Bunostegos Akokonensis is Really a Quadruped?

Previously thought to have slithered on its stomach like its prereptile cousins, Bunostegos akokanensis, or the prehistoric cow, is now believed to have been a quadruped, according to scientists at Brown University. The discovery is unusual, as all fossils of this time period indicate that prereptiles had moved around by sprawling out on the ground or by walking upright on two feet. It wasn’t until years later that species, like the Bunostegos akokanensis, were found to be able to stand on four legs. Findings such as this completely change what researchers have come to understand about the evolution of limbs.

Bunostegos akokanensis

According to researchers, Bunostegos akokanensis – classified as a pareiasaur and a herbivore – had lived during the Permian era, about 250 billion years ago. Its nickname, the prehistoric cow, was inspired by its sheer size and bovine-like shape, which can be characterized by a small head, wide feet, and a short tail. Its fossils were first discovered in Niger, Africa by paleontologist Linda Tsugi, who co-authored this study in 2003.

What The findings Reveal

Upon the discovery of the fossils, Tsugi presumed that the species had limbs that were split out by its sides and jointed past the elbow. However upon further investigation, researchers, in conjunction with Brown University, found that the forelimb was very different than that of an animal who moves around by sprawling on the ground. The desert habitat during the Pangaea era may have contributed to the Bunostegos akokanensis’ quadriped capabilities. Navigating upright on all fours would have been the most efficient way for the creature to move. This would have helped them conserve energy, especially during periods of time when food could not be found.

What this means for evolution

The finding reveals that upright quadrupedalism may have evolved earlier than previously thought. Scientists believe that Bunostegos akokanensis will help them learn more about the evolutionary significance of the transition from sprawling to walking.