Sinornithosaurus Probably Wasn’t Venomous After All
by Brian Switek
Every now and then, I come across a study that makes me hope my first doubtful impression is wrong and that the authors have better evidence to back up their claims. One such case was the hypothesis that the feathered dinosaur Sinornithosaurus had a venomous bite, as was proposed by scientists Enpu Gong, Larry Martin, David Burnhamb and Amanda Falk several months ago.
The idea was more interesting than it was well-supported, and now, in the journal Paläontologische Zeitschrift, paleontologists Federico Gianechini, Federico Agnolin, and Martin Ezcurra have confirmed my suspicions about the “venomous dinosaur” idea.
The hypothesis of a venomous Sinornithosaurus was based upon three lines of evidence—apparently long teeth in the upper jaw, grooves in those teeth which could conduct venom, and a pocket in the skull said to be the perfect spot for a venom gland. As Gianechini and colleagues argue, however, all of these features have other explanations that have nothing to do with venom. First, the “elongated” teeth. Rather than being exceptionally long, it appears that the teeth of the Sinornithosaurus Gong and colleagues used in the study had slightly slipped out of their sockets. Sinornithosaurus did not have extraordinarily lengthy fangs…