3D Tyrannosaurus rex Skull Model Brings Unexpected Results

Wednesday, October 23, 2019

A 3D image of a Tyrannosaurus rex skull showing muscle activation. University of Missouri scientists created one of the first 3D models showing how ligaments and joints in the skull of a Tyrannosaurus rex work. Courtesy of the MU News Bureau

The T. rex skull has long been considered to be wiggly like that of a bird or snake, but an MU team developed a 3D model that shows that might not have been the case.

One of the great mysteries in the fields of paleontology and anatomy may have been solved by an MU team that created a 3D model for the skull of a tyrannosaurus rex.

These scientists and researchers had long wondered how the dinosaurs were able to shatter bones of their prey without damaging their own skulls. MU scientists are now arguing that the T. rex’s skulls were stiff like those of mammals and crocodiles, rather than flexible like skulls of snakes and birds.

“Previous beliefs about T. rex assumed that T. rex had what we could call a wiggly head. More technically we would call it cranial kinesis,” Kaleb Sellers, a Ph.D. candidate who worked on the model, said.

This assumption was based only on looking at the dinosaur's joints and comparing them to the joints of modern animals with flexible skulls. By creating the 3D model, the team was able to show that it would make much more sense for the skull to be hard.

“Our research showed that anatomically and functionally, the evidence supports a stiff skull for T. rex,” Sellers said.

Casey Holliday, an associate professor of anatomy at the MU School of Medicine, further explained the relationship between the joints and skull to MU News Bureau.

“Dinosaurs are like modern-day birds, crocodiles and lizards in that they inherited particular joints in their skulls from fish — ball and socket joints, much like people’s hip joints — that seem to lend themselves, but not always, to movement like in snakes,” Holliday said to MU News Bureau. “When you put a lot of force on things, there’s a tradeoff between movement and stability.”

This broad principle, when applied specifically to the T. rex, showed why the evidence suggests a stiffer skull.

“Birds and lizards have more movement but less stability,” Holliday said. “When we applied their individual movements to the T. rex skull, we saw it did not like being wiggled in ways that the lizard and bird skulls do, which suggests more stiffness.”

Sellers said this type of 3D modeling can be used not just for the T. rex, but for all dinosaurs and even other animals with fossil records.

“The wider impact of this study on paleontology is that it provides a rigorous way to evaluate the wiggliness, or cranial kinetic status, of fossils,” Sellers said. “T. rex is a sexy example, but it's far from the only interesting animal that paleontologists have an interest in accurately reconstructing.”

Source: www.themaneater.com