Monday, April 30, 2007

Early history of birds much more diverse than once thought

Roadrunner-like birds skittered around under the feet of dinosaurs 125 million years ago, according to ancient tracks found in fossilized Chinese mud two years ago.

Denver paleontologist Martin Lockley has now officially described the tracks, and experts say the discovery means there were many more types of birds flitting around dinosaurs than once thought. ...

...A decade or so ago, scientists had only a few fossils of marine birds that soared around during the age of the dinosaurs, said paleontologist Luis Chiappe of the Los Angeles County Museum.

"Most of us thought that birds just weren't very diverse in the Mesozoic, the age of the dinosaurs," Chiappe said.

In recent years, paleontologists have found new bird fossils from millions of years ago, some with short beaks, others long, some that ate seed and had insects in their stomachs when they died, Chiappe said.

"This is very interesting," he said of Lockley's new paper. "It adds to a realization that the early history of birds was extremely diverse."