1st Nearly Intact Skeleton of a Juvenile T. Rex Found

The first nearly complete skeleton of a juvenile Tyrannosaurus rex has been found in South Dakota and is being prepared for study in a Texas laboratory, researchers said Tuesday.

“It really did knock my socks off,” declared paleontologist Robert T. Bakker, who has seen the specimen. “You’re getting a window into the childhood of the world’s favorite dinosaur.”

The skeleton, which Bakker estimated could be 75% to 90% complete, was found north of Belle Fourche, S.D., in the summer of 1998, said Ron Frithiof, an amateur fossil-hunter and a rancher near San Antonio.

The dinosaur, most of it still encased in rock and other material, is now at a lab that Frithiof owns west of San Antonio. He and others have been painstakingly exposing the bones so it can be studied.

Frithiof, a member of the discovery team, said the team was led by a private Houston paleontologist, Mike Harrell, who died recently.

The skeleton was dubbed Tinker, a nickname Frithiof picked up as a kid.

Previously, scientists had never found a complete skeleton “or even a good skeleton” of a juvenile T. rex, although fairly complete skeletons have been found for juveniles of other tyrannosaurs, said tyrannosaur expert Thomas Holtz Jr. of the University of Maryland at College Park.

The finding should help scientists study such things as growth patterns in T. rex, he said.

Bakker, who works with the Wyoming Dinamation Society, based in Boulder, Colo., said the specimen is about 66 million years old. The animal probably weighed about a quarter “as much as Dad,” he said. It might have weighed about 1,200 pounds to 1,500 pounds and measured about 23 feet from the tip of its tail to the snout, he said.

It’s clearly a juvenile because of some unfused backbones, he said. The specimen shows that the juvenile T. rex was “quite gangly, particularly long in the shin and ankle.” That’s “a pleasant confirmation” of prior work, he said.

But “the jaws are 100% adult,” armed with “massive bone-crushing teeth.” That suggests it ate an adult diet, even though it didn’t appear strong enough to wrestle large prey to the ground, he said. So apparently Mom or Dad hunted the meals, and Junior showed up later to munch, he said.