Cat-sized dinosaur with sharp teeth identified for first time
A strange and extremely tiny species of dinosaur with a beak-like face and sharp teeth has made its first appearance in the scientific literature.
The creature was discovered 50 years ago but forgotten since then in a fossil collection at Harvard University. It is a member of a family of small, barely studied dinosaurs called heterodontosaurs, meaning “different-toothed reptiles.â€
That description is particularly relevant for the new dinosaur, which was dubbed “Pegomastax africanus†by study author Paul Sereno, a University of Chicago paleontologist and National Geographic explorer-in-residence. The dinosaur had tiny jaws — about 1 inch in length — but sported sharp canine teeth in addition to a set of tall teeth used for cutting plants. While Sereno says it is strange for an herbivore to have a set of sharp canines, he believes they were used to scare off predators and spar with potential mating competition, not to eat meat.
As if Pegomostax’s small, beaked face and sharp teeth did not make it strange enough, Sereno believes the dinosaur was covered with porcupine-like quills as well. That idea comes from another species of heterodontosaur called Tianyulong, which was discovered in volcanic ash in China and had such bristles.
According to Sereno, Pegomostax and the other heterodontosaurs lived roughly 200 million years ago — about the time that Pangaea was beginning to split in two. That may explain the differences between species discovered in the north, like Tianyulong, which has triangular teeth, and southern species like the newly discovered Pegomostax, which Sereno says had a distinctively taller crown, as shown in the drawing above.
The Pegomostax remains were originally discovered about 50 years ago in South Africa in a piece of red stone, but they disappeared into a fossil archive at Harvard for many years without being described.
Sereno’s study appeared Wednesday as part of a lengthy monograph on the rarely studied heterodontosaurs in the online journal ZooKeys; the monograph is freely available here.
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