A dromaeosaurid dinosaur with a filamentous integument from the Yixian Formation of China

Dromaeosaurids, despite their notoriety, are poorly characterized meat-eating dinosaurs, and were previously known only from disarticulated or fragmentary specimens1. Many studies have denied their close relationship to birds2,3. Here we report the best represented and probably the earliest dromaeosaurid yet discovered, Sinornithosaurus millenii gen. et sp. nov., from Sihetun, the famous Mesozoic fish–dinosaur–bird locality in China4,5....