Skeletons of Australopithecus sediba display a unusual mix of modern and primitive traits - sharing more features with early Homo specimens than any other known Australopithecus species, according to Darryl de Ruiter of Texas A&M University in College Station, USA.
     Researchers found the remains of at least four individuals - a youth, an older female, an 18-month-old infant and at least one other adult - who died when they fell into a 'death trap' in a cave about 2 million years ago at Malapa (South Africa).
     These particular individuals could not be ancestors of Homo because members of our genus were already living at the time when they fell into the pit. But, says Lee Berger of the University of the Witwatersrand in Johannesburg (South Africa), they might be late members of the australopithecine species that earlier gave rise to Homo, or a close relative that could shed light on that crucial ancestor.
     Anthropologists have long wondered which of several species of Australopithecus gave rise to the first members of our genus - with Lucy's north African species,  Australopithecus afarensis, as the leading candidate - and evidence is accumulating that the South African species formed an evolutionary connection between relatively apelike members of Australopithecus, and the Homo genus, which includes living people.
     Much uncertainty surrounds the identity of fossil members of the human evolutionary family between 3 million and 2 million years ago, says John Hawks of the University of Wisconsin, Madison (USA).

Edited from ScienceNews (18 April 2011), Science (19 April 2011), PhysOrg (20 April 2011)