Paleontologists Reconstruct Neuroanatomy of Thecodontosaurus antiquus

Wednesday, December 16, 2020

Life restoration of Thecodontosaurus antiquus. Image credit: Mario Lanzas / CC BY-SA 4.0.

A team of paleontologists from the University of Bristol and the Oxford University Museum of Natural History has digitally reconstructed the brain of Thecodontosaurus antiquus, a species of small sauropodomorph dinosaur that lived some 205 million years ago (Late Triassic period), and found that this dinosaur may have eaten meat, was bipedal, and had adaptations to retain a steady head and gaze while moving.

“Our analysis of Thecodontosaurus antiquus’ brain uncovered many fascinating features, some of which were quite surprising,” said lead author Antonio Ballell Mayoral, a Ph.D. student in the School of Earth Sciences at the University of Bristol.

“Whereas its later relatives moved around ponderously on all fours, our findings suggest this species may have walked on two legs and been occasionally carnivorous.”

Using CT scanning, the researchers created detailed 3D models of Thecodontosaurus antiquus’ brain and identified previously unseen anatomical details.

“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,” Ballell Mayoral said.

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

“Its brain cast even showed the detail of the floccular lobes, located at the back of the brain, which are important for balance. Their large size indicate it was bipedal.”

“This structure is also associated with the control of balance and eye and neck movements, suggesting Thecodontosaurus antiquus was relatively agile and could keep a stable gaze while moving fast.”

Braincase and endocast of Thecodontosaurus antiquus. Image credit: Antonio Ballell / /

The scientists were also able to reconstruct the inner ears of Thecodontosaurus antiquus, allowing them estimate how well it could hear compared to other dinosaurs.

The dinosaur’s hearing frequency was relatively high, pointing towards some sort of social complexity — an ability to recognize varied squeaks and honks from different animals.

“Our analysis showed parts of the brain associated with keeping the head stable and eyes and gaze steady during movement were well-developed,” Ballell Mayoral said.

“This could also mean Thecodontosaurus antiquus could occasionally catch prey, although its tooth morphology suggests plants were the main component of its diet. It’s possible it adopted omnivorous habits.”

“It’s great to see how new technologies are allowing us to find out even more about how this little dinosaur lived more than 200 million years ago,” said senior author Professor Mike Benton, a paleontologist in the School of Earth Sciences at the University of Bristol.

The findings were published in the Zoological Journal of the Linnean Society.


Antonio Ballell et al. The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquusZoological Journal of the Linnean Society, published online December 14, 2020; doi: 10.1093/zoolinnean/zlaa157