Lomekwi stone tools

Stone flakes and cores found at Lomekwi in Kenya are about 3.3 million years old. They pre-date the first members of our own genus.

Context

The Lomekwi 3 site beside Lake Turkana was found in 2011, when a research team took a wrong turn and noticed stone artefacts on the surface. Excavation produced dozens of flakes, cores and anvils, and the results were published in Nature in 2015. The tools are larger and cruder than the later Oldowan tools from about 2.6 million years ago.

The age comes from the layers of rock around the artefacts. Researchers used the magnetic polarity of the sediments and the chemistry of volcanic ash layers to place the finds at about 3.3 million years ago. Some scholars have questioned whether all the pieces are deliberate tools, so the age is shown as an estimate.

Nobody knows who made them. The earliest known members of our genus, Homo, are currently dated to roughly 2.8 million years ago, so the toolmaker was probably an earlier hominin such as Kenyanthropus or an australopithecine. Other claims, such as cut-marked bones from Dikika in Ethiopia at about 3.4 million years, are debated.Because the site was found on the surface of eroded ground, researchers also had to show that the tools really came from the dated layer and had not simply washed down from elsewhere, a point that is still discussed.