Bunostegos was a large, ugly reptile that lumbered around 250 million years ago, and newly-discovered fossil of the reptile from northern Niger in Africa is now teaching scientists about the ancient supercontinent of Pangea.
"Imagine a cow-sized, plant-eating reptile with a knobby skull and bony armor down its back," said lead author of study detailing the findings Linda Tsuji.
Bunostegos is a type of pareiasaur, a large, plant-eating reptile that was found in many regions across Pangea. While its physical features might suggest more evolution, scientists found Bunostegos to be more primitive than some other pareiasaurs. This means two things: convergent evolution and isolation.
Bunostegos is believed to have mostly roamed around in central Pangea, a region that was hyperarid, or super dry. Scientists still aren't quite sure about the reptile's social behaviors, or the size of its territories, but if in fact Bunostegos evolved the way researchers believe it did, then it provides evidence that Pangea, despite being one huge continent, was divided through means outside of typical topographical landmarks.
"Our work supports the theory that central Pangea was climatically isolated, allowing a unique relict fauna to persist into the Late Permian," said Christian Sidor, another author of the paper.
It is believed that the incredibly hostile living conditions of central Pangea not only kept outside animals from passing through, it kept those accustomed to its heat and dryness inside, creating a natural fence and incubator.
You can read the full published study, titled "The vertebrate fauna of the Upper Permian of Niger - VII. Cranial anatomy and relationships of Bunostegos akokaensis (Pareiasauria)" in volume 33, issue 4 of the Journal of Vertebrate Paleontology.