A new dinosaur species may have been a direct ancestor of the legendary “king of dinosaurs,” the Tyrannosaurus rex, paleontologists said, according to ABC News. 

The newly identified species, called Tyrannosaurus mcraeensis, roamed the Earth 70 to 73 million years ago, predating the T-rex by approximately five million years, according to a study published Thursday, the outlet noted. 

Paleontologists have discovered a new species of dinosaur that could be the closest-known relative of the famed Tyrannosaurus rex. https://t.co/A04EHPN4qW

— ABC News (@ABC) January 11, 2024

Paleontologists first discovered and studied fossils of the new Tyrannosaurus mcraeensis in the 1980s after civilian boaters stumbled upon the dinosaur’s jaw, Spencer Lucas of the New Mexico Museum of Natural History and Science told the outlet.

Researchers at the time assumed the fossils to be those of a Tyrannosaurus rex, and it wasn’t until decades later that paleontologists concluded that the fossils belonged to a previously unknown species, Lucas added, according to the outlet. (RELATED: Engineers Accidentally Discover 125,000,000-Year-Old Dinosaur Fossils)

The two species appear to have had prominent differences in their jaws and postorbital bones, which could be due to their different methods of processing food and attracting mates, Anthony Fiorello, the museum’s executive director, told ABC News. 

The Tyrannosaurus mcraeensis also appears to have lived more than 100 miles inland, while most of the other dinosaur fossils found in Western United States were located within a few miles of the sea coast, Lucas said, according to the outlet. (RELATED: Incredible New Species Of Dinosaur Unearthed)

“We’re looking at a dinosaur fauna that’s living in a rather unique environment” as well as “a whole new species of animal that was not known to science before,” Lucas said, according to ABC.