Stone Tools Used By Hippo-Eating Human Ancestors Are Millions Of Years Old, Researchers Say

Topline

A toolkit used by human ancestors discovered by researchers along the shores of Kenya’s Lake Victoria could be the oldest ever found, according to a study published Thursday in Science, leading researchers to question which human ancestor first developed stone-age tools.

Key Facts

The excavation site, located on the Homa Peninsula in western Kenya, produced an Oldowan toolkit—stone tools used to hit and shape other rocks or plant materials—estimated to be between 2.6 and 3 million years old, according to a group of international scientists organized by the Smithsonian.

A pair of molars belonging to the Paranthropus—an evolutionary relative of humans—was also discovered, suggesting it had created stone tools before direct human ancestors.

Rick Potts, an anthropologist with the Smithsonian who focuses on human origins, said the discovery “opens up a fascinating whodunnit” as the previously known oldest examples of Oldawan tools were estimated to be 2.6 million years old.

An analysis of wear patterns on the tools and animal bones found nearby the excavation site suggests the tools were used to process materials and foods, including plants, meat and bone marrow.

Bones of at least three hippos were also found, researchers said, with indications the tools had been used to extract bone marrow and more precisely pull away flesh.

Surprising Fact

The discovery presents the oldest evidence of human ancestors consuming larger animals, like hippos, according to lead study author Thomas Plummer.

Big Number

1.7 million. That’s how many years ago human ancestors upgraded the Oldawan toolkit, researchers said, resulting in the first-known examples of hand axes.

Key Background

Researchers say they were drawn to the Homa Peninsula in Kenya because of reports of fossilized baboon-like monkeys found in the area. After beginning a series of excavations in 2015, resulting in the discovery of 330 artifacts and 1,776 animal bones, researchers began to analyze technological breakthroughs in the stone age that resulted in the Oldowan toolkit. Previously, stone tools that had been discovered 800 miles from the Kenyan dig site were estimated to be 3.3 million years old, though they were more “haphazard,” simple and crude. The Oldowan tools were a “significant upgrade in sophistication,” researchers said, as they had been “systematically produced” and were used with techniques that require “significant dexterity and skill” in comparison to the older stone tools.

Further Reading

Stone Tools Forensics Revealed The Last Days Of Otzi The Iceman (Forbes)