A new species of early human has been described this week – Australopithecus sediba. And it looks like it’s a key member of the family as it links the more archaic, small-brained ‘australopithecine’ with the more modern species of Homo. Sediba was unearthed two years ago at the somewhat aptly named site of ‘Cradle of Humankind World Heritage Site’ and its discoverer is Professor Lee Berger from the University of the Witswatersrand.
Two Sediba have been looked at by Berger and an international team of 60 researchers. The adult female and juvenile male are actually quite complete for such early specimens; they allowed Berger and his team to study their pelvis shape, spine, ankle and skulls. What’s interesting is that they have a mixture of old and new traits.
Like modern humans they had quite an upright stance, small teeth, an advance pelvis and relatively long legs. They were, however, just over 4ft tall in adulthood and had quite small brains.
The researchers have used a combination of dating techniques to get as accurate as possible an age on these creatures, including uranium-lead isotopes and palaeomagnetism. From this they believe Sediba would have lived around 1.95 million years ago. And it’s this period when the climate record changes dramatically, Africa becomes more arid. So perhaps the development of Sediba and later humans owes something to these climate changes