Friday, March 25, 2005

The New York Times > Science > Tissue Find Offers New Look Into Dinosaurs' Lives

The New York Times > Science > Tissue Find Offers New Look Into Dinosaurs' Lives:

"A 70-million-year-old Tyrannosaurus rex recently discovered in Montana, scientists reported today, has apparently yielded the improbable: soft tissues, including blood vessels and possibly cells, that 'retain some of their original flexibility, elasticity and resilience.'

In a paper being published on Friday in the journal Science, the discovery team said that the remarkable preservation of the tissue might open up 'avenues for studying dinosaur physiology and perhaps some aspects of their biochemistry.'

'Tissue preservation to this extent has not been noted before in dinosaurs,' the team leader, Dr. Mary H. Schweitzer of North Carolina State University, said in a teleconference on Tuesday.

The scientists said that an examination with a scanning electron microscope showed the dinosaur blood vessels to be 'virtually indistinguishable' from those recovered from ostrich bones. The ostrich is today's largest bird, and many paleontologists think birds are living descendants of some dinosaurs.

Dr. Schweitzer and other scientists not connected with the research cautioned that further analysis of the specimens was required before they could be sure the tissues had indeed survived unaltered. They said the extraction of DNA for studies of dinosaur genetics and cloning experiments was only a long shot.

But in a separate article in Science, Dr. Lawrence Witmer, a paleontologist at Ohio University, who had no part in the research, said: 'If we have tissues that are not fossilized, then we can potentially extract DNA. It's very exciting.'

If the tissues are as well preserved as they seem, the scientists held out some hope of recovering intact proteins, which are less fragile and more abundant DNA. Proteins might provide clues to the evolutionary relationship of dinosaurs to other animals and possibly help solve the puzzle of dinosaur physiology: whether, as argued, dinosaurs were unlike other reptiles in being warm-blooded.

"If we can isolate certain proteins, we can address the issue of the physiology of dinosaurs," Dr. Schweitzer said.

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