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Luis Chiappe and CNN.com - Fossil ruffles feather evolut



I didn't get the attachment correctly.  Here's the info:

NEW YORK (AP) -- A 150 million-year-old fossil from southern Germany has
paleontologists ruffled over how feathers arose in the line of dinosaurs
that eventually produced birds.

The fossil is a juvenile carnivorous dinosaur about 2 1/2 feet long that
paleontologists have named Juravenator for the Jura mountains in southern
Germany where it was found.

It would have looked similar in life to the fleet-footed predators that
menaced a young girl on the beach during the opening scene of "The Lost
World," the second "Jurassic Park" movie.

The fossil's exceptionally well-preserved bone structure clearly puts it
among feathered kin on the dinosaur family tree. Because all of its close
relatives are feathered, paleontologists would expect Juravenator to follow
suit.

But a small patch of skin on Juravenator's tail shows no sign of feathers.
And the skin also doesn't have the follicles that are typical of feathered
dinosaurs, said Luis Chiappe, director of the Dinosaur Institute at the
Natural History Museum of Los Angeles County.

He and Ursula B. Gohlich of the University of Munich describe the fossil in
Thursday's issue of the journal Nature.

"It has a typical scaly dinosaurian skin," Chiappe said.

The paleontologists believe Juravenator's closest known relative may have
been a fully feathered dinosaur from China, Sinosauropterix.

There are a number of possible explanations for Juravenator's nakedness.
Feathers could have been lost on the evolutionary line leading to
Juravenator after arising in an ancestor to both it and its feathered
relatives.

Or feathers could have evolved more than once in dinosaurs, cropping up in
sister species at different times and places. It is also possible that this
particular fossil of Juravenator, which appears to be a juvenile, only grew
feathers as an adult or lost its feathers for part of the year.

But there is another possibility as well, said Mark Norell, curator of
paleontology at the American Museum of Natural History: It is entirely
possible that Juravenator did have feathers, but they simply failed to
fossilize.

"Feathers are really just difficult things to preserve," Norell said.

To support his hypothesis he pointed out that several fossils of the oldest
known bird, archaeopteryx, lack feathers.

Whether or not the new specimen raises interesting questions about how
feathers -- and thus birds -- evolved, most experts do not see it as a
challenge to the widely accepted view that modern birds are descended from
dinosaurs.

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