Ancient hominids made long road trips to collect stone for tools

Starting at least 2.6 million years ago, East African toolmakers became tech-savvy road warriors.

Those hominids, perhaps early members of the Homo genus or a dead-end lineage dubbed Paranthropus, traveled up to 13 kilometers from a lakeshore site to obtain and bring back rocks suitable for fashioning into durable stone tools. The finding pushes back the timing of hominids’ long-distance retrieval of any resource by roughly 600,000 years, the scientists report August 15 in Science Advances.

The cutting and pounding tools were excavated at Kenya’s Nyayanga site on the eastern shore of Lake Victoria and have been categorized by archaeologists as Oldowan implements. Researchers previously reported that Nyayanga’s ancient hominids used Oldowan tools to cut and pound plants and animal tissue, including that of hippos. Excavations at the Kenyan site also uncovered two large, peg-shaped Paranthropus teeth. The researchers cannot yet say whether big-jawed, small-brained Paranthropus or members of an early Homo species transported tool-suitable rock to Nyayanga.

What is clear is that “Nyayanga represents the oldest documented case of long-distance transportation of raw materials,” says archaeologist Manuel Domínguez-Rodrigo of the University of Alcalá in Madrid and Rice University in Houston, who was not involved in the study.

Until now, the earliest evidence of hominids carrying rocks for toolmaking over distances of 10 to 13 kilometers dated to about 2 million years ago at two East African sites. One of those sites is in Tanzania. The other, Kanjera South, lies about 15 kilometers northeast of Nyayanga.

In the new work, archaeologist Emma Finestone of the Cleveland Museum of Natural History and colleagues compared the geochemical signatures of 401 Nyayanga stone artifacts with those of samples taken from 11 exposed rock deposits in Kenya. Deposits’ distances from Nyayanga ranged from less than 1 kilometer to 18.6 kilometers.

Nyayanga cutting and pounding tools, including stones from which they were struck, came from high-quality deposits located about 13 kilometers away, the investigators say. Cutting tools made from relatively soft rocks near Nyayanga would have dulled quickly, Finestone says. When pounded, Nyayanga-area rock would have frequently shattered.

Long-distance rock transport by Nyayanga toolmakers challenges a view held by some researchers that early Oldowan toolmakers behaved much like chimpanzees do today, Domínguez-Rodrigo says. Researchers have observed wild chimps carrying stones used in pounding tasks over distances of slightly more than 2 kilometers, usually in a series of short treks.

In contrast, the new Nyayanga findings suggest early Oldowan toolmakers integrated a search for quality stone into extended foraging trips for edible plants and other supplies, Finestone says. “This implies an early understanding of how different resources were distributed across the landscape and an ability to link distant resources into a comprehensive foraging strategy.”

In other words, ancient road warriors learned to blaze trails far beyond the horizon.