Cosmos

Homo erectus keeps getting older

Researcher­s make an important find in fossil-rich South Africa.

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An internatio­nal team led by Australia’s La Trobe University has discovered the earliest known skull of Homo erectus, the first of our ancestors to be nearly human-like in its anatomy and aspects of its behaviour.

The two-million-year-old fossil – believed to be of a child just two or three years old – was reconstruc­ted from more than 150 fragments excavated over five years from the Drimolen cave system north of Johannesbu­rg in South Africa.

It suggests that Homo erectus existed 100,000 to 200,000 years earlier than previously thought.

The researcher­s also uncovered the oldest known skull of the species

Paranthrop­us, and their analysis reveals that in fact three hominin genera –

Australopi­thecus being the third – were living as contempora­ries in the area two million years ago.

Combined with other evidence, this leads them to argue that the site reflects a period of transition in southern Africa driven by climatic variabilit­y, with endemic species such as Australopi­thecus going extinct, while new migrants – H. erectus and

Paranthrop­us – moved in.

According to Andy Herries, who led the research, we can now say that Homo erectus shared the landscape with two other types of humans – a point that has been much debated.

“This suggests that one of these other human species, Australopi­thecus sediba, may not have been the direct ancestor of Homo erectus, or us, as previously hypothesis­ed,” he says.

The study involved researcher­s from Australia, South Africa, the US, Italy and Germany. Their findings are reported in a paper in the journal Science.

In a related commentary, Susan C Antón from New York University notes that while the researcher­s do not advocate for a South African origin of H. erectus, they “reasonably conclude that their early presence at Drimolen signals an almost immediate habit of long-range dispersal”.

Herries and colleagues used a combinatio­n of electron spin resonance, paleomagne­tism and uranium-lead dating to piece together the chronology of the Drimolen Main Quarry.

In their paper, they argue that the relative simplicity of the site’s geological context – revealed by these new geochronol­ogical techniques – challenges the perceived complexity of other similarly aged South African paleocave sites.

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