Feathered Dinosaur Discovery: Older than Archaeopteryx

- Originally posted October 1, 2009

A new species of "profusely feathered" dinosaur discovered recently in northeastern China is expected to give scientists new insight into the evolution of birds and flight. Significantly, the strata in which  the Anchiornis huxleyi fossils were discovered is between 151 million and 161 million years old, which makes this newly identified species 1 million to 11 million years older than Archaeopteryx, the first known bird species.

The new find, reported at the annual meeting of the Society of Vertebrate Paleontology on September 25, was at first believed to be a primitive bird species. But following examination of the better preserved and more complete remains unearthed in Liaoning, China, researchers are now saying that Anchiornis huxleyi belongs to the dinosaur group called maniraptorans, thought to be closely related to birds. The "four winged" feathered dinosaur is now considered to be the oldest bird-like dinosaur to date, say the researchers.

About two dozen long shafted feathers appear on each forelimb, and a similar number appear on each lower leg and foot, the researchers report.

"This new find suggests that dinosaurs with flight feathers appear at least about 160 [million] years ago and birds' direct ancestors are probably four-winged animals," said study researcher Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences in Beijing.

The species' feathers on the legs and feet appear to have overlapped each other, creating aerodynamic surfaces that essentially would have given Anchiornis a wing on each of its four limbs. A similar arrangement existed in other feathered dinosaurs, including Microraptor (Science News: 1/27/07, p. 53) and Archaeopteryx (Science News: 9/23/06, p. 197).

"Their feathers are very similar to flight feathers of modern birds, but are symmetrical," said Xu. "It is likely that these feathers are used for gliding."