An international team of researchers have unearthed tens of thousands of Earlier Stone Age artifacts at an archaeological site in Kathu, Northern Cape province of South Africa.

Archaeologists from the University of Cape Town, University of Toronto (U of T) and the McGregor Museum in Kimberley, South Africa, discovered hand axes and other tools at the Kathu Townlands site that is between 700,000-1 million years old.

Steven James Walker, from the Department of Archaeology at UCT and lead author of the study, said that Kathu is a major iron mining centre at present. The prehistoric site is the middle of an intensive development phase, posing a unique challenge for archaeologists and developers to collaborate together.

"The site is amazing and it is threatened. We've been working well with developers as well as the South African Heritage Resources Agency to preserve it, but the town of Kathu is rapidly expanding around the site. It might get cut off on all sides by development and this would be regrettable," Walker said in a statement.

The Kathu Townlands site is one among a group of prehistoric sites known as the Kathu Complex. Other sites in the group include Kathu Pan 1 that has generated fossils of animals like elephants and hippos, and tools dating back to half a million years ago.

"We need to imagine a landscape around Kathu that supported large populations of human ancestors, as well as large animals like hippos. All indications suggest that Kathu was much wetter, maybe more like the Okavango than the Kalahari. There is no question that the Kathu Complex presents unique opportunities to investigate the evolution of human ancestors in Southern Africa," said Michael Chazan, Director of the Archaeology Centre at U of T.

The finding is published in the journal PLOS ONE.