The skeletons of Australopithecus sediba.The more complete skeleton of the adolescent male (MH1) is on the left, and the less complete adult (MH2) is on the right. From Berger et al, 2010.

From 3.8 million years ago, the ancestral species is the oldest known member of Australopithecus, the grouping of creatures that preceded our own branch of the family tree, called Homo.