A student at the Virginia Polytechnic Institute, Simba Shrivastava, managed to reconstruct a heavily damaged dinosaur skull discovered more than 40 years ago and described a new species that lived over 200 million years ago. The discovery forces a reconsideration of ideas about early dinosaur evolution and the consequences of the mass extinction at the end of the Triassic period. The work was published in the journal Papers in Palaeontology.

A Find That Lay in Archives for Decades

The fossil was originally discovered in 1982 by an expedition from the Carnegie Museum of Natural History in New Mexico. However, due to its extremely poor state of preservation, the skull remained largely overlooked for many years and was stored in the archives. Several years ago, it was transferred for study, and the project was taken up by student Simba Shrivastava.

Using computed tomography, he separated the fossil into individual fragments, created a digital model, and produced a 3D-printed reconstruction of the skull. This made it possible to study in detail the anatomy of an animal previously unknown to science.

A New Species — the “Folded Hunter with Full Cheeks”

The new dinosaur was named Ptychotherates bucculentus, which roughly translates as “folded hunter with full cheeks.” It lived in the late Triassic period—long before the appearance of tyrannosaurs and other well-known giants of the Cretaceous period.

At that time, dinosaurs had not yet become dominant on land and competed with ancestors of modern crocodiles and early mammals. Ptychotherates bucculentus belonged to an ancient group of predatory dinosaurs known as herrerasaurians (Herrerasauria), which had been considered among the earliest representatives of dinosaurs.

A distinctive feature of the new species is the unusual shape of its skull, with large cheekbones and a relatively short snout. Such anatomy had not previously been observed in early theropods.

The Importance of the Discovery for Evolutionary History

The find may represent one of the last members of the herrerasaurian group. Previously, scientists believed that this group had gone extinct much earlier, before the end of the Triassic. Researchers now suggest that the southwestern region of what is now the United States may have served as the final refuge for these ancient predators.

Simba Shrivastava noted that the small fragment represented the only evidence that such dinosaurs existed for so long and possessed this type of skull structure.

The discovery also prompts a reassessment of the consequences of the mass extinction at the end of the Triassic period. Scientists had previously assumed that this extinction mainly eliminated the competitors of dinosaurs, clearing the way for their dominance. However, the new data indicate that the extinction also affected some groups of dinosaurs themselves.

In Brief

A student at the Virginia Polytechnic Institute, Simba Shrivastava, reconstructed a heavily damaged dinosaur skull discovered in 1982 in New Mexico and described a new species—Ptychotherates bucculentus. This predator lived more than 200 million years ago in the late Triassic period and belonged to the ancient herrerasaurian group. Its unusual skull shape, featuring large cheekbones, makes it unique. The discovery shows that some early dinosaur lineages survived longer than previously thought, and that the southwestern United States may have served as their final refuge. The study was published in Papers in Palaeontology. Even highly fragmented fossils can fundamentally change our understanding of the evolution of ancient ecosystems.