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New Early Human Identified

Image of skull of Homo gautengensis

Partial reconstruction of a skull of Homo gautengensis, a two million year old human species. Credit: Darren Curnoe

By Stephen Luntz

The human family tree is turning bushy with the announcement of yet another new species named Homo gautengensis by University of NSW anthropologist Dr Darren Curnoe.

H. gautengensis lived around the same time and place as “the missing link” Australopithecus sediba (AS, June 2010 pp.14–17), and is a closer relative of ours, belonging to our genus. Nevertheless, publication of the finding in HOMO – Journal of Comparative Human Biology has aroused much less media interest than A. sediba, which Curnoe attributes to the new species being a reclassification of previously known fossils rather than a new find.

Bones that Curnoe has now identified as being from H. gautengensis were found as early as the 1940s. In the 1970s more were found, and they were recognised as being from the Homo family. However, South Africa was isolated at the time by the scientific boycott of Apartheid and progress was slow. Even today Curnoe says “there are far more scholars working in East Africa and Europe” on early human remains than in southern Africa.

In the 1990s Curnoe classified these bones as coming from Homo habilis. However, he has now concluded that H. gautengensis ate a different diet from H. habilis, and was sufficiently different to deserve categorisation as a new species.

The classification makes H. gautengensis the oldest known species of Homo. However, it’s unlikely to be the original member of the genus. Fossils from East Africa that clearly belong to the Homo genus, but have yet to be assigned to a specific species, are up to 300,000 years older than the two million-year-old H. gautengensis skulls, jaws, teeth and other bones Curnoe that worked on.

“The most likely thing is that Homo evolved in East Africa and spread to southern Africa where the species diverged,” says Curnoe. “So this is not a direct ancestor – more of a close relative of our ancestors at the time.” Curnoe has found 40 features that indicate his species belong in the Homo genus, notably the small teeth, jaws and chewing muscles.

H. gautengensis appears to have used fire and quite sophisticated tools for the time. Curnoe says there is some evidence that animal bones were cooked in the campfires. The bones were found in the Sterkfontein and nearby caves, along with Australopithecus bones, but Curnoe doubts either species lived there, suspecting these were death traps or that the bones washed there after death.

The discovery of so many new human species may force a rethink of how we come to be unique today. “We don’t know if we wiped our relatives out or if we were lucky enough to survive climate change at the end of the last ice age and other species were not,” Curnoe says.