Ancestor of modern birds found

The fossil of a bird that lived 110 million years ago in China could be the ancestor of all modern birds. From New Scientist:

Gansus yumenensis was a foot-propelled diver like modern loons or grebes and about 25 centimetres long, says Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh, US. Although Gansus was not a direct ancestor of modern birds, it was the closest to modern birds yet found from the early Cretaceous.

The discovery offers new insight into the origins of modern birds, which remain a puzzle because fossils of their ancestors are scarce. Although many fossil birds are known from 125-million-year-old deposits in China's Liaoning province, the most common belonged to a now-extinct group called enantiornithines.