Posted on 06/02/2005 2:06:01 PM PDT by dread78645
WASHINGTON (Reuters) - A Tyrannosaurus rex dinosaur that died 68 million years ago has provided some of the strongest evidence yet that birds are the closest-living relatives of dinosaurs, scientists said on Thursday.
Soft tissue found in the animal's thighbone strongly suggests it was a female, and just about to lay eggs, the researchers report.
The bone tissue is strongly similar to that made inside the bones of female birds -- and no other living type of animal -- when they are producing the hard shells of eggs just before they lay them, said Mary Higby Schweitzer of North Carolina State University in Raleigh.
"In addition to demonstrating gender, it also links the reproductive physiology of dinosaurs to birds very closely. It indicates that dinosaurs produced and shelled their eggs much more like modern birds than like modern crocodiles," Schweitzer told reporters in a telephone briefing.
Female birds produce a layer of bone tissue called medullary bone when they are laying eggs. It is rich in calcium, providing minerals that would otherwise be leached from harder bone material, leaving the bird susceptible to fractures.
"The way that crocodiles lay and shell their eggs is they hold them in their reproductive tract and shell them all at once," Schweitzer said.
"Birds shell their eggs one at a time as they move down through the reproductive tract. It is a pretty calcium-intensive process."
ALREADY A STAR
This particular T. rex fossil made headlines in March when the same team of paleontologists reported it contained preserved soft tissue -- the first ever found in a dinosaur bone.
"The reason that we have found all the things in this one particular animal is this specimen was in a very remote part of Montana, in the Hell Creek formation," said Jack Horner of the Museum of the Rockies and Montana State University.
"It was so far out in the country that we needed to helicopter it out and we actually had to split the thighbone into two pieces to get it into the helicopter."
When Schweitzer unwrapped the cracked-open femur she immediately saw the soft tissue and went to work proving its remarkable state of preservation.
Horner plans to crack open some other bones.
"We have 12 specimens of Tyrannosaurus rex here at this institution, and we are about to find out if any more of them are females, just by looking inside," he said.
It was a stroke of luck to find an animal at just the right stage to be making medullary bone, Schweitzer said.
"It would not be present in a brooding animal," she said.
"But it would be present as long as there was an egg left to lay. The animal was probably near the end of its laying cycle."
Finding another such specimen will be difficult.
"I think it is pretty much a long shot," she said.
In April, Tamaki Sato of the Canadian Museum of Nature in Ottawa, and colleagues reported they had found the fossil of a dinosaur in China that carried two eggs in its body.
Its physiology also was closer to modern birds than to modern crocodiles, Sato reported.
Horner said most experts are convinced the two-legged dinosaurs known as theropods were closely related to living birds.
"This is another piece to the puzzle and there are a lot of them," he said. "Anyone who would argue that birds and dinosaurs are not related -- frankly I'd put them in the Flat Earth Society group."
Excuse me, but isn't it a proven medical fact that men have one fewer rib bones than a woman?
You're kidding, I hope?
Not a failure at all, friend. Let me ask you this: if you were in a car accident and lost a leg, and then had children, would all of your children be born without a leg? Then why does one infer that all men after Adam would have one less rib? Use a little logic...it goes a long, long way.
Not that men really have to have one less rib, no. But think if they did, what a wonderful "confirmation" it would be. I mean, men don't have more and some people claim it anyway.
Ah, VR, I'm glad you are here.
i have a question that will make the creationists yelp for joy, but I think it needs some attention.
The area of human evolution is an area I know only rudimentary things about. There is much empahsis on braincase size on both sides.
1. I take it that it is not only the brain case size (volume) that is used to show lineage, but also what parts of the braincase are increasing?.
2. i ask this because of the common observation like this one: My neighbor on one side has a St. Bernard - really big and really stupid. My neighbor on the other side has a chihuahua, small yappy, but quite "smart". Considering the anatomy of a dog (all the same muscles, bones, etc. for both large and small dosg - is there increased nervous tissue in a large dog?), it seems that a chihuahua's brain would be capable of operating a St. Bernard. What's all that extra brain material doing in the St.Bernard? I think it's sawdust, my neighbor won't let me do an autopsy on that St. Bernard while he's still alive.
I would like to replace my "Warning bad Dog" sign with "Warning bad T-Rex"
Let the Japanese do the cloning.
They will ultra-miniaturize & "bonsai" them (down to, say 100-150 pounds, with bug eyes and a puggish snout) for the pet trade.
Intelligence and brain size only correlate roughly. Dante's brain capacity was on the small size. (OTOH, I'm reading Divina Commedia in English and not finding it all that hot.) While Neanderthals had bigger overall brains than Cro-magnon Man, the regions enlarged were somewhat different. Whales and elephants have big brains, too. They're pretty smart in absolute terms but not particularly in proportion to brain size.
68 million year old "soft tissue"....frankly anyone that believes that I'd put them in the Flat Earth Society group.
Not again!! This theory is never going to fly.
Wouldn't be the claim of most Creationists who know their science. Frankly, the whole idea of 'confirmation' is a bit humorous. What confirmation more does one need than one's faith? Your belief system dictates what you do with the evidence before you--what presuppositions you bring to the table and how you then interpret the same set of evidence. Evolutionists come with their own theory and belief system and it dictates the way they approach science in the same way that Creationists approach science using a different standard.
Day 5.
It's important in science.
Evolutionists come with their own theory and belief system and it dictates the way they approach science in the same way that Creationists approach science using a different standard.
Real science adjusts theories and expectations to fit observation. At times, creationists claim it does not do this, but of course it does. In fact, when it does, creationists cackle and whoop over how "Science has changed its story AGAIN." There's a site IIRC called Creation-Evolution Headlines which does little other than search out every controversy, unexpected result, sour note, or new question uncovered and trumpet it as proof that science is all a house of cards ready to tumble.
Creationism simply throws out all the observations it thinks of as challenging Holy Writ. Thus far, that list includes biology ("Nothing in Biology Makes Sense Except in the Light of Evolution" -- Theodosius Dobzhansky), geology (supports old Earth, no one global flood), paleontology (supports evolution and an old Earth), nuclear chemistry (supports radiometric dating), astronomy (supports an old universe), etc. Oddly enough, most of the people who buy this worldview will also say, "I love science! I just don't believe in evolution."
No; Day Zero.
An unknowable length of time before Day 1, which came after the end of the First Age.
World which was; Second Age, World which is; Third Age, World which shall be. Yet Earth abides.
Capitalized as if it were a title because it is. Also a statement already true in 1973 and far more so now.
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