September 09, 2011
NEW testing on prehistoric skeletons found in South Africa has found they are 2 million years old -- providing compelling evidence the discovery could be mankind's earliest known ancestor.
An international research team determined the age of the primitive human remains using uranium-lead dating and analysis of the flowstone surrounding them at the excavation site.
The age of the skeletons, named Australopithecus sediba -- meaning "natural spring" in the South African language of Sotho -- puts forward a strong case for the hominids being the missing link between man and ape.
The fossils were found in 2008 at the Malapa Cave site -- in an area known as the Cradle of Humankind, west of Johannesburg -- and were brought to the world's attention last year by Professor Paul Dirks from Australia's James Cook University in Townsville and Professor Lee Berger, from the University of Witwatersrand.
Their work is being published this week in a series of five papers in the international journal ‘Science’.
Until now fossils dated to 1.9 million years ago, including Homo habilis and Homo rudolfensis, were considered ancestors of Homo erectus, the earliest undisputed human ancestor.
"We are able to say far more definitely that we have a lot of very good evidence that these fossils are older than Homo erectus," Dirks said.
"Last year, we got a bit of criticism from people who said we weren't certain about the age of the fossils and there was an overlap with the Homo erectus fossils. But this year, we can be far more definite."
There have now been six skeletons unearthed at the cave -- including what appears to be a family of five with a male adult, a female adult, a juvenile, a small child and a baby.