Six scientific articles published today in the journalSciencebring us closer to understanding an ancestor of human beings, Australopithecus sediba, who lived in southern Africa two million years ago and whocould help solve the riddle about how the Homo branch appeared, to which we belong.
A. sedibait was a species “half monkey, half human”, according to the researchers, among other things because it climbed trees with the same ease with which it walked upright. Added to this is that the upper part of its thorax was very narrow, similar to that of orangutans, chimpanzees or gorillas, while the lower part had a morphology similar to that of humans. Regarding locomotion, they walked with their legs fully extended but with their feet inverted, excessively tilted to one side when walking. That, coupled with excessive knee rotation, and a narrow ape-like heel, made his bipedalism very different from ours.A. sediba walked like no other animal, say the scientists, who suspect that the creature touched the ground first with the side of the foot, which then turned inward in a movement called pronation.
On the other hand, the species had a relatively small brain, an almost human pelvis, and a mixture of monkey and man in the jaw and teeth. The arms were specifically adapted for climbing, from which it follows that the use of the front of the arm to grasp and manipulate objects emerged later, possibly with Homo erectus, notes the team led by Steven Churchill of Duke University in Durham.
In short, the fossils, found in the Malapa cave, revealan unexpected “mosaic of anatomies”, as Jeremy DeSilva, a Boston University researcher and lead author of one of the papers, has expressed.
