An ugly reptile the size of a cow but with the looks of a lizard lived on the ancient supercontinent Pangaea, researchers say.
Fossils of the Bunostegos, which may have lived 260 million years ago, were found recently in northern Niger.
"Imagine a cow-sized, plant-eating reptile with a knobby skull and bony armor down its back," said lead author Linda Tsuji, of the University of Washington, in a statement.
The period was known for vast deserts and was dominated by reptiles that could survive the harsh climate conditions.
Researchers say that the finding is important not only for the fossil discovery, but also because it may give clues about Pangaea's climate. They believe that the finding adds to evidence there was a large desert in the middle of Pangaea.
The isolation in the desert region may be what makes this animal so unique.
"Our work supports the theory that central Pangaea was climatically isolated, allowing a unique relict fauna to persist into the Late Permian," said Christian Sidor, another author of the paper, in a statement.
The findings were published in the Journal of Vertebrate Paleontology.