A three million-year-old fossil and hundreds of stone implements were discovered during an archaeological dig in Kenya near Lake Victoria. Some of the first direct evidence that early hominins used stone tools to feast on huge animals may be found in these blades, which were discovered alongside teeth from our ancestors and the slaughtered bones of ancient species resembling hippopotamuses. They were the subject of a study that was just published in Science

It has been difficult to research tool-making among our earliest ancestors due to gaps in the archaeological record. At least 3.3 million years ago, hominins—the group of primates that includes Homo sapiens and our fossil relatives—began utilizing tools for the first time. How do we know this? Because, previous stone tools from a different site in northern Kenya have established this. However, it takes another 700,000 years for the next known collection of stone tools, known as Oldowan tools, to appear in the archaeological record. Eventually, this new technology expanded throughout Africa and into Asia. But the lack of artifacts from the two early sites makes it difficult to learn how tools were manufactured and used during this nearly one million year period.

This new Kenyan site is currently providing some new insights. The story of how these new tools started initially after a worker at an excavation close to Lake Victoria in the early 2000s informed researchers that he had spotted stone tools and animal fossils emerging from the ground close to his home. 2015 saw the beginning of excavation work at the new location. The team has discovered 330 artifacts over the course of multiple field seasons, including 42 Oldowan stone tools dispersed around the skeletal remains of an extinct hippo.

A few of the hippo bones, along with other animal bones found at the site, showed evidence of having been chopped and scraped by stone tools. The related artifacts may be the oldest cache of Oldowan tools ever discovered because dating techniques put the remnants' age between 2.6 million and 3 million years. It also advances by at least 600,000 years the known beginning of human butchery of huge animals.

Some of the instruments, according to microanalysis, were likely used to pound plant material, possibly tough roots or tubers. These results imply that access to scarce foods required the use of stone tools. What early hominins could rip apart with their hands and teeth would have been their only restriction. They could manipulate food without using teeth and mouths thanks to stone tools.

Who actually created these tools, then?

Well, good question — not all of the remnants discovered at the site were made of stone tools and petrified animal bones. In fact, a tooth from the Paranthropus genus, an old relative of humans, was also discovered by the researchers. Its discovery among the hippo carcasses, coupled with another Paranthropus tooth also discovered there, supports the likelihood that Paranthropus members, rather than modern humans of the genus Homo, may have butchered the animals using some of the stone tools at the site.

Given that the first known tools existed before Homo sapiens, it is not surprising that other human lineages may have created tools. Moreover, the species has already been linked to Oldowan artifacts. Louis and Mary Leakey found the unusual tools and the first fossilized remains of Paranthropus boisei in Tanzania's Oldovai Gorge, years apart from one another.

However, following considerable debate, the tools were later credited to an early member of our genus known as Homo habilis. When Homo habilis material culture was discovered in the 1960s, Paranthropus tool making was put to one side. Around 2.8 million years ago, the first fossil of Homo habilis, who is considered to be the first prehistoric human to use tools, was discovered in Ethiopia.