An article published in the journal “The Anatomical Record” reports a study of the anatomy of Tyrannosaurus rex’s skull which offers an explanation of how it could have bite so powerful that it could crush of its prey’s bones without breaking its own bones. A team of researchers led by Ian Cost of Albright College examined the characteristics of the T. Rex skull also using computer simulations concluding that it was as stiff as those of modern hyenas and crocodiles and not as flexible as those of snakes and birds.

The power of the T. Rex bite has already been the subject of research such as, for example, the one published in the journal “Scientific Reports” in May 2017 with the conclusion that this famous dinosaur could crush the bones of its prey. What puzzled the researchers was the fact that the T. Rex bones could withstand such stresses but perhaps a team of researchers coordinated by the University of Missouri solved the mystery.

Ian Cost was a doctoral student at the University of Missouri before becoming an assistant professor at Albright College. He led an anatomical study of the T. Rex skull based on 3D reconstructions and computer simulations that include an engineering analysis to understand how it reacted to the stresses and strains generated during chewing.

The image (Courtesy University of Missouri. All rights reserved) shows a 3D image of the T. rex skull showing muscle activation. The colors tending towards red indicate areas of greatest strain during chewing.

Kaleb Sellers, a student from the University of Missouri who participated in this study, explained that, in the past, researchers only examined the problem from the bone perspective without accounting for all the connections made up of ligaments and cartilages that really mediate the interactions between the bones. There are fossil skulls of T. Rex but the other anatomical parts not available have been reconstructed based on the knowledge of other species, however, this can lead to errors. Paleontologists thought that the T. Rex skull was as flexible as those of snakes and birds but the results of this study indicate that it was as stiff as those of hyenas and crocodiles.

In computer simulations, the researchers used models of the chewing of two distant relatives of T. Rex, the gecko and the parrot. Casey Holliday, associate professor of anatomy at the University of Missouri, explained the problem of the tradeoff between movement and stability of the skull joints. Birds and lizards have more movement but less stability. Such a situation would have created problems for T. Rex and this indicates that its skull had more rigidity.

These biomechanical studies are useful not only to better understand how extinct animals ate and extreme cases such as T. rex but also to improve our medical knowledge. That’s because the developed models can be adapted to existing species that may suffer from joint problems, arthritis and more. It’s a progress that can also help doctors who treat human beings.