A new species of dinosaur has been discovered… and it grew faster than previously thought | Business Insider Japan

“We realized that traditional guesses about the ages of these fossils were probably wrong.”

After re-examination, it was determined that the bones belonged to Tyrannosaurus rex, which lived 6 to 7 million years before Tyrannosaurus.

In addition, the fossil had several important differences from the typical tyrannosaur, leading Longlich and his team to conclude that it was a new species.

For example, the skull lacked the distinctive bulge behind the eyes, and the lower jaw was shallower than that of Tyrannosaurus, said paleontologist Spencer Lucas, who participated in the study.Talk to NPR.

This research has been summarizedpaperIt was published in the peer-reviewed academic journal Scientific Reports on January 11, 2024.

How did the dinosaur get so big?

Longrich says it's difficult to estimate the size of T. mcraeensis based on its skull and jaw bones alone, but it was likely similar in size to T. rex, and was about 12 meters long (about the size of an American school bus). . there.

This means that the genus Tyrannosaurus “got large much faster than previously thought”, and that the placement of the T. mcraeensis fossil at a specific time in ancient history indicates that the genus TyrannosaurusHugenessThis might explain, Longrich noted

During the Campanian period (83 million to 72 million years ago) in the Late Cretaceous, herbivorous dinosaurs such as hadrosaurs became larger. In order to prey, the tyrannosaurus had to become larger.

like himEvolutionary pressureThis is likely what led to the giant size of the tyrannosaur genus, Longrich says.

He believes that Tyrannosaurus rex was not the first dinosaur, as many scientists have assumed, but it may have been the last.

North America vs Asia

Even famous dinosaurs like the T-Rex have no connection to their origins.Little concept. Scientists are divided on whether T. rex originated in North America or Asia.

However, this new discovery may provide several clues to solve this problem.

T. mcraeensis is the first known fossil ancestor of T. rex, and its discovery in New Mexico supports the theory that T. rex originated in North America rather than Asia, Longrich said.

“It's interesting that even seemingly famous dinosaurs like T. rex are still discovering new things. There is still a lot to discover.”