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.
Camouflage 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 Dromaeosaurs. 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.
Scientific name: Sinornithosaurus
Discover what these behaviours are and how different plants and animals use them.
Additional data source: Animal Diversity Web
Discover the other animals and plants that lived during the following geological time periods.
Learn more about the other animals and plants that also form these fossils.
Sinornithosaurus (derived from a combination of Latin and Greek, meaning 'Chinese bird-lizard') is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (early Aptian) of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.
Xu Xing described Sinornithosaurus and performed a phylogenetic analysis which demonstrated that it is basal, or primitive, among the dromaeosaurs. He has also demonstrated that features of the skull and shoulder are very similar to Archaeopteryx and other Avialae. Together these two facts demonstrate that the earliest dromaeosaurs were more like birds than the later dromaeosaurs were. This talks against one argument made by critics of the theory that birds evolved from dinosaurs, namely that the most birdlike dinosaurs are predated by the earliest birds (see temporal paradox).
Sinornithosaurus was among the smallest dromaeosaurids, with a length of about 90 centimetres (3.0 ft).