Scientists have unearthed two feathered creatures they are calling "unambiguous evidence" that birds are the direct descendants of dinosaurs, and that many meat-eating dinosaurs--perhaps even Tyrannosaurus rex--may have sported tufts of feathers or coats of down.
Preserved in volcanic ash on an ancient lake bed in northeastern China, these 120-million-year-old fossils of two small carnivorous dinosaurs had beaks lined with teeth serrated like tiny steak knives and tails tipped with plumes. The remains clearly show that feathers were common long before birds appeared on Earth or the beginning of bird-like flight.
"These are animals with true feathers, and they are not birds, and they did not fly," said Kevin Padian, a professor of integrative biology and curator of the Museum of Paleontology at UC Berkeley. "This tells us that feathers did not evolve [first] for flight."
The new specimens, excavated by the National Geologic Museum of China over the past year, were unveiled Tuesday at the National Geographic Society in Washington and are documented in detail for the first time in research published this week in the journal Nature.
The two creatures--named Protoarchaeopteryx robusta and Caudipteryx zoui--belong to a branch of the dinosaur clan called theropods that includes a number of fearsome predators like the agile Velociraptors of "Jurassic Park" fame.
Feathered Ferocity
Based on their close kinship and the likelihood of shared family traits among theropods, the fossils raise the possibility that many carnivorous dinosaurs--once depicted as drab, leathery creatures--may have had feathers.
Indeed, as more well-preserved specimens are unearthed, researchers may discover that feathers, so long considered the distinguishing hallmark of birds, may simply be a legacy of their dinosaur heritage--a surviving trace of what was a relatively common characteristic of the denizens that dominated Earth for so many millions of years.
"We would predict on the basis of this evidence that many meat-eating theropods had proto-feathers, which is pretty dramatically different from our traditional view of dinosaurs," said Mark Norell, chairman of the department of vertebrate paleontology at the American Museum of Natural History in New York.
Even the fearsome Tyrannosaurus rex--one of the largest carnivores to stalk the planet and, the growing evidence suggests, a close relative of modern birds--may have had its own garish, downy plumes, several experts speculated.
