- The Washington Times - Friday, March 25, 2005

REUTERS NEWS AGENCY

For more than a century, the study of dinosaurs has been limited to fossilized bones. Now, researchers have recovered 70-million-year-old soft tissue from a Tyrannosaurus rex.

If scientists can isolate proteins from the material, they might be able to learn new details of how dinosaurs lived, said lead researcher Mary Higby Schweitzer of North Carolina State University. But, she said she does not yet know if scientists will be able to isolate dinosaur DNA from the materials.

It was recovered dinosaur DNA that was featured in the fictional re-creation of the ancient animals in the book and film “Jurassic Park.”

“We’re doing a lot of stuff in the lab right now that looks promising,” said Miss Schweitzer, whose study appears in today’s issue of the journal Science.

“If we have tissues that are not fossilized, then we can potentially extract DNA,” says paleontologist Lawrence Witmer of Ohio University in an article accompanying the study. “It’s very exciting.”

The soft tissues were recovered from the thighbone of a T. rex, known as MOR 1125, that was found in Montana’s Hell Creek Formation. The dinosaur was about 18 years old when it died.

The bone was broken when it was removed from the site. When Miss Schweitzer and her colleagues got the bone to a lab and chemically removed the hard minerals, they found what looked like blood vessels, bone cells and perhaps even blood cells.

Miss Schweitzer said the vessels were flexible and in some cases their contents could be squeezed out.

“The microstructures that look like cells are preserved in every way,” she said. “Preservation of this extent, where you still have this flexibility and transparency, has never been seen in a dinosaur before.”

Studying the soft tissues might help answer many questions about dinosaurs. Were they cold-blooded like reptiles, warm-blooded like mammals or somewhere in between? How are they related to living animals?

Miss Schweitzer, a biologist by training, compared the T. rex samples with bone taken from a dead ostrich. She chose an ostrich because birds are thought to be the closest living relatives of dinosaurs.

Both the dinosaur and ostrich blood vessels contained small, reddish brown dots that could be the nuclei of the endothelial cells that line blood vessels.

Taking the minerals out of both ostrich bone and the T. rex bone yielded flexible fibers. Microscopic examination showed what look like bone cells called osteocytes in both.

The finding shows fossilization does not proceed as science had assumed, Miss Schweitzer said. Since the discovery, she has found similar samples of soft tissue in two other T. rex fossils and a hadrosaur.

Paleontologist Jack Horner said he hoped museums around the world would start cracking open bones and looking for soft tissue in their fossils.

“Dinosaurs are relatively rare and we certainly think of T. rex as being really rare — although it really isn’t — so people tend not to want to cut holes into the bone or cut them in half,” he said.

“But to study the cellular and molecular structures of these things you have to do that,” Mr. Horner said. The “good stuff” is on the inside.

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