December 1, 2005
Early birds had dino-feet: study
WASHINGTON (Reuters) - An especially well-preserved
specimen of Archaeopteryx shows the first known bird had feet
like a dinosaur -- made not for perching but for running on the
ground, scientists said on Thursday.
The first toe on the fossil turns inward, similar to a
human thumb and most like the hunting dinosaurs known as
deinonychosaurs -- notably the Velociraptor with its long claw
for disemboweling prey.
Gerald Mayr of the Forschungsinstitut Senckenberg in
Frankfurt, Germany, and colleagues at the Wyoming Dinosaur
Center in Thermopolis, say their findings strengthen theories
that birds descended directly from dinosaurs.
The 150 million-year-old fossil, found in Germany's Bavaria
region, suggests the magpie-sized creature could hyperextend
its second toe in a dinosaur-like way, the researchers report
in Friday's issue of the journal Science.
"By all measures, it is a treasure," Peter Dodson of the
University of Pennsylvania was quoted by Science as saying.
The feathered fossils were long believed to be
representative of the first birds and this one now links
Archaeopteryx to dinosaurs.
"Contrary to virtually all existing reconstructions of
Archaeopteryx, the new specimen shows that the first toe was
not fully reversed as in extant birds," the researchers wrote.
"Most workers consider Deinonychosauria to be the sister
taxon of Aves, and the presence of a hyperextendible second toe
in Archaeopteryx supports a close relationship between
deinonychosaurs and avians."