CT scan of Daspletosaurus skulls reveals new details

75 million years ago, during the late Cretaceous period, a large predatory dinosaur, Daspletosaurus, belonging to the tyrannosaur family and predating its most famous "cousin", the Tyrannosaurus Rex, at least 10 million years old. A team of researchers recently used a series of CT scans to examine two particularly well-preserved specimens of Daspletosaurus, managing to reconstruct a digital image of the skull, inner ear and, most importantly, the brain.



The results obtained, later published in the Canadian Journal of Earth Sciences, contrast with the common opinion according to which the brains of dinosaurs and the bones that contained and protected them would have varied little between individuals of the same species or of different but closely related species. According to Dr. Tetsuto Miyashita, paleontologist at the Canadian Museum of Nature, the study conducted on the two specimens of Daspletosaurus would prove exactly the opposite.

Tyrannosaurs are known to have relatively large brains for dinosaurs, and this certainly applies to Daspletosaurus. The basic shape of the brain, inner ear, and skull also suggests that the individuals analyzed were part of two distinct Daspletosaurus races. One of the two subjects comes from the specimen exhibited at the Canadian Museum of Nature in Ottawa. Found in 1921 along the banks of the Red Deer River in Alberta, it was only described as Daspletosaurus Torosus in 1970 by Dr. Dale Russell, thus ushering in the "modern era" of tyrannosaurid research. The second specimen, on the other hand, was discovered in 2001, and is kept at the Royal Tyrrell Museum of Paleontology in Alberta. Dr. Miyashita is currently continuing to study it, together with Dr. Philip Currie of the University of Alberta, another author of the study.

The study of the structure of the skull and its intracranial cavity has provided interesting insights on the animal brain itself, as well as indications regarding characteristics such as the arrangement of the cranial nerves, as well as some aspects of sensory biology, such as auditory and visual anatomy, which governed the life of the dinosaur.

Dr. Ariana Paulina Carabajal, expert in dinosaur skulls and co-author of the same study at the Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET-Universidad Nacional del Comahue), provided the detailed models of the anatomy of the brain, ear internal and related structures. Among the interesting features of these models, we find the presence of large bone canals, having the function of containing thick nerve bundles intended for the movement of the eyeballs. The researchers also describe large air pockets, which occupied most of the bones of the skull. These cavities, present moreover also in other species of theropods, made the skull extremely light, in relation to its size, also helping to amplify the sound and significantly improve the hearing of the animal, allowing it to clearly identify the direction from which a noise.



The study continues, however, given that only a small number of finds have been examined, it is not yet possible to reach any definitive conclusion on the differentiation of these traits, even if, currently , the data tend to confirm the theory. If you would like to know more about paleontology and dinosaurs, we recommend the Rise and Fall of the Dinosaurs. The true story of a lost world, by Steve Brusatte, available for purchase at this Amazon link.