Fossil discovered in New Mexico may belong to T. rex ancestor

ALBUQUERQUE, N.M. — Scientists identified a fossil from New Mexico as belonging to a dinosaur that may have been an ancestor of the Tyrannosaurus Rex.

The research shows large tyrannosaurs lived in New Mexico millions of years earlier than first realized. It’s believed that this will bring researchers closer to understanding where and how tyrannosaurs evolved.

New Mexico Museum of Natural History and Science Executive Director Dr. Anthony Fiorillo and curator Dr. Spencer Lucas coauthored the research. Scientific Reports published it, offering new insights.

“This New Mexico discovery shifts the timeline for how some of the largest predators of all time evolved and provides new insight on where they came from,” Fiorillo said. “Based on what we now know, it’s possible the ancestors of the most famous dinosaur of all evolved in what’s now New Mexico.”

The fossil was a shin bone found in the Bisti De-Na-Zin wilderness. They initially identified it as Bistahieversor but later matched it more closely with Tyrannosaurus. Radioactive dating places the fossil at 74 to 75 million years old, suggesting a T. rex ancestor may have roamed New Mexico.

The study’s lead author, Dr. Nick Longrich, noted more evidence is needed to confirm this as a T. rex ancestor. However, the current data supports this hypothesis.

“Debate is how science proceeds,” Longrich said. “By throwing this hypothesis out there, it will provoke debate and hopefully encourage people to take a closer look at museum collections and look for new material in the field. New fossils will support this hypothesis or reject it. Either way we’ll walk away with a better understanding of how the dinosaurs evolved.”

The New Mexico Museum of Natural History and Science will reopen April 4.