Bumpy-Faced Cow-Sized Reptile Roamed the Ancient Desert

An artist's rendering of the Bunostegos and its bump-ridden face.

The face of the Bunostegos looks like it was made by a kindergartner who went wild with a tub of Play-Doh. Flaps of skin are stretched below its chin, hanging like stalactites. Hard knobs decorate its nose and forehead. As weird-looking as the animal is, it was able to live in the harsh deserts of the ancient supercontinent, Pangea.

Archaeologists at the University of Washington discovered three Bunostegos skulls in the rocks of the Moradi Formation in Niger. The details behind these fossilized remains will be published in next month's issue of the Journal of Vertebrate Paleontology.

The skulls are believed to date back to the late Permian period, more than 250 million years ago, and older than many dinosaur fossils seen today in museums.

Bunostegos, Latin for "knobby skull roof," belongs to a completely different animal group than dinosaurs, said Linda Tsuji, a postdoctoral researcher at the University of Washington who was the lead author of the journal article on Bunostegos.

"You have crocodiles and lizards that are more related to a dinosaur than this," she told ABC News.

Instead, the cow-sized Bunostegos belonged to the pareiasaur family, a group of large terrestrial herbivores.

Other pareiasaurs of that era had different facial decorations than the Bunostegos' stumpy knobs. This unique characteristic may have developed while it languished for millions of years in genetic isolation.

Central Pangea was an extremely hot and dry place. Animals that lived there were effectively fenced in because other forms of wildlife weren't likely to venture far in to the formidable climate.

"This is fauna that were in the middle of a desert," said Tsuji. "What we find here is probably very different than we would find elsewhere."

The Bunostegos' knobs were smaller than golf balls. They were not randomly scattered along the animal's head, but appeared over certain areas of the eye, nose and cheek.

Why these animals would have the knobs to begin with is still a mystery to Tsuji and her colleagues.

"As much as we suspect, [the knobs] are a species recognition thing," she said.

Though the Pangean desert was isolated from other areas, the Bunostegos did not live alone. Other fossilized creatures found in the same region include the Gorgonopsian, a mammal-like carnivore that may have been the dominant predator of the area, and multiple large amphibians with skulls measuring half a meter.

Source: http://abcnews.go.com