The shores of Lake Victoria, in Kenya, were the place chosen by the first human ancestors to dismember hippos and crush vegetables three million years ago. Beyond being the oldest evidence of hominids consuming large animals, the find has served to reveal something much more surprising: the appearance of some of the first stone tools.
The discovery made at the Nyayanga site, located on the Homa peninsula, has been complemented by the appearance of a pair of massive molars belonging to a close relative of humans, the extinct Paranthropus. These teeth are the oldest remains of this species that have been found so far.
Both findings have led researchers, led by scientists from the Smithsonian Museum and Queens College, to reopen the debate about who made the first stone utensils and everything points to it not being humans, according to an article published in the journal Science.
“For a long time, the assumption has been that only the genus Homo, to which we and our ancestors belong, was capable of making stone tools,” said Rick Potes, lead author of the study. “But finding Paranthropus remains alongside these instruments opens up a fascinating intrigue,” he adds.
Whatever the hominin lineage responsible for these tools, what is clear is that they were found 1,300 kilometers away from the oldest known examples of Oldowan stone tools, those unearthed at Ledi-Geraru, Ethiopia, and dating from 2.6 million years ago. This greatly expands the area associated with the origins of Olduvayan technology.
Wear patterns on the stone tools and animal bones discovered at Nyayanga, the researchers show, were used by early human ancestors to process a wide range of materials and foods, including plants, meat and even bone marrow.
The Oldowan toolkit includes three types of tools: hammers, cores, and flakes. Hammers can be used to hit other rocks or to crush other materials. The kernels are often angular or oval in shape, and when struck at an angle with a firing pin, they break into flakes that can be used as a cutting, scraping, or refining edge.
“With these tools you can grind better than an elephant’s molars and cut better than a lion’s canines,” Potes said in a statement. “Olduvayan technology was like suddenly growing a new set of teeth outside your body, and it opened up a new variety of food on the African savannah for our ancestors,” he adds.
Excavations that began in 2015 have found a treasure trove of 330 artifacts, 1,776 animal bones and the two hominid molars belonging to Paranthropus. The artifacts are clearly part of the stone age technological advance that was the Oldowan toolkit.
Compared to the only other stone tools known to have preceded them, a 3.3-million-year-old set of artifacts unearthed at a site called Lomekwi 3 by Lake Turkana in Kenya, the Nyayanga tools meant a significant improvement in sophistication.
Oldowan tools were made using what is known as “freehand percussion”, meaning that the core was held in one hand and then struck with a hammer held in the opposite hand at the correct angle to produce a flake. , a technique that requires a lot of dexterity and skill.
By contrast, most of the Lomekwi 3-type artifacts, which were created using large rocks (or anvils), used more rudimentary modes of manufacturing that resulted in larger, coarser, and messier-looking tools.
Over time, the Oldowan tool set spread throughout Africa and even as far as present-day Georgia and China, and was not replaced or significantly modified until around 1.7 million years ago, when axes first appeared. by the hand of the Acheulean.
The site in Lake Victoria featured at least three individual hippos. Two of these incomplete skeletons included bones that showed signs of butchery. The team found a deep cut mark on one rib and a series of four parallel cuts on the shin of another animal. Antelope bones were also found showing evidence of hominids cutting the flesh with stone flakes or having been crushed by hammers to extract the marrow.
Because fire would not be harnessed for cooking until at least 2 million years later, these stone tool makers would have eaten everything raw, perhaps pounding the meat into something like a hippo tartare to make it easier to eat. chew.
“East Africa was not a stable space for the ancestors of our species,” Potts said. “It was more of a boiling cauldron of environmental change, with downpours and droughts and a diverse and ever-changing food menu. Oldowan stone tools could have cut and pounded it and helped early instrument makers adapt to new places and seek new opportunities, be it a hippopotamus or a starchy root,” he concludes.