According to the new study, large carnivorous dinosaurs, such as T. rex, evolved eye sockets of different shapes to better cope with high bite force.
Although in many animals, including most dinosaurs, the eye socket is just a circular hole in the skull that houses the eyeball, this is very different in large carnivores.
A new study has revealed how the unusual oval eye sockets found in the skulls of these large carnivorous dinosaurs evolved to help the skull absorb the shock as they pounced on their prey. The study, conducted by scientists at the University of Birmingham, was published in Communication Biology on 11 August 2022.
Dr Stephan Lautenschlager, senior lecturer in paleontology at the University of Birmingham and author of the new study, analyzed the shapes of the eye sockets of around 500 different dinosaurs and related species.
"The results showed that only some dinosaurs had eye sockets that were oval or keyhole-shaped," said Dr. Stephan Lautenschlager. "However, all of these were large carnivorous dinosaurs with skulls 1 meter or more in length."
Dr. Stephan Lautenschlager tested what these unusual eye socket shapes would do through computer simulations and stress analysis.
The results showed that skulls with rounded eye sockets were more susceptible to high stress when bitten. However, if you replace these eye sockets with other eye socket shapes, the pressure will be greatly reduced. This allowed top predators, including T. rex, to evolve high bite force without affecting skull stability.
The study also showed that most herbivorous species and juvenile individuals retain round eye sockets. Only large carnivores take other forms, such as oval, keyhole-shaped, or figure-of-eight eye sockets.
Dr Stephan Lautenschlager added: "In these species, in fact only the upper part of the eye socket is occupied by the eyeball. This also results in a relative reduction in eye size compared to skull size. "
The researchers also investigated what would happen if the size of the eye grew at the same rate as the length of the skull. In this case, the eye diameter of the Tyrannosaurus rex would reach 30 centimeters and the weight would be close to 20 kilograms. Instead of estimated 13 cm and 2 kg.