Posted on 03/25/2005 5:25:11 AM PST by infocats
Edited on 03/25/2005 5:44:09 AM PST by Sidebar Moderator. [history]
Alive as dinosaurs may seem to children, knowledge of them as living creatures is limited almost entirely to what can be learned from bones that have long since turned to stony fossils. Their soft tissues, when rarely recovered, have lost their original revealing form.
But now a 70-million-year-old Tyrannosaurus rex discovered in Montana has apparently yielded the improbable, scientists reported yesterday: soft tissues, including blood vessels and possibly cells lining them, that "retain some of their original flexibility, elasticity and resilience."
Moreover, an examination with a scanning electron microscope showed the dinosaur's 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.
In a paper being published today in the journal Science, the discovery team said the remarkable preservation of the tissue might open up "avenues for studying dinosaur physiology and perhaps some aspects of their biochemistry." Speaking at a teleconference, the team leader, Dr. Mary H. Schweitzer of North Carolina State University, said, "Tissue preservation of this extent, where you still have this flexibility and transparency, has never been noted in a dinosaur before."
Dr. Schweitzer, as well as 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 largely unaltered. They said the extraction of DNA for studies of dinosaur genetics and for cloning experiments was only a long shot, though at least reasonably possible.
In a separate article in Science, Dr. Lawrence M. Witmer, an Ohio University paleontologist 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 hold out some hope of recovering intact proteins, which are less fragile and more abundant than 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 warmblooded.
"If we can isolate certain proteins, then perhaps we can address the issue of the physiology of dinosaurs," said Dr. Schweitzer, a biologist affiliated with Montana State University as well as North Carolina State.
Excavations of dinosaur remains sometimes turn up preserved tissues other than bone, including feathers, embryonic fragments and internal organs. But as Dr. Schweitzer's group noted, while in these cases their shapes may be preserved, their original composition has not survived "as still soft, pliable tissues."
It is usually difficult to determine what such modified tissues were like in life when fossils are more than a few million years old. The last of the dinosaurs died out 65 million years ago.
The T. rex with the soft tissue was found in 2003 by a fossil-hunting team led by John R. Horner, a paleontologist with the Museum of the Rockies at Montana State . Mr. Horner is a co-author of the journal report, along with Jennifer L. Wittmeyer of North Carolina State and Dr. Jan K. Toporski of the Carnegie Institution of Washington.
The trials of fieldwork led to the discovery of soft tissue inside a thighbone.
Scientists cannot be sure why the tissues survived as they did, though the protection afforded by the bone was almost certainly one factor. Another may have been the possibility that the animal was buried in a virtually oxygen-free environment very soon after death.
Geologically, the T. rex skeleton was excavated from the Hell Creek Formation, in sandstone laid down about 70 million years ago. Geographically, this was deep in a remote corner of the Charles M. Russell National Wildlife Refuge, in Montana. The only way to get the heavy fossils out was by helicopter.
Tyrannosaurs were famously huge predators. This one, estimated to have been 18 years old at death, was not as large as most. Its femur, or thighbone, was three and a half feet long; some T. rex femurs are at least a foot longer. But the creature was large enough so that some of the rock-encased long bones had to be broken in half to fit a helicopter rig - not something paleontologists like to do.
At a laboratory in Bozeman, scientists inspected the broken thighbone before anyone had a chance to apply preserving chemicals, which would have contaminated the specimen. Dr. Schweitzer and colleagues noticed unusual tissue fragments lining the marrow cavity inside the dense bone. Fossilization had not been complete.
When fossilizing mineral deposits in the tissues were dissolved by a weak acid, the scientists were left with stretchy material threaded with what looked like tiny blood vessels. Further examination revealed reddish-brown dots that the scientists said looked like the nuclei of cells lining the blood vessels.
Cloning time!
Related post here: http://www.freerepublic.com/focus/f-news/1369945/posts
Saves on duplicate posts.
Point taken!
You can add your remarks in parenthesis after the title.
Looks like we'll be having some more hot crevo threads... It seems a miracle that this tissue was preserved :-)
Imagine how difficult it must have been for a T-Rex to stick his head in the ground.
And their DNA?
So9
La la la la la la la la la la la la la la la la la la la la la la la la...
Impossible!
Well at least according to those here who say unequivocally that the Earth is only 10,000 years old.
(no offense - really. believe what you want. just don't push it off on my grand kids)
Please do not change the title of an article. For easier reading, please do not use italics for the article. Thank you.
Now they have evidence that the blood vessels of a dinosaur from 70 million years ago is virtually the same as that of an ostrich.
Such similarity is evidence of evolution, because evolution is about how dramatic change occurs over millions of years. And when you find things that stay the same, then you know for sure that things change.
Or something like that.
Uh, you've never seen the pot holes in Chicago's streets have you.
(even 70 million years ago, the Democrats ruled Chicago)
To me I think this calls into question the accuracy of scientific dating methods - carbon-dating, whatever. There's no way tissue like this could last 70,000,000 years. 70,000 millenia? Wow!!! Forgive my skepticism.
Back in the 17th century native Americans had legends and claimed sightings of mammoths according to early explorers, yet no scientific dating methods have dated mammoth remains as even remotely recent. It's possible these claims were erroneous yet not probable given there were at least a dozen of them recorded.
"There's no way tissue like this could last 70,000,000 years."
Evolution takes more faith than Christianity.
OBTW...If an animal that lage is to have tissue to survive he must have died and been buried in quick order. Like in a flood perhaps?
Unfortunately, that will never take place in this day and age. Reporters want to make a difference. Odd, when I was growing up a reporter actually reported and dug until he had answers. Now days most "news" is 10% fact 90% opinion.
Scientists today are similar to judges as far as status in society. They are unquestionable. Their word is final. It reminds me of the Catholic church in the Middle Ages. Back then if you questioned the church you were held up as a heretic and excommunicated or worse. Today if you question the science of this era or their methods you are held up to ridicule.
Maybe they will find the T-Rex was a victim of global warming/cooling (take your pick). But wait if that is the case how can climatic changes 70 million years ago be tied to the Bush anministration?
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