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Scientists' find brings 'T. rex' alive

Not literally, of course. But while they probably won't lead to Jurassic parks, the soft tissues could reveal much about how the animals lived.

By wire services
Published March 25, 2005

WASHINGTON - Dinosaurs aren't just piles of dusty bones anymore.

In an announcement that conjured up thoughts of the movie Jurassic Park, researchers revealed they had recovered soft tissues that resemble blood vessels and even cells from a 70-million-year-old Tyrannosaurus rex.

They said they don't know if they will be able to recover DNA - the blueprint to life that was the key to recreating the giant animals in the fictional film.

But scientists say they are excited about the chance to learn more about what went on inside the great beasts, perhaps to learn what they were really made of.

If they can isolate proteins from the material, they could be able to learn new details of how dinosaurs lived, said lead researcher Mary Higby Schweitzer of North Carolina State University. "We're doing a lot of stuff in the lab right now that looks promising," she said. "The bone matrix is flexible. We can hydrate and rehydrate it, and the microstructures are preserved in every way."

Outside scientists said it was unlikely such an ancient sample would yield anything beyond DNA fragments.

"There's no Jurassic Park scenario," said paleontologist Hans-Dieter Sues, associate director of research and collections at the National Museum of Natural History, but he and others said the ability to isolate soft tissues nevertheless could open up research horizons never before imagined.

"Ultimately if we could establish chemical composition, we would have insights into all kinds of things - diet, sexual maturity, whether the specimen is the male or female," Sues said. "There's a lot of biological information locked up in this material."

The soft tissues were recovered from the thighbone of a T. rex, known as MOR 1125, that was unearthed in northeast Montana's celebrated Hell Creek sandstone formation. The dinosaur was about 18 years old when it died.

The bone was broken when it was removed from the site. Schweitzer and her colleagues then analyzed the material inside the bone. The research team systematically removed minerals and fossilized deposits from the thighbone, exposing blood vessels, bone cells and possibly intact blood cells with nuclei.

"The vessels and contents are similar in all respects to blood vessels recovered from ... ostrich bone," they write in a paper published in the journal Science today.

Because evidence has accumulated in recent years that modern birds descended from dinosaurs, Schweitzer said she chose to compare the remains with those of an ostrich, the largest bird available.

Brooks Hanson, a deputy editor of Science, said there are few examples of soft tissues, except for leaves or petrified wood, that are preserved as fossils, just as there are few discoveries of insects in amber or humans and mammoths in peat or ice.

Matthew Carrano, curator of dinosaurs at the Smithsonian's National Museum of Natural History, said the discovery was "pretty exciting stuff."

"You are actually getting into the small-scale biology of the animal, which is something we rarely get the opportunity to look at," said Carrano, who was not part of the research team.

In addition, he said, it is a huge opportunity to learn more about how fossils are made, a process that is not fully understood.

Richard A. Hengst of Purdue University said the finding "opens the door for research into the protein structure of ancient organisms, if nothing else. While we think that nature is conservative in how things are built, this gives scientists an opportunity to observe this at the chemical and cellular level." Hengst was not part of the research team.

John R. Horner of the Museum of the Rockies at Montana State University said the discovery is "a fantastic specimen," but probably is not unique. Other researchers might find similarly preserved soft tissues if they split open the bones in their collections, said Horner, a co-author of the paper.

Most museums, he said, prefer to keep their specimens intact.

Schweitzer said after removing the minerals from the specimen, the remaining tissues were soft and transparent and could be manipulated with instruments.

The bone matrix was stretchy and flexible, she said. Also, there were long structures like blood vessels. What appeared to be individual cells were visible.

She said she did not know if they were blood cells. "They are little round cells," Schweitzer said.

She likened the process to placing a chicken bone in vinegar. The minerals will dissolve, leaving the soft tissues.

The research was funded by North Carolina State University and grants from N. Myhrvold and the National Science Foundation.

Information from the New York Times, Washington Post and the Associated Press was used in this report.

Could the discovery of soft tissues from a Tyrannosaurus rex fossil help lead to the cloning of dinosaurs?

It's highly unlikely, scientists say. No DNA has been recovered from the tissue, and it's unclear if any can be. "There's no Jurassic Park scenario," one paleontologist says.

What's the value of the discovery?

The material could lead to major advances in the study of the animals' actual physiology and perhaps even their cell biology, scientists say.

Why wasn't this discovery made before?

Because dinosaur fossils are rare, scientists are usually unwilling to damage them. The soft tissues were recovered when researchers broke the thighbone of a T. rex as they were moving it from its recovery site in Montana.

What techniques did scientists use to study the tissue?

Just as modern biologists do when doing anatomical studies, researchers put fragments from the broken bone in a mild acid solution to strip away mineral deposits. What was left floating in the solution was thin, stretchy material threaded with what looked like blood vessels.

Compiled from the New York Times, Associated Press and Scripps Howard News Service.

[Last modified March 25, 2005, 01:01:16]