China yields a flock of downy dinosaurs.

The Velociraptors of Jurassic Park had a menacing edge to their scaly hides, but Steven Spielberg should have adopted a softer look for his villains. A new fossil discovery in China suggests that Velociraptor and many other types of predatory theropod dinosaurs had coats of downlike fibers.

"This is further support for the idea that birds gradually evolved from theropod dinosaurs," says Xiao-Chun Wu of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing and the University of Calgary in Alberta.

In the Sept. 16 NATURE, Wu and his colleagues describe the newfound dinosaur, which they named Sinornithosaurus millenii. The 124-million-year-old fossil comes from the Yixian rock formation near Sihetun in northeast China, a site fast becoming one of the richest paleontological treasure troves in history.

In 1996, Chinese researchers captured worldwide attention when they unveiled a dinosaur called Sinosauropteryx that showed evidence of fibers adorning its body (SN: 10/26/96, p. 260). Last year, two new dinosaur species turned up at the locality, each of which wore a cloak of birdlike feathers (SN: 6/27/98, p. 404). The parade of fossils continued in the May 27 NATURE, when Xing Xu of the IVPP and his colleagues described Beipiaosaurus, another theropod with a fibrous coat.

With its downlike body covering, the newest fossil resembles Beipiaosaurus and Sinosauropteryx. It belongs, however, to a different family of dinosaurs called dromaeosaurids, which also includes Velociraptor. "Jurassic Park made the dromaeosaurids very famous. Despite that, the anatomical features have been very poorly known," says Wu.

Dromaeosaurids have a special significance because most paleontologists pick this family as the dinosaur group closest to birds. According to the prevailing theory, birds split off from the dromaeosaurid line sometime in the Jurassic period, more than 150 million years ago.

As one of the earliest and most complete dromaeosaurids, Sinornithosaurus helps fill in critical information, says Wu. In particular, the animal had a shoulder socket pointing outward from the body, which would have allowed its arms to move in much the same way as a bird's wings do.

Taken together with the other four recent dinosaur discoveries, the new fossil suggests that fibrous coatings and even true feathers may have covered many different families of dinosaurs, at least at some point in their life cycles, says Lawrence M. Witmer of Ohio University in Athens. These fragile features could only survive, however, when exceptional circumstances preserved them, as happened at the Chinese site.

A small clutch of paleontologists disputes the bird-dinosaur link, arguing that birds arose instead from more primitive reptiles. One of the naysayers, Larry D. Martin of the University of Kansas in Lawrence, contends that the fibers found on the Chinese dinosaurs are the remains of collagen from under the skin, rather than some sort of external coating. He predicts that Chinese excavators will eventually find such fibers on fossils of lizards or perhaps fish, groups that clearly did not have a downy exterior.