Researchers Investigate Baby Tyrannosaur Fossil

For now, there are just a few things researchers and students at the University of Kansas want people to dig about the new baby Tyrannosaur fossil they recently excavated in Montana’s Hell Creek Formation.

First off, it’s a “fabulous” complete section of the upper jaw with all of its teeth intact, along with bits of the specimen’s skull, foot, hips and backbones. It’s likely to be the rare fossilized remains of a young Tyrannosaurus rex, which lived 66.5 million years ago.

But it also could be another species of smaller meat-eating dinosaur (it’s a bit of a scientific controversy) — they’re still analyzing their discovery. Careful microscopic preparation of its fragile bones is beginning to reveal important information that will help unravel the life history of Tyrannosaurus rex.

Back at the lab, the researchers found the fossil glowed under a black light. Credit: Meg Kumin, KU Marketing Communications.
Back at the lab, the researchers found the fossil glowed under a black light. (Image: Meg Kumin, KU Marketing Communications.)

Other young tyrannosaur specimens have been recovered over the years, but since animal skeletons change shape as they grow, some confusion as to their evolutionary relationships has ensued. Some paleontologists think the young ones may represent different species, while other workers have suggested they all represent different growth stages of one species — Tyrannosaurus rex.

Excavating the first bone of the baby Tyrannosaur fossil.
Excavating the first bone. (Image: David Burnham.)

KU’s new specimen has the information that may provide the deciding factor of which theory is correct. Researchers believe the specimen is a young Tyrannosaurus rex, but are still conducting their analysis to be sure. They expect to publish their findings in the coming months.

Baby Tyrannosaur fossil may be a different dinosaur

One possibility is the specimen represents another carnivorous dinosaur dubbed a Nanotyrannus, which likewise was discovered in the Hell Creek Formation and described by other scientists.

The KU excavation crew at work. Credit: David Burnham.
The KU excavation crew at work. (Image: David Burnham.)

The Nanotyrannus is a subject of controversy because it may represent a separate species, or it may be a juvenile Tyrannosaurus rex.

For now, Burnham and his team are analyzing the bones they have back in the lab and planning a return to Hell Creek to conduct fieldwork and search for more of the fossil.

Kyle Atkins-Weltman, KU graduate assistant, digs at the Hell Creek Formation site. Credit: David Burnham.
Kyle Atkins-Weltman, KU graduate assistant, digs at the Hell Creek Formation site. (Image: David Burnham.)
In the meantime, Burnham and his fellow researchers (including Kyle Atkins-Weltman, graduate student and assistant fossil preparator) are working on a paper that will address the question of their fossil’s place in the family tree of theropod dinosaurs.
Provided by: University of Kansas  [Note: Materials may be edited for content and length.]

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