A previously unidentified species of tyrannosaurus was found in the early 1980s, but not all researchers agree that it is a new species. An American research team has concluded that a partial tyrannosaurus skull discovered more than 40 years ago actually belongs to a species that was previously unknown. This conclusion was reported by the news agency Reuters and other publications.
Originally, the skull was believed to belong to the world’s most famous dinosaur, the Tyrannosaurus rex. However, upon re-examination of the skull compared to other tyrannosaur skulls, researchers concluded that it was a different species, which they named Tyrannosaurus mcraeensis.
The newly discovered species, Tyrannosaurus mcraeensis, is believed to have lived several million years before the Tyrannosaurus rex and to have been slightly smaller, at less than 12 meters long. Researchers studied the lower jaw and head of the mcraeensis to find differences from that of a rex, and reclassified it as a new species.
Some researchers have not accepted the estimates that it is a new species. Thomas Carr, a paleontologist at Carthage University in Wisconsin, says the research has not convinced him and that he has seen mcraeensis several times and nothing stands out as being in any way different from other adult T. rexes.
The new discovery of Tyrannosaurus mcraeensis changes the understanding of the origin of tyrannosaurs. Unlike previous beliefs that large tyrannosaurs evolved millions of years earlier, researchers now think that large tyrannosaurs originated in southern North America. This challenges the notion that tyrannosaurs evolved from a group that crossed a land bridge to North America from what is now Asia.