Olduvai Gorge in brief
Olduvai Gorge cuts about 48 kilometres through the dry Serengeti plain in northern Tanzania, up to about 90 metres deep. The walls expose layers of lake sediments and volcanic ash laid down over about two million years, in the sequence called Beds I to IV and the younger beds above them. Fossil animals, stone tools and early human bones are found in the layers, and the volcanic ash can be dated, so the whole sequence has a time scale.
The name comes from the Maasai word oldupai, the wild sisal plant that grows there. The common spelling “Olduvai” began as a mistake by a German visitor in the early 1900s.
Discovery
In 1911 a German butterfly collector, Wilhelm Kattwinkel, chased a butterfly into the gorge and stumbled on fossil bones. His finds led a German expedition under the volcanologist Hans Reck to excavate there in 1913. Louis Leakey visited with Reck in 1931 and believed that early humans could be found. He and his wife Mary Leakey returned many times, for almost thirty years, before they made their first great discovery.
Zinj and the first tools
On 17 July 1959 Mary Leakey found the skull of Paranthropus boisei, catalogued OH 5 and nicknamed “Zinj”, at a site called FLK. It was about 1.8 million years old, much older than expected, and it made the Leakeys famous. It was found with stone tools and animal bones, and Louis Leakey first took it as the toolmaker.
In the following years the team found another, more lightly built human relative in the same layers, and named it Homo habilis, “handy man”, in 1964, since it appeared more likely to have made the tools. The fossils included a child’s skull and hand bones found by Jonathan Leakey in 1960.
Early stone tools at Olduvai, simple choppers and sharp flakes, are named Oldowan after the gorge. Mary Leakey’s careful work on the old living floors in Bed I, such as the one around Zinj, gave the first detailed picture of what early people did there, including breaking up animal bones to get at the marrow.
Later finds
- OH 9 (Chellean Man). A Homo erectus skull, about 1.4 million years old, found in 1960. It is one of the largest.
- OH 24 (“Twiggy”). A flattened habilis skull from about 1.8 million years ago, found in 1968.
- OH 62. A fragmentary skeleton of habilis found in 1986, which showed it had long arms for its leg length, like an australopith, in a surprise to those who expected a more modern body.
- Handaxes. From Bed II onward, about 1.7 million years ago, shaped handaxes of the Acheulean type appear.
Why Olduvai matters
Olduvai gave a sequence in which species, tools and landscapes could be followed through almost two million years in one place. Potassium-argon dating of its volcanic layers, from 1959, was a turning point in showing that human history stretched back millions of years. The site is still being excavated by international teams, and finds of new fossils, tools and traces of the environment continue.
Visiting
The gorge lies in the Ngorongoro Conservation Area, a World Heritage Site, between the Serengeti and the Ngorongoro Crater and about 45 km from Laetoli. The Olduvai Gorge Museum, on the rim near the Leakeys’ old camp, displays casts, tools and exhibits, and there are guided walks to viewpoints. Most visitors go on safari tours.
Sources
- Leakey, L. S. B. (1959). A new fossil skull from Olduvai. Nature 184: 491 to 493.
- Leakey, L. S. B., Tobias, P. V. and Napier, J. R. (1964). A new species of the genus Homo from Olduvai Gorge. Nature 202: 7 to 9.
- Leakey, M. D. (1971). Olduvai Gorge, Volume 3: Excavations in Beds I and II, 1960 to 1963. Cambridge University Press.
- UNESCO World Heritage Centre. Ngorongoro Conservation Area.