Birds' Oldest Ancestor Found in China
Friday, June 16, 2006
Paleontologists have unearthed the exquisitely preserved fossils of what is the oldest known ancestor of modern birds, a loonlike swimmer and flier that flourished in lake country 110 million years ago in what is today northwest China.
The fossils included five headless but otherwise nearly complete skeletons that show the outlines of soft tissues, including feathers and ducklike webbing between the toes. Researchers said the find suggested modern birds may have evolved from aquatic ancestors.
An international team led by Hai-lu You, of the Chinese Academy of Geological Sciences, found the fossils, known as Gansus yumenensis , in Gansu province near Changma, a mountain community about 1,200 miles west of Beijing. Results of their research are reported today in the journal Science.
"They were clearly able to fly but were also adaptable for swimming and diving," said team member Matthew C. Lamanna, of the Carnegie Museum of Natural History. "We don't know what they ate because we don't have a skull, but the legs and feet are those of a diver. He had a powerful kick stroke."
Lamanna said scientists had unearthed fragmentary remains of gansus, but the latest find provided many new details even as it pushed back the lineage of modern birds an additional 10 million years.
Lamanna described Changma today as a high mountain basin with a harsh climate, but in gansus's time it was pleasant, swampy lake country, rich in plant and animal life.
"Birds are most common, but there are also fish, turtles, fossil insects and lots of plants, and we found one salamander," Lamanna said in an interview. "The age is potentially right to have some of the earliest flowering plants and pollinating insects."
Paleontologists generally regard Europe's archaeopteryx as the world's earliest-known bird. It was magpie-size creature that lived about 150 million years ago and had broad wings and a long, wide tail.
Archaeopteryx showed many reptile characteristics, but its defining trait for years was that it also had feathers. Relatively recent discoveries in northeast China's Liaoning province, however, have turned up several fossils of feathered dinosaurs, forcing paleontologists to redefine where dinosaurs end and birds begin.
"There are no truly flying avian dinosaurs," Lamanna said. "They are all animals with feathers, forelimbs and hind limbs," which could climb, leap and perhaps soar but could not fly. "It's even debatable about archaeopteryx," he said.
Gansus, by contrast, is an obvious bird -- an ancestor of modern birds, Lamanna said, even though it did not have hollow bones, as modern birds do, and still had tiny claws on the ends of its wings.