As It Happens

Scientists digitally rebuilt the brain of a 205M year-old dinosaur. Here's what they found

Scientists in the U.K. used 3D imaging technology to digitally reconstruct the brain of one of the oldest known dinosaurs to walk the Earth. 

Thecodontosaurus, ancestor of the brontosaurus, was likely bipedal and a little bit carnivorous: study

Thecodontosaurus, depicted here in artwork by J. Dang, lived in what is now Bristol, U.K., 205 million years ago. (De Agostini/Getty Images)

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Scientists in the U.K. used 3D imaging technology to digitally reconstruct the brain of one of the oldest known dinosaurs to walk the Earth. 

They made a number of unexpected findings about the social life and predatory prowess of the Thecodontosaurus, which roamed what is now the United Kingdom more than 205 million years ago.

"I'm very excited about interpreting the way dinosaurs lived, using modern technology," the study's co-author, University of Bristol paleontologist Mike Benton, told As It Happens host Carol Off. 

"When I began in the field, you would poke around with needles and try to get the information in a kind of solid rock form. And in this case, we were able to CT scan the skull of this early dinosaur, and that revealed a lot of the details of the brain."

The findings were published last month in the Zoological Journal of the Linnean Society

What life was like for 'Theco' in balmy Bristol 

The first Thecodontosaurus fossils were discovered in the 1800s, and many have been been well-preserved at the University of Bristol ever since.

But researchers are only now able to really study them in detail without risking destroying them, using 3D models generated from CT scans.

"Even though the actual brain is long gone, the software allows us to recreate brain and inner ear shape via the dimensions of the cavities left behind," lead author Antonio Ballell Mayoral said in a University of Bristol press release. 

"The braincase of Thecodontosaurus is beautifully preserved, so we compared it to other dinosaurs, identifying common features and some that are specific to Thecodontosaurus." 

Lead author Antonio Ballell Mayoral, a PhD student at the University of Bristol's School of Earth Sciences, works on CT scans and takes photos of Thecodontosaurus fossils. (Submitted by Antonio Ballell Mayoral)

The Thecodontosaurus — or "Theco," as Benton calls it for short — was an early relative of the better-known brontosaurus, and dates back to the Triassic period some 205 million years ago.

"Remember, dinosaurs died 66 million years ago. So this is way, way older than those very last ones," Benton said. "They're at the other end of dinosaur history."

Theco was a fairly small dinosaur, about 1.5 metres in length. It's known today as "the Bristol dinosaur" because it made its home in what is now Bristol, U.K. 

But when Theco was on the prowl, North America and Europe were still one continent, and there were no ice caps at the poles. That means that what is now grey and drizzly Bristol would have been a balmy set of tropical islands with weather akin to Florida, Benton said.

"I expect these dinosaurs had great fun hopping around and swimming from island to island."

Not the 4-legged plant eater they were expecting 

Two of the dino's descendents, the brontosaurus and the diplodocus, were four-legged plant-eaters, and scientists had assumed the same was true for Theco — until now.

According to the 3D imaging, Theco had a "fantastically well developed" semi-circular ear canals that help with balance — suggesting it was, in fact, bipedal.

Mike Benton is a professor of vertebrate paleontology at the University of Bristol. (Submitted by Mike Benton)

What's more, it had a large floccular lobes at the back of the brain, which are associated with the control of balance and eye and neck movements, indicating it possessed the "steady gaze" of a predatory bird, like a hawk or an owl.

"If you can get a friendly owl and you just hold the owl gently, of course, and it's looking at something with those great big eyes, as you turn the body, the head keeps riveted as if it's tied to the object it's looking at. So birds have this fantastic ability to fix the gaze," Benton said.

It's what allows a bird of prey to spot a mouse or a vole while swooping over the forest and keep its eyes locked on its prey.

"And so it seems this dinosaur could do the same thing," Benton said. "Therefore, that suggests to us it was still probably a bit predatory."

Benton suspects Theco probably existed during a transition phase where some dinosaurs moved away from all-meat diets. 

"Eventually its descendants, like brontosaurus, of course, they would not feed on meat at all, but this thing probably did," he said. 

What's more, the study's authors concluded Theco was no lone wolf. 

"We were able to calculate the range of hearing, and this suggests that it matched that of a lot of social birds today," Benton said.

"So this suggests to us that these small dinosaurs were hopping around, chirping to each other 200 million years ago."

Written by Sheena Goodyear. Interview with Mike Benton produced by Katie Geleff.

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