Archaeologists working in the Kenyan Rift Valley have discovered the oldest known stone tools in the world. Dated to around 3.3 million years ago, the implements are some 700,000 years older than stone tools from Ethiopia that previously held this distinction. They are so old, in fact, that they predate the earliest fossils representing our genus, Homo,by half a million years. As such they suggest that stone tool manufacture began not with Homo, but with a more primitive member of the human family.
A happy accident led to the discovery of the ancient tools. Sonia Harmand of Stony Brook University and her team had been en route to a known fossil site on the western shore of Lake Turkana one morning in July 2011 when the group took a wrong turn and ended up in a previously unexplored area. The researchers decided to survey it and by teatime they had found stone artifacts. They named the site Lomekwi 3, and went on to recover dozens of tools—including flakes, cores and anvils–from both the surface and below ground. Harmand described the findings April 14 in a talk given at the annual meeting of the Paleoanthropology Society in San Francisco.