The Oldowan has traditionally been associated with the species Homo habilis, as it was found at the same site as Oldowan tools in Olduvai Gorge, Tanzania in 1964. Since then, fossils of Paranthropus boisei have also been found at sites with Oldowan tools in eastern Africa, including at Olduvai Gorge. A study from October uses stone tools along with butchery marked bones to expand our understanding of earlier hominin diets and ranges, describing sites from Nyayanga, Kenya dating to around 3 million years ago containing Oldowan stone tools. This expands the range of where these tools are found at the time by over 1300 kilometers and also pushes the date for Oldowan tools back by as much as 400,000 years. These stone tools were likely used to butcher an ancient hippopotamus, as cut-marked hippo bones were found in the same layer. At Nyayanga, there are two Paranthropus molars in the same layer as the Oldowan tools and butchered hippo bones - but there are no Homo habilis fossils known from this excavation. Knowing which species made and used stone tools is difficult when there are multiple hominins on the landscape at the same time, but this study suggests that ruling Paranthropus out as a possible tool-maker is unwise.

These findings were presented in the journal Science on February 9th, 2023, by Tom Plummer and colleagues.