New dinosaur discovery may end long debate over young T. rex origins, know why

For over seventy years, researchers have contested the identity of a mysterious dinosaur unearthed in the 1940s. The main question: was it a juvenile Tyrannosaurus rex or a completely different species?

Primarily, scientists had only a partial tyrannosaur skull, making it challenging to identify whether it belonged to a young dinosaur or an adult one. Later, a fossilized skull and skeleton called Jane reignited the discussion but failed to offer a conclusion to the question.

New Evidence From Montana’s Hell Creek Formation

Currently, scientists believe they finally got the answer. A nearly complete skeleton found in 2006 in Montana has disclosed fresh evidence that, as per the researchers, proves the specimen is a different species, not a juvenile T. rex.

The breakthrough, published Thursday in Nature, “rewrites decades of research on Earth's most famous predator,” stated study co-author Lindsay Zanno of the North Carolina Museum of Natural Sciences and North Carolina State University.

Growth Rings Reveal a Fully Grown Dinosaur

Examination of bone growth rings from the Hell Creek Formation featured that the dinosaur was a fully mature adult approximately half the size of a typical T. rex. Comparisons with reptiles like crocodiles suggested that major differences in skull shape, nerves, and sinus type couldn’t have resulted just from adolescence.

A Smaller Relative Emerges — Nanotyrannus lancensis

This evidence indicates a distant cousin of the T. rex called Nanotyrannus lancensis. The species, long dismissed as a juvenile T. rex, now seems to stand on its own evolutionary tree.

Holly Woodward, a fossil bone specialist at Oklahoma State University not involved in the research, cited there’s currently “more support and evidence than there ever has been” for the species’ existence. Still, she remains cautious, indicating other fossils like Jane might not necessarily showcase a new dinosaur.

Experts Still Split on the Findings

Some paleontologists continue to be unconvinced. Thomas Carr of Carthage College stated that while the recent skeleton is definitely an adult, it may represent a sister species rather than a distant relative of T. rex.
“There are similarities between the shape of T. rex's skull and the mystery specimens that keep him from switching camps,” he said, adding, “I don't think this study settles everything.”

Understanding T. rex’s Evolutionary Growth

Study co-author James Napoli of Stony Brook University described that resolving this identity challenge is significant to understanding how T. rex evolved through its life phase. Another important question is whether the T. rex truly dominated as the apex predator 67 million years ago, or if a smaller but equally fierce hunter shared its range.

“Dueling Dinosaurs” on Display

The newly examined skeleton, called “Dueling Dinosaurs” because it was discovered intertwined with Triceratops remains, is currently displayed at the North Carolina Museum of Natural Sciences, providing visitors a rare glimpse into this prehistoric mystery.

FAQs:

Q1. What did scientists recently find about T. rex fossils?
They found proof that some fossils once believed to be young T. rexes actually belong to a separate species.

Q2. Where was the new dinosaur skeleton discovered?
The fossil was excavated in Montana’s Hell Creek Formation. This region is popular for preserving remains from the late Cretaceous period.