| By Patricia
Reaney
LONDON (Reuters)
- The discovery of a 130-million-year-old fossil of a feathered dinosaur provides
dramatic evidence that birds evolved from the ancient reptiles, according to new
research published on Wednesday.
Paleontologists at the American Museum
of Natural History in New York, where the fossil on loan from China has gone on
display, believe the skeleton of a young dinosaur covered with primitive fluff
is proof that the creatures developed feathers for warmth not flight and that
dinosaurs evolved from birds.
Dr. Mark Norell, chairman of the division
of paleontology, said in a telephone interview that the fossil was about the size
of a duck with a long tail.
"It shows us that these creatures looked more
like weird birds than giant lizards," he said.
The 2.5 foot long fossil,
described in the journal Nature, was found by farmers in layers of volcanic and
sedimentary rock of the Yixian Formation in China's northeastern Liaoning Province.
It
is a dromaeosaur -- a small, fast-running carnivorous dinosaur with a sickle-like
claw on its middle toe.
The creature is related to the mighty Tyrannosaurus
rex and belongs to a group of dinosaurs called theropods -- two-legged predators
with sharp teeth.
Feathers have been found on dinosaurs which could not
fly and which "pre-dated the origins of birds and avian flight," the article in
Nature said.
Norell said the most reasonable explanation for the feathers
was not for flight but for warmth.
"It's conceivable that smaller dinosaurs
like this one and even the young of larger species like Tyrannosaurus rex may
have needed feathers to keep warm," he said.
MOST COMPLETE FOSSIL OF FEATHERED
DINOSAUR
Until now most of the fossils of feathered dinosaurs, which were
first discovered in 1995, have been incomplete. Scientists opposed to the theory
that birds evolved from dinosaurs argued that the partial remains of the fluffy
prehistoric creatures were not sufficient enough proof for the hypothesis.
They
believe birds evolved independently from a still undiscovered reptile.
Ji
Qiang, of the Chinese Academy of Geological Science which lent the fossil to the
New York museum, said the discovery was particularly important because it showed
the feathers were attached to the dinosaur's body.
"This is the specimen
we've been waiting for. It makes it indisputable that a body covering similar
to feathers was present in non-avian dinosaurs," he said in a statement.
Theropod
dinosaurs and birds share about 100 anatomical features, including a wishbone,
swiveling wrists and three forward-pointing toes.
Norell said dromaeosaurs
were theropod dinosaurs thought to be most closely related to birds. |
