In a fascinating discovery that will force scientists to rewrite our species’ evolutionary history, an international team has unearthed the earliest known skull of Homo erectus – the first of our ancestors to be nearly human-like which is dated to be two million years old.
What is really exciting is that during the same time in history, there were three very different types of ancient human ancestors roaming the same small landscape.
The skull was discovered by the team of 30 scientists from five countries – including Arizona State University researcher Gary Schwartz – at the fossil-rich site of Drimolen within the Cradle of Humankind which is a UNESCO World Heritage site near Johannesburg, South Africa.
“Unlike the situation today, where we are the only human species, two million years ago our direct ancestor was not alone,” said Andy Herries, project director and lead researcher from La Trobe University in Australia.
The skull, reconstructed from more than 150 separate fragments, is of an individual likely aged between three and six years old, giving scientists a rare glimpse into childhood growth and development in these early human ancestors.
Additional fossils recovered from Drimolen belong to a different species – the more heavily built, robust human ancestor Paranthropus robustus and a third, distinctive species called Australopithecus sediba.
“We don’t yet know whether they interacted directly, but their presence raises the possibility that these ancient fossil humans evolved strategies to divvy up the landscape and its resources in some way to enable them to live in such close proximity,” explained paleoanthropologist Schwartz.
The discovery allows scientists to address what role changing habitats, resources, and the unique biological adaptations of early Homo erectus may have played in the eventual extinction of Australopithecus sediba in South Africa.