know this dinosaur now.”