The discovery of the Stone Age feeds the mystery of who made early tools

Archaeologists in Kenya have unearthed some of the oldest stone tools ever found, but who used them is a mystery.

Scientists used to assume that our direct ancestors were the only toolmakers. But two large fossil teeth found with the tools at the Kenyan site belong to an extinct human cousin named Paranthropus, according to a study published Thursday in the Journal Science.

This adds to the evidence that our direct relatives in the Homo lineage may not have been the only tech-savvy creatures during the Stone Age, said study author Rick Potts, director of the Smithsonian’s Human Origins Program.

“Those teeth open up an amazing mystery – a real question, well, who were those early toolmakers?” said Potts.

The tools date back to around 2.9 million years ago, when early humans used them to slaughter hippos for their meat, the researchers report.

Older stone tools have been found in Kenya dating back around 3.3 million years, long before our own Homo ancestors emerged. These tools were a bit simpler and have only been found in one place so far, said Shannon McPherron, an archaeologist at Germany’s Max Planck Institute for Evolutionary Anthropology who was not involved with the study.

The latest discovery fits into a much larger tradition known as the Oldowan toolkit. The same types of tools appear across Africa and beyond for more than a million years of prehistory, Potts said, showing that they really took hold among early humans.

They held a rock in one hand and hit it with another rock, breaking off thin, razor-sharp flakes, explained Kathy Schick, an anthropologist at the Stone Age Institute in Indiana, who was not involved with the research.

The rocks and flakes allowed early humans to cut and crush a variety of materials, said lead author Thomas Plummer, an anthropologist at Queens College, City University of New York. And the tools from Kenya – probably the oldest Oldowan tools found to date – suggest this gave them an advantage in one key area: eating.

The place, known as Nyayanga, is a lush, hilly landscape on the shores of Lake Victoria. Since excavations began there in 2015, researchers have found a treasure trove of artifacts and animal bones alongside the two Paranthropus teeth.

Cut marks on several hippo bones show they were dismembered for their meat, which would have been eaten raw as hippo tartare, Plummer said. Early humans also likely used their tools to crack open antelope bones for their fatty marrow inside and to peel the outer barks of tough plant roots, the authors concluded.

“Stone tools allow them to extract a lot of resources from the environment, even at this very early stage,” Plummer said. “If you can butcher a hippopotamus, you can butcher just about anything.”

In the past, it was easy to assume that our direct ancestors were the ones who used these tools, Plummer said. But the teeth make it hard to rule out that other early humans picked up their own tools, researchers said — even extinct cousins ​​like Paranthropus, with their big teeth and small brains.

The puzzle will be difficult to solve.

Finally, we can’t say for sure if Paranthropus used those tools or just happened to die in the same spot, Schick said, “When we find hominin fossils with stone tools, one always has to ask, is that the dinner or the diner?”

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