Oldowan Tools: The First Stone Tool Industry of Olduvai

The Oldowan is the oldest widespread stone tool industry, made in Africa from about 2.6 million years ago and named after Olduvai Gorge in Tanzania. Its makers struck sharp flakes from river cobbles with hammerstones, producing simple but effective cutting tools. For more than a million years the Oldowan was the basic technology of early humans, and it was the first to spread beyond Africa.

The name and the Leakeys

Olduvai Gorge (officially Oldupai) is a steep-sided ravine about 48 kilometres long on the edge of the Serengeti Plain. Its layered sediments, divided by geologists into Beds I to IV, record nearly two million years of lake and river deposits, volcanic ash and buried campsites.

Louis Leakey first worked at Olduvai in 1931 and soon recognised the abundance of crude stone tools in its lower beds. He used the term Oldowan for this industry in the 1930s. Over the following decades he and his wife, the archaeologist Mary Leakey, made the gorge one of the most important sites in human evolution. On 17 July 1959 Mary Leakey found the skull known as Zinjanthropus (now Paranthropus boisei) at a site called FLK, close to Oldowan tools and broken animal bones.

Mary Leakey’s excavations in Beds I and II, published in 1971, became the classic description of the industry. She sorted the tools into types such as choppers, polyhedrons, discoids, scrapers and spheroids, and she described a later phase she called the Developed Oldowan. In 1969 the archaeologist Grahame Clark grouped such simple core-and-flake industries as “Mode 1” in his global scheme, a label still used today.

Earliest dates: Gona and beyond

Olduvai is not where the Oldowan began. The oldest Oldowan tools at the gorge, in Bed I, are about 1.9 to 1.8 million years old. Older examples have since been found farther north.

In 1997 a team led by Sileshi Semaw reported stone tools from Gona in the Afar region of Ethiopia dated to between about 2.6 and 2.5 million years ago. Further finds at Ledi-Geraru, also in the Afar, were dated in 2019 to about 2.58 million years ago. In 2023 researchers described Oldowan tools from Nyayanga in western Kenya with an age between about 3.0 and 2.6 million years. Even older and cruder artefacts from Lomekwi 3 in Kenya, about 3.3 million years old, are usually treated as a separate, earlier technology.

How the tools were made

The basic Oldowan method was simple but required skill. A knapper held a cobble of lava, quartz or chert in one hand and struck it near the edge with a hammerstone held in the other. A well-aimed blow at the right angle detached a sharp flake, leaving a scar on the core. Repeating the process produced more flakes and gave the core a jagged cutting edge.

Experiments have shown how much control this needs. In the 1990s the archaeologists Nicholas Toth and Kathy Schick, working with the psychologist Sue Savage-Rumbaugh, taught a bonobo named Kanzi to make flakes. Kanzi learned to produce usable cutting edges but never matched the consistent, well-angled flaking seen at early Oldowan sites, which suggests that the early toolmakers understood stone fracture better than any living ape.

Many archaeologists now think that the flakes, rather than the heavier cores, were the main tools. The “choppers” of older classifications may often be simply the cores left behind after flakes were removed.

Choosing and carrying stone

Oldowan toolmakers were not simply picking up whatever rock lay at hand. At several sites the tools are made of stone that came from sources some distance away. At Kanjera South, for example, part of the raw material was carried from outcrops more than ten kilometres from the site, and the toolmakers favoured hard, fine-grained rocks that keep a sharp edge.

At Olduvai, knappers used both lava cobbles from nearby streams and quartzite from a rocky hill known as Naibor Soit, a few kilometres from the main sites. Choosing suitable stone and carrying it across the landscape implies some planning ahead, a step beyond the opportunistic tool use seen in living apes.

Myths and facts

A common image shows Oldowan tools as crude rocks that barely differ from natural stones. In fact, archaeologists identify them by clear features: repeated flake scars, struck platforms and bulbs of percussion that natural breakage rarely produces in the same combination. Another myth is that the Oldowan was static. Studies of the later Olduvai sites show gradual changes, including more heavily worked cores and more spheroids, before the Acheulean appeared.

What the tools were used for

The clearest evidence of use comes from animal bones. Many bones from Oldowan sites carry cut marks from slicing meat and percussion marks from hammerstones used to crack bones for marrow. At FLK Zinj at Olduvai, dated to about 1.84 million years ago, thousands of bones and stone artefacts lie together on an ancient land surface. Archaeologists still debate whether early humans there were hunting, or arriving early or late at carcasses killed by large carnivores.

Microscopic wear on some flakes from Kanjera South in Kenya, about 2 million years old, shows that they were also used to cut grasses and other plants and to work wood. Oldowan tools allowed early humans to get at energy-rich foods such as meat, marrow and underground plant parts, a change many researchers link to the growth of the brain in the genus Homo.

Who made them

The traditional answer is Homo habilis, named at Olduvai in 1964 partly because its fossils were found near the tools. Early Homo erectus also used Oldowan technology. However, the oldest tools are older than the earliest known Homo fossils, and robust hominins such as Paranthropus lived alongside Homo for hundreds of thousands of years. At Nyayanga, the only hominin remains found with the tools were Paranthropus teeth. Most researchers therefore accept that more than one kind of hominin may have made Oldowan tools.

Spread out of Africa

Oldowan technology spread widely. Tools at Ain Boucherit in Algeria have been dated to about 2.4 million years ago. At Dmanisi in Georgia, the earliest known hominin fossils outside Africa, about 1.8 million years old, were found with Oldowan-type tools. Stone tools from Shangchen in China, reported in 2018, are dated to about 2.1 million years ago.

From about 1.76 million years ago a new technology, the Acheulean, with its large shaped hand axes, appeared in East Africa. The Oldowan did not vanish at once, however: simple core-and-flake industries continued alongside or instead of hand axes in many regions for a very long time.

Timeline

• c. 2.6 million years ago: Oldowan tools are made at Gona and Ledi-Geraru, Ethiopia.
• c. 2.4 million years ago: Oldowan tools are made at Ain Boucherit, Algeria.
• c. 1.84 million years ago: Hominins butcher animals at FLK Zinj, Olduvai Gorge.
• c. 1.8 million years ago: Hominins with Oldowan-type tools reach Dmanisi, Georgia.
• c. 1.76 million years ago: The first Acheulean hand axes appear in East Africa.
• 1931: Louis Leakey begins work at Olduvai Gorge.
• 17 July 1959: Mary Leakey finds the Zinjanthropus skull at FLK, Olduvai.
• 1971: Mary Leakey publishes her classic study of the Olduvai Bed I and II tools.
• 1997: Sileshi Semaw’s team publishes the 2.5-million-year-old Gona tools.

Why it matters

The Oldowan marks the point at which stone tools became a regular part of hominin life. Its sharp flakes opened up new foods and new ways of living on the African savanna, and its spread to North Africa, the Caucasus and China shows how far early humans travelled with this simple kit. Almost every later stone technology, from hand axes to fine blades, grew out of the basic skill first seen in the Oldowan.