Beipiaosaurus

Beipiaosaurus inexpectus was a therizinosaur , a mysterious group of theropods. The exact classification of therizinosaurs is open to debate, since their prosauropod-like teeth and body structure indicate that they were herbivorous, unlike all other theropods. The discovery of Beipiaosaurus, a therizinosaur with feathers, is further evidence that therizinosaurs were therepods, as only theropod dinosaurs are so far known to have been feathered.

Beipiaosaurus measured 2.2 metres in length, and is the largest known feathered dinosaur. Fossils found in China show that its body was covered by downy feather-like fibres, which are very similar to those of Sinosauropteryx.