Posted on 03/15/2006 12:23:34 PM PST by The_Victor
LONDON (Reuters) - A newly discovered, perfectly preserved fossil of a 150 million-year-old dinosaur found in southern Germany may force scientists to rethink how and when feathers evolved.
The nearly complete remains of the chicken-size dinosaur named Juravenator, which is described in the journal Nature on Wednesday, were preserved in limestone. But unlike other members of the group of two-legged meat-eating predators known as coelurosaurs, it had no feathers.
"It is an absolutely new dinosaur that was not known before," said Ursula Gohlich, a palaeontologist at the University of Munich in Germany.
Remains of small dinosaurs from the Late Jurassic period are rare finds. The new fossil is nearly complete, apart from a missing part of its long tail, and shows soft tissue and an imprint of the skin but no feathers.
"Scientists had thought that all representatives of the group coelurosaurs should have feathers," Gohlich told Reuters.
"Now we have a little dinosaur that belongs to coelurosaurs that does not show feathers. This is a problem."
COMPLEX EVOLUTION
Feathers were thought to have evolved very early within coelurosaurs. All members of the group were thought to be feathered.
But Gohlich and Luis Chiappe, of the Natural History Museum of Los Angeles County in California, believe the evolution of feathers may be more complex than previously thought.
Feathers may have evolved early but then were replaced by scales in some creatures because they were not needed.
"Another possibility perhaps is that some representatives of coelurosaurs were not entirely covered with feathers, only certain areas," said Gohlich.
The newly discovered Juravenator was very young so may not have lived long enough to develop feathers. But Gohlich said that despite its age, she would have expected it to have had feathers.
"We think that feathers evolved. We have several fossils that support this theory. But our fossil asks some questions," she added.
The oldest known bird, Archaeopteryx, was also found in southern Germany. It too lived about 150 million years ago and had feathers but it is uncertain whether they were used to fly or to keep warm.
Xing Xu, of the Chinese Academy of Sciences in Beijing, said whatever the explanation, the discovery of Juravenator has enriched knowledge of early feather evolution. It could also indicate where future research could be concentrated.
"Juravenator may complicate the picture, but it makes it more complete and realistic," he said in a commentary in the journal.
Part of the beauty of argument by analogy is it's simplicity in expressing the similarities of complex issues, but, as you say, the devil is in the details, and can somtimes make one want to bang one's head with a copy of Logic orCritique of pure reason.
The only similarity you've shown is that both contain complex information within a framework of simplicity. Something that can be said, and expressed, of virtually anything.
At Talk Origins, they describe how embryonic marsupials develop an egg shell which is then resorbed, and how some are born with a caruncle (like an egg tooth).
Makes evolutionary sense.
Weren't pterodactyls furry? I believe they were archosaurs, so they aren't closely related to mammals.
It says a grad student was quoted in a University press release as saying it was a meat eater. If the scientific paper on this find claims that based solely on the footprint, and no other information was relied upon to support a claim that they can tell it definitively was a meat-eater, then I think you have a beef.
But I doubt the actual paper makes that claim; it may say they suspect it was a meat-eater, or that they concluded it it was a meat-eater based on other corroborative evidence.
And a further review of the thread you cited indicates exactly what I suspected, regarding the meat-eating claim, we see that "Junior" already advised you:
Three-toed dinosaurs discovered to date have been carnivores.
Ergo, the conclusion about it being a meat-eater was based on additional information about three-toed dinosaurs, and not just from the footprint of the this single beast. The article may not have included this tidbit, but that's why science isn't done based on lay press accounts written from University press releases.
As I suspected; your comments in that case and mine in this case aren't at all the same. Have a nice day. This conversation is over.
You sure repeat (or originate?) large numbers of false claims for a self-professed truth teller! Like over here for instance where you falsely claimed that non-evolutionists exposed the Archaeoraptor fossil fraud.
In fact that post is full to the brim of wildly counter-factual, yet still arrogant and self righteous, claims. One -- that "Lucy" has "proven to be a chimp" -- was such an embarrassing whopper that you got corrected by a creationist! You realize how rarely that happens?
Maybe because we were made in His image, and blessed with a large amount of intelligence.
I for one, am a very intelligent crappy long distance runner. All my time in the Army still couldn't get me to be good at it.
Just for interest sake only, who or what is the cream?
Feathers first evolved in pillows. It was only later that they were first installed on giant lizards. But they kept falling off so finally they were evolved onto birds.
Dunno. Cockroaches may outlast us, they're pretty sturdy.
The mere mention provides flashbacks of horror and foggy memories of 3am studying frustration. Somebody, somewhere needs to write a better graduate level physics E&M book. Jackson is a good reference but a horrible learning book (the very difficult problems had little relation to the text; almost no examples). I can't believe that someone hasn't stepped up to the plate and replaced or supplemented this text (but then, writing intro grad level physics books is not very lucrative considering the time expenditure per profit ratio. Writing high-level material with that breadth is tough to do - it could take a decade or more, I imagine, to put such a text together.)
Biologists have, on <sarc>rare occasion</sarc>, been known to actually do careful testing and research using real data, too.
But the real research is being done here.
;)
What's next? Are pterosaurs actually elephants with hang gliders?
LOL!
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