Young T. rex or a brand new dinosaur? New bones add to the controversy

Scientists have lengthy puzzled over the origins of a mysterious dinosaur excavated within the Forties: Was it a younger T. rex or one other sort of dinosaur?

At first, researchers had solely a tyrannosaur cranium to go by, making it laborious to inform if it belonged to a toddler or grownup. Another cranium and skeleton nicknamed Jane added to the controversy, however did not settle the controversy.

Now a analysis group mentioned there’s new proof that resolves the case. The newest clue comes from a whole skeleton—first uncovered in 2006 in Montana—that scientists say identifies the thriller reptile as its personal species and never a juvenile Tyrannosaurus rex.

The discovery “rewrites decades of research on Earth’s most famous predator,” mentioned examine co-author Lindsay Zanno with the North Carolina Museum of Natural Sciences and North Carolina State University.

Growth rings throughout the bones present in Montana’s Hell Creek Formation advised scientists the brand new dinosaur was an grownup about half the scale of a fully-fledged T. rex. From progress comparisons to different reptiles like crocodiles, additionally they discovered that the main variations between the creature’s cranium and an grownup T. rex’s—adjustments in bone construction, nerve patterns and sinuses—have been unlikely to kind from merely going via puberty.

Signs pointed to a dinosaur that is a distant T. rex cousin often called Nanotyrannus lancensis, the researchers reported in a examine published Thursday within the journal Nature.

There’s now “more support and evidence than there ever has been” that this T. rex relative might exist, mentioned Holly Woodward, a fossil bone knowledgeable from Oklahoma State University who had no function within the new examine. But she’s not but satisfied that the opposite thriller skeletons like Jane are one thing new.

Other impartial scientists additionally mentioned the controversy is not over. The new skeleton is certainly an grownup, nevertheless it may very well be a sister species to T. rex and never a distant relative, mentioned vertebrate paleontologist Thomas Carr of Carthage College.

There are similarities between the form of T. rex’s cranium and the thriller specimens that maintain him from switching camps.

“I don’t think this study settles everything,” he mentioned.

Resolving this case of mistaken id is vital to understanding how T. rex grew up, mentioned examine co-author James Napoli with Stony Brook University. Another massive query is whether or not T. rex was the primary predator prowling towards the top of the age of dinosaurs 67 million years in the past—or whether or not a tinier, however nonetheless mighty predator additionally roamed.

The new skeleton is dubbed “Dueling Dinosaurs” as a result of it was discovered intertwined with the bones of a Triceratops, and is at the moment on show on the North Carolina Museum of Natural Sciences.

© 2025 The Associated Press. All rights reserved. This materials will not be printed, broadcast, rewritten or redistributed with out permission.