Fossil shows "knobby-headed" reptile wandered ancient Earth Artist's impression of knobby-headed reptile. Credit: University of Washington SEATTLE, June 25 (UPI) -- U.S. paleontologists say a bizarre reptile with knobbly growths on its head roamed a vast, isolated desert about 260 million years ago. New fossils from northern Niger in Africa are those of a creature belonging to a new genus of pareiasaur, plant-eating creatures that flourished during the Permian period when the Earth was dominated by a single supercontinent called Pangaea, Linda Tsuji from the University of Washington said. The cow-sized reptile has been named Bunostegos, for "knobby roof." Bony knobs on the skull were a feature of most pareiasaurs, Tsuji said, but those of Bunostegos are the largest ever seen. The bony protrusion were most likely skin-covered horns like those seen on the heads of modern giraffes, she said. "We can't say for sure, but it is most likely that the bony knobs on the skull of pareiasaurs did not serve a protective function," Tsuji told BBC News. They vary quite markedly in size and shape between different species, with some species lacking prominent knobs entirely, so I think that they were purely ornamental.