Watch CBS News

Argonne Laboratory Scan Finds T-Rex's Arms Not Used Much

CHICAGO (CBS) -- The preliminary results are in after scientists at the Field Museum and Argonne National Laboratory teamed up to answer the question: Did Sue, the Field's famous Tyrannosaurus Rex, ever use those tiny arms?

The short answer is, probably not, at least not as an adult.

Sue was disarmed, if you will, last week. One of her arms was temporarily amputated and sent to Argonne for some high-tech testing.

Peter Makovicky, the Field Museum's associate curator of dinosaurs, said the initial results show there wasn't a lot of stress put on the arm.

"This would be consistent with the fact that the arms are rather small and maybe not being used very much by the animal," he said.

So, basically, those short arms were just sort of there.

"Yeah, in some sense. Now, whether this is true throughout the life of the organism, or whether the arms are more actively used at much earlier life stages, that we can't say," Makovicky said.

In other words, Sue - who died when she was about 28; old for a T. Rex - probably didn't get a lot of use out of her arms, at least in her golden years.

"The evidence we're seeing so far is that they weren't being used much. They weren't being subjected to a lot of stress and strain. So they probably were largely vestigial," Makovicky said.

However, that's not the end of it. Makovicky said researchers are still studying the question.

Sue's arm was returned to the museum on Tuesday, and reattached on Wednesday.

"So Sue is complete again," Makovicky said.

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.