From: Herald Sun
April 09, 2010
SCIENTISTS believe they have discovered a crucial missing link between apes and humans.Two 1.95 million-year-old skeletons found in a South African cave are believed to belong to a previously unknown species.
Experts said the discovery could rewrite the story of human evolution.
Melbourne University played a crucial role in dating the fossilised remains of the adult woman and child.
Dr Robyn Pickering used uranium-lead dating techniques to establish the approximate age of layers of rock holding the partial skeletons.
Melbourne University is one of only two institutions in the world capable of such work.
Dr Pickering, a world leader in geochronology, was part of an international panel of more than 60 experts who collaborated on the project.
A team led by Prof Lee Berger, from the South African University of Witwatersrand, found the skeletons in 2008, among mining debris in South Africa's "cradle of humankind" World Heritage site.
"He was so excited when he made the discovery, he ran to the top of a hill to get mobile phone coverage and called me in Switzerland," Dr Pickering said. "It was such an amazing discovery, I just had to be part of it."
Experts believe the new species may be a missing link between Australopithecus and the predecessor to modern humans, Homo erectus.
The new species, dubbed Australopithecus sediba, sports ape-like features along with characteristics of species of early man.
The two humanoids are believed to have died after falling 50m into a deep cave.
Data gleaned from their skeletons, believed to be the most complete yet discovered, revealed the species walked upright and was about 1.27m tall.
They also shared many physical traits common to early humans, including a prominent nose and powerful hands capable of using stone tools.
While its brain was still relatively small, Au. sediba had long legs and an advanced hip and pelvis, enabling it to walk in a way similar to modern humans.
Prof Berger said sediba, "natural spring" in the Sotho language, seemed appropriate for a species that might be the point at which the beginnings of modern humans sprang forth.
"The newly documented species appears to be very good transitional form, maybe the best yet found, between Australopithecines and early members of the genus homo," he said.
The species occurred at a transition from small-brained bipedal apes to larger-brained ancestors of modern humans.
"The discovery of so many partial skeletons from a single site is unprecedented," Prof Berger said. "It enables us to understand the full skeletal anatomy of these early human ancestors rather than relying on fragments of a skull or some teeth, which can sometimes be misleading."
The findings are detailed in the latest edition of Science.