Bird’s oldest ancestors discovered in China

U.S. and Chinese geologists unearthed several nearly complete three-dimensional fossil impressions of uncrushed, loon-like (waterfowl) birds, in Gansu province 2,000km west of Beijing; inheriting the name from that province, the researchers named them ‘Gansus yumenensis.’

The five fossils found in rocks that used to be the muddy bottom of an old lake strengthen the emerging scientific view that early birds evolved in aquatic environments.

The remains of waterfowl - the most ancient known fossils of anatomically modern birds - in a superb state of preservation, are complete with feathers and webbed feet, only the fossils' heads and upper necks are missing. The remains show their structure in rich detail, leading one of the researchers to say that the birds' features are remarkably modern for 110-million years of age.

The skeletons of the ancient birds, which lived 55m years before dinosaurs became vanished, suggest that they dived for their food like modern grebes or ducks. The species, described in today's issue of the journal Science, has been given the Latin name ‘Gansus yumenensis.’

Speaking at a Washington news briefing held by the journal Science, in which the study appears, Jerald Harris of Dixie State College in Utah, said, “No other fossil bird of this age, and even some fossil birds that are much younger than Gansus, has this same suite of modern style features,” adding that “Gansus is, therefore, the oldest known bird that is this modern in its anatomy,” and “It helps us fill a gap in the evolutionary progression towards modern birds.”

“Gansus is very close to a modern bird and helps fill in the big gap between clearly non-modern birds and the explosion of early birds that marked the Cretaceous period, the final era of the dinosaur age," said Peter Dodson of the University of Pennsylvania, who associated with Chinese and American colleagues to examine the fossils.

Gansus is the maiden known instance of the lineage known as ornithurans, which includes modern birds. They substituted for the enantiornitheans - the original proto-birds such as the famous Archaeopteryx and other "feathered dinosaurs". Ornithurans most likely originated as waterfowl and then developed to live on earth.