The latest issue of Science, just published, devotes several papers to a consideration of Australopithecus sediba, a species identified in southern Africa and dated to between 1.95 and 1.76 million years ago. When the species was identified in 2008 I wasn't much interested because the genus Homo was already perhaps a million years old by then, so this finding seemed to outside the human lineage. There were many bipedal apes three million years ago and even after the emergence of Homo bipedal apes persisted. The new Science issue considers the possibility that A. sediba led into Homo as we now know it.
A study made of the interior of a very well preserved juvenile cranium shows that the brain was much smaller than those of Homo species but suggests that the brain was being rewired in direction of the modern frontal lobe. Now there is a surprise. If true, it suggests a double story—brain growth which had begun with Homo continued with a reorganized brain from last Australopithecus.
Another surprise, the A sediba pelvis included modern features that are usually explained as adaptations to allow for the birth of a big-brained infant. But sediba did not have big-brained infants. So why had its pelvis shifted?
The hand fossil is the most complete such fossil from the period we have yet. Details suggest both tree climbing and a precision grip. Such hands could have been used for making tools.
A well preserved ankle suggests a human like arched foot with a heel more typical of apes.
All of these suggestions are quite important, if true.