Olduvai Gorge - Tanzania

History of archaeological work at Olduvai
In 1911, a German entomologist, Professor Kattwinkel, was the first European to enter the gorge. He noticed many fossil bones, identified as an extinct three-toed horse. This inspired Professor Hans Reck to lead an expedition to Olduvai in 1913. he found a hominid skeleton, but further work was halted by World War I. some years later, Louis Leakey saw the Olduvai fossils in Berlin and was convicted that Olduvai must hold valuable clues to human origins. In 1931, Leakey organised an expedition to the Gorge with Reck, and found stone tools within a few hours of arriving at the gorge.

In further excavations, Leakey and his wife Mary found and described many stone tools and fossil animals, but found no significant hominid (“human-like”) fossils until 1959, when Mary Leakey discovered the first skull of “Zinjanthropus“. Now renamed Australopithecus boisei, this creature had a massive skull with huge teeth that suggested a diet of coarse vegetable food, and lived 1.75 million years ago.

1976 Mary Leakey discovered a fossil hominid and animal tracks at Laetoli, a site twice as ancient as anything at Olduvai. It is well worth visiting the site where “Zinj” was found, just five minutes’ drive from the visitor centre. Ask the guides for the latest discoveries!

A reconstruction of hominid history
3,500,000 years ago, our very remote ancient ancestors walked through a landscape very like that which we see today. The volcanoes were fewer but more active then, though Ngorongoro had not yet towered high above the others. On one particular day, the volcano Sadiman puffed out a lot of grey ashes, so that the local animals left crisp, clear tracks when they walked. Some of the creatures have changed little; hares were abundant, guinea-fowl scurried about, giraffes strode regally over the plain. Others are no longer with us, such as an elephant with downward-curving tusks in its lower jaw, and Hipparion, a three-toed horse.

Through this desolate grey landscape that would later be named Laetoli travelled through hominids. Shorter than ourselves (1.2 to 1.4 metres high), they may have looked more than apes than people, but they walked on two legs. A large, a medium-sized and a small individual walked together, the medium-sized one stepping in the tracks of its large companion. A day or two later, a fresh ash-fall buried the tracks, until they were excavated in 1978. We know from contemporary fossils that the footprints were made by Australopithecus afarensis, an early hominid.

It is tempting to wonder why these ape-like, small brained creatures (450cc; our own brains average 1400cc) walked upright – could they see further afield? Did they use their hands for carrying water, food, or babies? Or did they carry sticks, stones or thorn branches to fight off neighboring hominids, or predators? If they carried such weapons, did they use them in self-defense or to stela kills from hunters?

1,890,000 years ago, the volcano Olmoti erupted, and thick lava flows covered the area now occupied by Olduvai Gorge. burying any earlier remains beneath black basalt. A lake soon formed there, and became the focus of activity for a wide variety of animals. Its alkaline waters provided ideal conditions for fossilizing dead animals and plants falling in it.

The descendants of Laetoli’s upright-walkers were at Olduvai. Two different kinds of hominids left remains in the deepest level of the gorge, Australopithecus boisei and homo habilis (“handy man”).

1,500,000 years ago, earth movements and faulting caused “Lake Olduvai” to be drained. At this time Australopithecus afarensis was still presented, while homo habilis had evolved to homo erectus (“upright man”), our direct ancestors. This human had a bigger brain (900cc) and made better stone hand-axes. Only 17,000 years ago homo sapiens lived in the gorge.