Velociraptor, known from the movie Jurassic Park, had feathers in real life.
A close study of a velociraptor forearm found in Mongolia shows the presence of quill knobs, bumps on the bone where the feathers anchor, researchers report in Friday's edition of the journal Science.
Dinosaurs are believed to be ancestors to modern birds. Evidence of feathered dinosaurs has been found in recent years, and now velociraptor can be added to that list.
"Finding quill knobs on velociraptor ... means that it definitely had feathers. This is something we'd long suspected, but no one had been able to prove," Alan Turner, lead author on the study and a graduate student of paleontology at the American Museum of Natural History and at Columbia University in New York, said in a statement.
The velociraptor the researchers studied was about three feet (0.91 meters) tall and weighed about 30 pounds (13.6 kilograms). The size of these animals was exaggerated in the movie.
It had short forelimbs, compared to a modern bird, the researchers said, indicating it would not have been able to fly, even though it had feathers.
The feathers may have been useful for display, to shield nests, for temperature control or to help it maneuver while running, they said.