Zhenyuanlong

Zhenyuanlong is a genus of dromaeosaurid dinosaur from the Yixian Formation of Liaoning, China. It lived in the early Cretaceous period, about 125 million years ago. 
There is just one specimen. It is estimated the skeleton would have been about 165 centimetres (5.41 ft) long when complete. That means the animal was too large to have flown, especially since early flight was, almost certainly, less efficient than the flight of modern birds. It would surely have looked more like a bird than a modern reptile. This is shown in most reconstructions of dinobirds.
This type specimen has a nearly complete skeleton with traces of feathers, including long tail feathers and large wings. This specimen is the first evidence of well-developed feathers in a large, non-flying dromaeosaur. The feathers probably had two functions: temperature control and signalling.