Scientists have established who made the first stone tools – 2.9 million years ago

Excavations at Nyayang, July 2016. Photo: J.S. Oliver, Khoma Peninsula Paleoanthropological Project.. (CREDIT: Smithsonian Institution)

Along the shores of African Lake Victoria in Kenya, approximately 2.9 million years ago, ancient human ancestors used some of the most ancient stone tools ever found to butcher hippos and grind up plant material, according to a new study by scientists at the Smithsonian National Museum of Natural History. . and Queens College, CUNY, as well as the National Museums of Kenya, Liverpool John Moores University and the Cleveland Museum of Natural History.

The study, published in the journal Science, presents what are probably the oldest examples of the hugely important Stone Age innovation known to scientists as the Olduvian toolkit, as well as the oldest evidence that hominids ate very large animals.

While several pieces of evidence indicate the artifacts are probably around 2.9 million years old, the artifacts could be more conservatively dated between 2.6 million and 3 million years old, said study lead author Thomas Plummer of Queens College, a postdoctoral fellow at the science team. . Smithsonian program Human Origins.

Excavations at a site called Nyayanga, located on the Homa Peninsula in western Kenya, have also unearthed a pair of massive molars belonging to a close evolutionary relative of the human paranthropus.

Related news

The teeth are the oldest Paranthropus fossils ever found, and their presence in a site filled with stone tools raises intriguing questions about which human ancestors made these tools, said Rick Potts, senior author of the study and Peter Buck of National Museum of Natural History. Department of human origin.

“There has long been an assumption among researchers that only the genus Homo, to which humans belong, is capable of making stone tools,” Potts said. “But the discovery of the Paranthropus next to these stone tools opens up an exciting detective story.”

Whichever lineage of hominid is responsible for these tools, they were found more than 800 miles from the earliest known examples of Oldowan stone tools, 2.6 million years old tools found at Lady Geraru, Ethiopia. This greatly expands the area associated with the earliest origins of Aldovan technology. In addition, stone tools from excavations in Ethiopia could not be tied to any particular function or use, leading to speculation as to what the earliest use of the Oldowan toolkit might have been.

By analyzing the wear marks of stone tools and animal bones found in Nyayang, Kenya, the team behind this latest discovery shows that these stone tools were used by early human ancestors to process a wide range of materials and foods, including plants, meat, and even bone. brain.

The Oldowan toolbox includes three types of stone tools: chippers, cannonballs, and flakes. Hammers can be used to strike other stones to create tools, or to grind other materials. The kernels are usually angular or oval in shape, and when struck at an angle with a hammer, the kernel breaks off into a piece or flake that can be used as a cutting or scraping edge or further cleaned with a hammer.

“With these tools, you can crush better than an elephant’s molars and cut better than a lion’s fangs,” said Potts. “Olduvian technology was like the sudden evolution of a whole new set of teeth outside of your body, and it introduced our ancestors to a new variety of foods on the African savannah.”

Potts and Plummer first came to the Homa peninsula in Kenya from reports of large numbers of fossilized baboon monkeys called Theropithecus oswaldi, which are often found alongside evidence of human ancestors. After many visits to the peninsula, a local resident named Peter Onyango, who was working with the team, suggested that they check out fossils and stone tools eroded away at a nearby site, which was eventually named Nyayanga after a nearby beach.

Beginning in 2015, a series of excavations at Nyayang have unearthed 330 artifacts, 1,776 animal bones, and two hominin molars identified as belonging to Paranthropus. The artifacts, according to Plummer, were clearly part of the technological breakthrough of the Stone Age, which was the set of tools of Oldovan.

Compared to the only other stone tools known to have preceded them—a 3.3-million-year-old set of artifacts found at a site called Lomekwi 3, west of Lake Turkana in Kenya—the Oldowan tools were vastly improved. Olduvian tools were systematically produced and often shaped using the so-called “freehand strike”, which means that the core was held in one hand and then struck with a jackhammer wielded by the opposite hand at the right angle to form a flake technique. which requires considerable dexterity and skill.

In contrast, most artifacts from Lomekwi 3 were created using large, immovable stones as an anvil, with the tool maker either hitting the cannonball against a flat anvil stone to create flakes, or placing the cannonball on the anvil and hitting it with a hammer. . These more rudimentary methods of manufacture resulted in larger, cruder, and more messy-looking instruments.

Over time, the Oldowan toolkit spread throughout Africa and even as far as present-day Georgia and China, and it was not substantially replaced or altered until the appearance of Acheulean hand axes about 1.7 million years ago.

As part of their study, the researchers conducted a microscopic analysis of the wear patterns of stone tools to determine how they were used, and examined any bones that showed cut marks or other types of damage that could have been received from stone tools.

The site featured at least three hippos. Two of these incomplete skeletons included bones with traces of cutting. The team found a deep cut on a fragment of the rib of one hippo and a series of four short parallel cuts on the lower leg of another. Plummer said they also found antelope bones, which showed evidence that hominins cut flesh with rock flakes or were crushed with hammers to extract marrow.

Analysis of the wear marks of 30 stone tools found in this area showed that they were used to cut, scrape and prick both animals and plants. Since fire would not be used by hominins for another 2 million years or so, these stone tool makers ate everything raw, perhaps grinding the meat into something like hippo tartare to make it easier to chew.

Using a combination of dating methods, including the rate of decay of radioactive elements, the reversal of the Earth’s magnetic field, and the presence of certain fossil animals well dated in the fossil record, the research team was able to date the items recovered from Nyayanga. between 2.58 and 3 million years old.

“This is one of the oldest, if not the oldest, examples of Oldowan technology,” Plummer said. “This shows that tooling was more widespread earlier than people thought, and that it was used to process a wide variety of plant and animal tissues. We don’t know for sure what the adaptive value was, but the variety of uses suggests it was important to these hominins.”

The discovery of the teeth of a musculoskeletal paranthropus next to these stone tools raises the question of whether it was this line, and not the genus Homo, that might have been the architect of the earliest Oldowan stone tools, or perhaps even several lines produced these tools. instruments around the same time.

The excavations underlying this study provide insight into the world in which human ancestors lived and help illustrate how stone-working technology allowed these early hominins to adapt to different environments and eventually give rise to the human species.

“East Africa was not a stable ancestral home for our species,” Potts said. “It was more of a seething cauldron of environmental change, with rainstorms and droughts and a varied, ever-changing food menu. Olduvian stone tools could cut through and split it all and help early toolmakers adapt to new places and new opportunities, whether it be a dead hippopotamus or a starchy root.”

This research was funded by the Smithsonian Institution, the Leakey Foundation, the National Science Foundation, the Wenner-Gren Foundation, the City University of New York, the Donner Foundation, and the Peter Buck Foundation for Human Origins Research.

For more science news, visit our New Discoveries section at The bright side of the news.

Note: Material provided above by the Smithsonian Institution. Content can be edited for style and length.

Do you like such pleasant stories? Get Brighter Side of News Newsletter.