An international team of researchers has reported the discovery of with stone tools dated to between 2 and 1.8 million years old in a new site within Tanzania’s Ewass Oldupa. That is the western area of Oldupai Gorge, a 28-mile-long canyon known for its hominin fossils, including the first recognized remains of Homo habilis. The most recent stone artifacts were found in layers of stratified sediments which helped determine that the tools are the oldest stone tools found in the gorge to date. The tools include pebble and cobble cores, sharp-edged flakes, and polyhedral cobbles.
Particularly exciting about the new site is the stratified layers also record changes in the local habitats. The habitats included systems of rivers and lakes, fern meadows, woodlands, palm groves, dry steppes, and evidence of natural burning. Fossils of wild cattle, pigs, hippos, panthers, lions, hyenas, primates, reptiles, and birds were also uncovered in the layers. From the combined evidence, researchers could re-create how early humans adapted when the landscape changed due to periodic volcanic eruptions nearby, and longer-term shifts in climate. Humans moved in and out of the area in response to the changes in the local habitat. Overall the evidence shows early humans were able to adapt when the environment shifted around them.
So far, the new site has not yet yielded any fossils of the early humans who occupied the newly uncovered site and made the stone tools, though their fossils have been found at another site less than half a mile away.
