There weren't many skin treatment solutions that we know of some 266 to 252 million years ago. But even if there had been, they wouldn't have been able to help Bunostegos akokanensis, a giant, plant-eating reptile that roamed the central deserts of the then-single continent of Pangea. Three recently discovered fossilized skulls of this ancient animal, dug up in Niger, Africa, are covered by numerous bony protrusions resembling a bad case of acne. But the bumps, the largest of their kind ever seen on this type of animal, were most likely skin-covered horns like those on modern giraffes, according to a new analysis by scientists from the US, South Africa, and Niger. They weren't necessarily a form of protection — instead, scientists think they served as identifying marks for the species and for individual dinosaurs, according to the BBC.

More importantly, the analysis of the skulls revealed cranial features that more closely resembled even older reptiles. That lead the scientists to conclude that Bunostegos, along with other species of its time, evolved in isolation in the central desert of Pangea, separated from the rest of the continent by natural barriers, namely the dryness of the region compared to the rest of its surrounds. This allowed the knobby-headed reptile and other animals in the central desert region to develop unique characteristics compared to their cousins outside the desert. The findings should help scientists better understand how species evolved during the Perian period, and were published today in the Journal of Vertebrate Paleontology.