New Species of Tyrannosaurus Discovered in New Mexico

Tyrannosaurus mcraeensis, an Older and More Primitive Relative of T. rex, Sparks Debate Among Paleontologists

A new species of Tyrannosaurus, named Tyrannosaurus mcraeensis, has been identified by scientists from a partial skull first unearthed in 1983 in southeastern New Mexico.
The newly discovered species is believed to be an older and more primitive relative of the well-known T. rex, predating it by several million years.
The differences between T. rex and T. mcraeensis are subtle, but consistent, including a more slender and curved lower jaw and less prominent brow ridges in T. mcraeensis.
The discovery suggests that Tyrannosaurus originated and evolved in what is now the southern United States, contradicting previous theories that it originated in Asia.
The identification of T. mcraeensis has sparked debate among paleontologists, with some expressing doubt that it represents a new Tyrannosaurus species.