The ancient supercontinent Pangaea had a vast desert located about where Northern Africa exists today. A new fossil find, belonging to a reptile with a most peculiar appearance, offers evidence that within this ancient arid climate was a desert oasis that bore great species diversity.
Linda Tsuji from the University of Washington authored the study that described the recent fossil discovery in the Journal of Vertebrate Paleontology.
Bunostegos akokanensis was a 260-million-year old reptile as big as a cow with distinctive scaly knobs on its head. It belonged to a group of prehistoric reptiles known as the pareiasaurs. These plant-eating beasts ranged in size from 2 to almost 10 feet, and had short tails, small heads, and stocky limbs. They also have characteristic knobs and crests on their head—but none as big as Bunostegos’. Paleontologists think pareiasaurs used head protrusions to differentiate between species.
Bunostegos’ cranial bones were found in Northern Niger, where, 260 million years ago, an immense desert stretched out, with climates so hot and dry it was difficult for all but the hardiest plants and animals to survive. But Bunostegos somehow subsisted, and maybe others in its ecosystem were thriving too.
Tsuji’s team compared Bunostegos’ fossils to those of other pareiasaurs, and found, to their surprise, Bunostegos was closest to older, more primitive pareiasaurs. They think, because this species lived in the middle of the Pangaea desert, its lineage was isolated and it evolved independently from other pareiasaurs. Bunostegos probably inhabited an area where the climate was not so harsh and the ecosystem wasn’t so dry—an oasis surrounded by desert where limited exchange occurred in and out. This could explain why its head has such prominent features not seen on other species.
Find the description of Bunostegos in the June 25, 2013 issue of the Journal of Vertebrate Paleontology.
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