Researchers say they’ve recognized a brand new species of Tyrannosaurus that traces the dino’s lineage to North America a lot sooner than beforehand thought, and will shed new gentle on the murky origins of the Tyrannosaurus rex.
T. mcraeensis, the newly named species, is the closest recognized relative of the T. rex, based on a paper just lately published in the scientific journal Nature.
The invention was the results of a research of incomplete cranium and jaw fossils that have been collected in southern New Mexico within the Nineteen Eighties, which now are on show on the New Mexico Museum of Pure Historical past and Science.
“We thought that it was anatomically totally different sufficient that it deserved to be a brand new species,” mentioned paleontologist Spencer Lucas, a co-author of the research and a curator of paleontology on the museum.
The beforehand unknown species had an extended, shallower decrease jaw than its cousin, indicating a much less forceful chew, based on Lucas. The New Mexican fossils additionally lack ridges behind the eyes, a definite characteristic of the T. rex, that the paleontologist says would have allowed the animals to acknowledge members of their very own species.
The newly recognized tyrannosaur is alleged to predate the T. rex by about 6 to 7 million years, and rivals it in dimension at about 40 toes lengthy.
T. mcraeensis provides new inquiries to the continuing debate over the origins of the T. rex. The T. rex appeared in North America way back to 68 million years in the past, its fossils popping up in modern-day Montana and Wyoming. Till now, nonetheless, no shut kin of the species had been acknowledged in North America, based on the paper.
Some paleontologists imagine the Tyrannosaurus migrated to North America from Asia throughout a land bridge. T. mcraeensis — as much as 73 million years outdated — challenges that origin story, says Lucas.
“This fossil suggests one thing totally different could have been occurring — that Tyrannosaurus is in North America hundreds of thousands of years sooner than we knew it was right here,” he mentioned. “Due to this fact, it is fairly attainable that Tyrannosaurus originated in North America. And never simply in North America, however within the Southwest.”
Some within the discipline are skeptical of the paper’s findings. “I hesitate to treat Tyrannosaurus mcraeensis as being distinct from Tyrannosaurus rex,” Jared Voris, who research tyrannosaur biology on the College of Calgary in Canada however wasn’t part of the research, told NewScientist.
Lucas, the co-author, welcomes the counterarguments.
“Hopefully, what’s going to occur now could be, the doubters and perhaps even the supporters will wish to come and research the unique fossil to make their very own evaluation of: How anatomically distinct is it? Do I agree with all of the anatomy reported?” he mentioned.
“That is the best way the science will progress,” he added.