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Science Scientists recover T rex soft tissue 70-million-year-old fossil yields preserved blood vessels Image: Tissues of a Tyrannosaurus rex. Science via AP Tissue fragments from a Tyrannosaurus rex femur are shown at left, when i t is flexible and resilient and when stretched (arrow) returns to its or iginal shape. The photo at right shows regions of bone showing fibrous character, not nor mally seen in fossil bone.
Updated: 2:05 pm ET March 24, 2005 WASHINGTON - A 70-million-year-old Tyrannosaurus rex fossil dug out of a hunk of sandstone has yielded soft tissue, including blood vessels and p erhaps even whole cells, US researchers reported on Thursday.
Paleontologists forced to break the creature's massive thighbone to get i t on a helicopter found not a solid piece of fossilized bone, but instea d something looking a bit less like a rock. When they got it into a lab and chemically removed the hard minerals, the y found what looked like blood vessels, bone cells and perhaps even bloo d cells. "They are transparent, they are flexible," said Mary Higby Schweitzer of North Carolina State University and Montana State University, who conduc ted the study. She 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," ad ded Schweitzer, whose findings were published in the journal Science. "Preservation of this extent, where you still have this flexibility and t ransparency, has never been seen in a dinosaur before." Feathers, hair a nd fossilized egg contents yes, but not truly soft tissue. Studying the soft tissues may help answer many questions about dinosaurs. Were they cold-blooded like reptiles, warm-blooded like mammals, or som ewhere in-between? "If we can isolate certain proteins, then perhaps we can address the issu e of the physiology of the dinosaur," Schweitzer said. Of course, the big question is whether it will be possible to see dinosau r DNA. We are doing a lot in the lab now that looks promising," Schweitzer said.
Launch To make sure she was seeing what she thought she was seeing, Schweitzer, a biologist by training, compared the Tyrannosaur samples with bone take n from a dead ostrich. She chose an ostrich because birds are thought to be the closest living relatives of dinosaurs and ostriches are big bird s Both the dinosaur and ostrich blood vessels contained small, reddish brow n dots that could be the nuclei of the endothelial cells that line blood vessels. Taking the minerals out of both ostrich bone and the Tyrannosaur bone a simple experiment that can be duplicated by anyone using a chicken bone , for example, and vinegar yielded flexible fibers. Microscopic examin ation showed what look like bone cells called osteocytes in both.
Watch a dinosaur be dismantled The finding certainly shows fossilization does not proceed as science had assumed, Schweitzer said. Since the discovery, she has found similar sa mples of soft tissue in two other Tyrannosaur fossils and a hadrosaur. The fossil was dug up out of Montana's Hell Creek Formation, a rich sourc e of fossils. Paleontologist Jack Horner said it was encased in 1,000 cubic yards (metr es) of sandstone. "The specimen was very far away from road, (so) everything had to be done with a helicopter." The field team used standard procedure as they exca vated the bones, wrapping them in plaster jackets before transporting th em.. This particular dinosaur fossil was too big to lift and they reluctantly cracked a thighbone. Usually paleontologists put preservatives on fossils right away, but Schw eitzer has been trying to find soft tissue in dinosaur fossils, so this one was left alone. Horner said he hoped museums around the world would start cracking open b ones and looking for soft tissue in their fossils. "Dinosaurs are relatively rare and we certainly think of Tyrannosaurus re x as being really rare although it really isn't so people tend not t o 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 h ave to do that." Republication or red istribution of Reuters content is expressly prohibited without the prior written consent of Reuters.
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