When a perfect specimen of Sinornithosaurus, complete with feather impressions was found, it was a turning point in the study of dinosaurs. Detailed analysis showed tiny structures in the feathers almost identical to those of modern birds. Perhaps more amazingly, pigments were found that hinted at colours such as reddish-brown, yellows and black.
Camoflauge would have been useful for this metre-long raptor as it hunted the forests of the early Cretaceous Period. Sinornithosaurus was recovered from China's fossil-rich Yixian formation. It represents one of the earliest and most primitive of the Dromaeosaurus. It is also one of the most bird-like of the feathered dinosaurs ever found. Whether the grooves along the teeth suggest Sinornithosaurus was venomous is still debated. Sinornithosaurus was closely related to the more famous Microraptor.