A stone tool discovered in Turkey, believed to be the oldest ever uncovered, is proof humans migrated through a gateway between Asia and Europe 1.2 million years ago, much earlier than previously believed, scientists say.
A quartzite flake, showing unmistakable signs of being worked by humans into a cutting tool, provides a new understanding of how and when the dispersal of early humans out from Africa and Asia took place, a team of international researcher says.
Writing in the journal Quaternary Science Reviews, the researchers describe how they used sophisticated techniques to date the ancient deposits from the river Gediz in what is today western Turkey where the tool was found.
"This discovery is critical for establishing the timing and route of early human dispersal into Europe," says Danielle Schreve of the Royal Holloway, University of London. "Our research suggests that the flake is the earliest securely-dated artifact from Turkey ever recorded and was dropped on the floodplain by an early hominin well over a million years ago."
Many flaked tools have been found in Turkey, but most were unearthed in sediments for which reliable dates could not be established.
The only other evidence of early human presence in the region is an ancient skull that was uncovered in Kocabaş, Turkey, but its age is uncertain, with the best estimates putting it at between 1.3 and 1.1 million years old.
However, highly precise radioisotopic dating and palaeomagnetic measurements of ancient lava flows allowed the dating of the Gediz riverbed, suggesting human were living in the region between around 1.7 million and 1.24 million years ago.
Other artifacts previously found in the Gediz valley had brought Schreve and her fellow researchers to the ancient riverbed for a closer look.
"The flake was an incredibly exciting find," Schreve says. "I had been studying the sediments in the meander bend and my eye was drawn to a pinkish stone on the surface. When I turned it over for a better look, the features of a humanly-struck artifact were immediately apparent."
"By working together with geologists and dating specialists, we have been able to put a secure chronology to this find and shed new light on the behavior of our most distant ancestors," she says.
The oldest stone tools ever found -- about 2.6 million years old -- were from Africa in the Olduvai Gorge in Tanzania.
