tooth and a bone from a skull were discovered a few hundred meters away, and an as-yet unidentified tooth has been found about 100 meters away.
The precise family tree of modern humans is contentious, and so far, no one knows exactly how .
Carbon dating stone tools
“The whole site’s surprising, it just rewrites the book on a lot of things that we thought were true,” said geologist Chris Lepre of the Lamont-Doherty Earth Observatory and Rutgers University, a co-author of the paper who precisely dated the artifacts.
The tools ”shed light on an unexpected and previously unknown period of hominin behavior and can tell us a lot about cognitive development in our ancestors that we can't understand from fossils alone,” said lead author Sonia Harmand, of the Turkana Basin Institute at Stony Brook University and the UniversiteÌ Paris Ouest Nanterre.
Scientists working in the desert badlands of northwestern Kenya have found stone tools dating back 3.3 million years, long before the advent of modern humans, and by far the oldest such artifacts yet discovered.
The tools, whose makers may or may not have been some sort of human ancestor, push the known date of such tools back by 700,000 years; they also may challenge the notion that our own most direct ancestors were the first to bang two rocks together to create a new technology.
Potts said he had examined the stone tools during a visit to Kenya in February.
“Researchers have thought there must be some way of flaking stone that preceded the simplest tools known until now,” he said.
But using a stone for multiple purposes, and using one to crack apart another into a sharper tool, is more advanced behavior.
The find also has implications for understanding the evolution of the human brain.
The toolmaking required a level of hand motor control that suggests that changes in the brain and spinal tract needed for such activity could have occurred before 3.3 million years ago, the authors said.