A series of studies released today show that a long-extinct South African creature had an intriguing mix of human and apelike traits. But scientists say they still haven’t figured out where it fits on our evolutionary family tree. The human branch of the evolutionary tree, called Homo, is thought to have arisen from a group of ancient species called australopithecines. The newly studied species is a member of this group, and so its similarities to humans are enticing for tackling the riddle of how Homo appeared.