Five beautifully preserved headless fossil skeletons discovered in China suggest modern birds evolved from aquatic duck-like ancestors. The creatures, which shared the planet with dinosaurs 110m years ago, are the oldest modern bird fossils ever found. The finds were made by US and Chinese researchers in the north-western Gansu province . The species, named Gansus yumenensis after the region and the nearby city of Yumen, was previously known only from a fossil leg found in 1983. Hai-Lu You at the Chinese Academy of Geological Sciences in Beijing said that the fine sediment the finds had been covered with by the lake in which the birds died explained the "very, very beautiful preservation"