A new species of dinosaur has been unveiled – the Pegomastax africanus, a 200-million-year-old dinosaur – and it is the subject of a new peer-reviewed research paper in the journal ZooKeys. The fossils were discovered in South Africa (around and in Lesotho) 50 years ago.

University of Chicago paleontologist Paul Sereno published the findings on Wednesday, and told Reuters he actually made the discovery of the cat-sized dinosaur in 1983. He came across the specimen while he was a graduate at Harvard, and had planned to publish something on it right away.  “I said, ‘Whoa!’ I realised it was a new species from the moment I set eyes on it,” Sereno said. But scientists are busy guys, and he became distracted with another more ambitious project, and the Pegomastax africanus, or ”thick jaw from Africa” lay forgotten for three decades. “There was always a danger that someone would discover it and write about it, and I would read about it,” he said.

The little dinosaur – one of the smallest ever discovered – was less than two feet (0,6 meters) long and weighed less than a house cat at 6,8 kilograms at most, “and was mostly tail and neck,” Sereno added. Strangely, bristles somewhat like porcupine quills may have spread across most of the body of Pegomastax. Serano said:

It would have looked a bit like a two-legged porcupine, covered in these weird, funky, quill-like things. The bristles were not quite as strong as a porcupine’s, and they don’t look as if they were especially effective for insulation. Perhaps they had colors and helped differentiate species, or made Pegomastax look bigger than it actually was to potential predators.

Extending from its parrot-beaked skull, which was less than two inches (five centimeters) long, were serrated canines a half-inch (0,8 cm) long from both its upper and lower jaws. When the jaws closed, the fangs slid into sockets in the opposing jaws instead of sliding past one another for the optimised cutting or gripping you expect from some carnivorous beasty. However, Serano believes that the Pegomastax ate mainly plants and nuts. He said that:

The canines probably had nothing to do with meat-eating . . . They may have been used to spite rivals, nip at others, defend themselves, maybe root around for food.

Tall teeth in the back of the jaw probably helped slice plants, with surfaces that slid past one another when the jaws closed, operating like self-sharpening scissors. “Pegomastax and kin were the most advanced plant-eaters of their day,” Sereno said.

The fossil was originally chipped out in the 1960′s out of red rock near the border of Lesotho and South Africa by Harvard researchers.

[Sources: TimesLIVE, Live Science]