Most complete feathered dinosaur fossil

In April 2001, a complete fossil of Sinornithosaurus millenii, a relative of the Velociraptor, was discovered by farmers at the Yixian Formation fossil bed in Liaoning Province, China. It is completely covered in downy fluff and primitive feathers and was found between two slabs of fine grained rock estimated to be 130 million years old. It resembles a large duck with a long tail and is approximately 60 cm (2 ft) long.

This is the first time a complete feathered fossil has been found, greatly supporting the theory that present day birds evolved from ancient reptiles. It was analysed by Mark Norrell (American Museum of Natural History, New York) and ji Quiang (Chinese Academy of Geological Sciences) and was reported in the journal Nature.

Sinornithosaurus belongs to a class of dinosaur known as dromaesaurs, which were small, fast-running predators. Like the Velociraptors, they had a sharp sickle-like claw on the middle toe and rods in the tail for balance.