The little feathered dinosaur fossil

Jeff Poling

Chinese paleontologists have found the remains of a 121 million year-old feathered dinosaur, providing what could be the most graphic evidence yet that birds are living representatives of the extinct animals. The fossil shows traces of feathery down along its spine and sides. Non-avian dinosaur fossils have heretofore included some remnants of skin, scales and even color patterns, but until now none have shown evidence of feathers.

News of the dinosaur's discovery spread quickly at the 1996 annual meeting of the Society of Vertebrate Paleontology at the American Museum of Natural History in New York, October x through y.

Scientists crowded around to look at photographs of the Chinese specimen brought to the meeting by Dr. Philip J. Currie, chief of dinosaur research at the Tyrell Museum of Paleontology in Drumheller, Alberta, Canada. If the feathered dinosaur is confirmed, say paleontologists who have seen the fossil, then it provides almost irrefutable evidence that today's birds evolved from dinosaurs.

Non-avian dinosaurs did not fly, but a finding that some had feathers would not be altogether surprising. It has long been supposed that feathers might have originated for purposes of insulation, not flight.

"This is not a bird, but it does have feathers,'' said Luis Chiappe of the American Museum of Natural History in New York City. "So the people who resist the dinosaur origin of birds will have a hard time explaining this.''

The finding was announced without an article giving a scholarly assessment of the fossil's origin and date, just a photograph shown by Currie and a Chinese colleague, Dr. Chen Peiji of either the Nanjing Paleontology Institute or Beijing Geology University, articles weren't clear which. Rarely are scientific findings of this possible importance presented so casually.

Dr. Currie said the fossil of the yard-long dinosaur was discovered by farmers near the village of Yianxin in Liaoning Province last August. Paleontologists have become quite familiar with the rocks there, because in the last few years they have yielded spectacular fossils of ancient birds, most of which have had dinosaur-like characteristics.

The age of this and other fossils from Yianxin are controversial as a debate is raging over the age of the deposits there. Chinese scientists estimate that the rocks are about 135 million years old, but recent studies by Canadian geophysicists suggest that the fossil deposits are closer to 121 million years old.

The fossil came to the attention of Currie and a Canadian dinosaur artist, Michael Skrepnick, while in Beijing leading a commercial tour. "The tourists had already left for home, and we were taking some time to look at specimens at the department of geology at Beijing University," Currie said. "When I saw this slab of silt stone mixed with volcanic ash in which the creature is embedded, I was bowled over."

The fossil slab is actually in two parts representing opposite sides of the fossil. Each side was sold by the finder to a different Chinese institution, one in Beijing and the other in Nanjing. The two slabs are complementary; a comparison of photographs of the two sides shows that in places where the line of down along the spine is missing in one slab, it is present in the other.

The scientists describe the down as typical of the kind that in true birds eventually develops into feathers, including the kind used for flight. "The down in this specimen appears to be purely for insulation," Currie said. "There's no sign of the aerodynamic shapes you see in flight feathers."

The photographs, which the Chinese authorities have barred from publication, show a dark, furry ridge running along the animal's spine from the top of its head to the tip of its tail. There is a suggestion of similar downy fur extending part of the way down its sides. It has sharp teeth, long hind limbs, and seems well suited to hunting small prey.

"It's fantastic,'' said Currie. "It's almost mane-like at the back of the head.''

In life, Currie said, the feathered dinosaur was about three feet long. It ran on its hind legs, holding its front limbs in front of it in the manner of the vicious "velociraptors" from the film Jurassic Park.

The dinosaur wasn't a "velociraptor", however. Currie judged from its appearance that the feathered dinosaur is closely related to Compsognathus, a relatively small dinosaur that may have fed on insects and other small animals.

There are only two reasons for any animal to have feathers, Luis Chiappe said. They could be used for flying, which the feathered dinosaur obviously wasn't doing, or they could be using for staying warm.

Because the feathered dinosaur would have used its downy covering to hold in heat, it might be tempting to use the feathered dinosaur as evidence that dinosaurs were warm-blooded. But of all the dinosaurs, Chiappe said, the line that led to birds is among the least likely to have been warm-blooded.

He speculates that the feathered dinosaur may have developed feathers because it was on the road to warm-bloodedness, but hadn't gotten far.

In order to demonstrate conclusively that the impressions represent feathers, rather than feather-like scales or hair-like structures, the Chinese researchers will have to examine the fossil further. But paleontologists said the fossil will be a significant find no matter what the impressions turn out to be.