First venomous dinosaur

Following their examination of a well-preserved skull from the Chinese dromaeosaurid dinosaur Sinornithosaurus, a scientific team led by Empu Gong reported in 2009 that this dinosaur possessed several features indicating that it was venomous, including prominent grooves running down the outer surface of its unusually long, fang-like mid-jaw teeth. This is the first time that evidence for venom production by a dinosaur had ever been put forward with the findings published in the journal PNAS on 12 January 2010. The Sinornithosaurus dates from the Early Cretaceous Period (146 million to 120 million years ago).

Later in 2010, a separate team (Gianechini, F., Agnolín, F., & Ezcurra, M.) rebutted this claim in the journal Paläontologische Zeitschrift, but their rebuttal was countered by a comprehensive response from Empu Gong's team, in which they also revealed that several presently undescribed specimens of this same dinosaur shared the venomous features that they had recorded for the specimen examined by them in 2009.