ScienceShot: When Fanged Dwarf Dinosaurs Roamed the Earth

Some dinosaurs were weirder than others. Long before Stegosaurus and Triceratops stomped the earth, heterodontosaurs scampered about the supercontinent Pangaea armed with porcupinelike bristles and sharp, protruding fangs. The housecat-sized family has been the source of debate for decades. Because heterodontosaurs' prominent canines resembled those of carnivores, some paleontologists have argued that the creatures supplemented their plant-based diets with insects or small animals. Others have claimed that the vampire fangs were mostly for show, used to spar with rivals for mates or to scare away predators. Now Pegomastax africanus may settle the question. This 2-foot-tall genus of heterodontosaur—which was unearthed in the 1960s but languished in a museum drawer until now—has a parrotlike skull and the genus's distinctive fangs. But microscopic analysis of the wear marks on its teeth and a reconstructed flesh model of its close cousin, Heterodontosaurus, suggest it used its mighty choppers to nip and spar, and not for wholesale meat-eating, researchers report online today in ZooKeys. By filling in more of the heterodontosaur family tree, the rediscovered Pegomastax could shed light on the family's origins, and why they declined and disappeared long before dinosaurs as a whole went extinct.

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Posted in Plants & Animals