T. Rex May Have Had Lips

Robert Reisz, a paleontologist at the University of Toronto, is challenging the long-standing image of meat-eating theropod dinosaurs such as T. rex. Specifically, Reisz suggests that theropods' teeth were not bared all the time, extending outside their mouths and fully visible whether their jaws were open or closed. Rather, these teeth were kept hidden, covered by scaly lips, he said in a presentation May 20 at the Canadian Society of Vertebrate Paleontology's annual meeting in Ontario.