Fossils of these miniature, fanged plant-eaters known as heterodontosaurs, or "different toothed reptiles," have turned up as far apart as England and China. Now, in a discovery that has been at least 50 years in the making, a new and especially bizarre species of these dwarf herbivores has been identified in a slab of red rock that was collected in the early 1960s by scientists working in South Africa.
In a report published Wednesday in the online journal ZooKeys, Paul C. Sereno, a paleontologist at the University of Chicago and a dinosaur specialist, described the strange anatomy of the newfound member of the heterodontosaur family and gave the new species the name Pegomastax africanus, or "thick jaw from Africa."
He also apologized for not getting around sooner to this piece of research. When he first viewed the specimen at a Harvard laboratory, Sereno said, "My eyes popped, as it was clear this was a distinct species."
The creature in the lab drawers
Embedded in the rock were remains of a creature with a short parrotlike beak, 1-inch jaws, sharp teeth and a skull no less than 3 inches long. It was two-legged, had grasping hands "and was mostly tail and neck," Sereno said. The entire body was less than 2 feet in length and probably weighed a bit more than a typical house cat.
"I'm embarrassed to say how many years ago that was -- 1983," he said. "But I was an enterprising graduate student then at the American Museum of Natural History. All the while since then, I wondered if anyone else might spot the creature hiding among the lab drawers."
The fossils were eventually returned to the South African Museum in Cape Town, the true nature of the one slab still undiscovered, Sereno said. The main researcher responsible for collecting the fossils was Alfred Crompton, a Harvard professor now retired. Part of Sereno's research was supported by the National Geographic Society, where he also is an explorer-in-residence.
What big teeth you have
Sereno's examination showed that behind the parrot-shaped beak were a pair of stabbing canines up front and a set of tall teeth tucked behind for slicing plants. "It would have looked like Dracula," he told LiveScience.
These teeth in upper and lower jaws operated like self-sharpening scissors, Sereno said, with shearing wear facets that slid past one another when the jaws closed. The parrotlike skull, he noted, may have been adapted to plucking fruit.
He said it was "very rare that a plant-eater like Pegomastax would sport sharp-edged enlarged canines." Some scientists suggested that the creature may have consumed some meat, or at least insects. But Sereno concluded that the creature's fangs were probably "for nipping and defending themselves, not for eating meat."
He said, and "their anatomy is key to understanding the early evolution of this great group of plant-eaters."
Another possible characteristic of the new species, Sereno said, is that its body might have been covered in quills, something like that of a porcupine. If so, he pictured that in life Pegomastax would have scampered around in search of suitable plants, looking something like a "nimble two-legged porcupine."