July 17, 1959

Paranthropus boisei

Mary Leakey discovers the OH 5 hominin skull at Olduvai Gorge

Mary Leakey was walking her Dalmatians when black fossil teeth caught her eye on the slope. Louis was back at camp, ill, and missed the find entirely.

17 July 1959, the FLK locality

On 17 July 1959, Mary Leakey walked into Olduvai Gorge with her Dalmatians and noticed fossilized black teeth exposed on a rocky slope at the FLK locality.

Louis Leakey did not make the discovery with her. He felt ill that morning and remained at camp while she went into the field.

The find was catalogued as Olduvai Hominin 5. The curatorial record names Mary D. Leakey as its finder and describes it as a holotype and an almost complete cranium; documented recovery ran from 17 July to 6 August.

Not the species in the listing

The fossil was initially named Zinjanthropus boisei — the species name honouring Charles Boise, the expedition's financial supporter — and is now generally classified as Paranthropus boisei.

It is not Australopithecus afarensis. Nor was it the first Australopithecus skull found: the Taung Child, Australopithecus africanus, was recovered in South Africa in 1924 and described in Nature in 1925.

From slope to Nature in a month

Louis Leakey's formal description, "A New Fossil Skull from Olduvai," appeared in Nature on 15 August 1959, several weeks after Mary's discovery.

The Leakey Foundation puts the specimen's age at about 1.8 million years. The press nickname "Nutcracker Man" reflects its enormous chewing apparatus.

Sources

Researched 23 Aug 2026 7 sources 2 audit passes

How this was checked

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What the sources leave uncertain

The discovery date and Mary’s role are well documented. The genus assignment has changed: Zinjanthropus boisei was reassigned to Paranthropus boisei in 1960, while some taxonomic treatments have used Australopithecus boisei. It is not A. afarensis.
Olduvai was in the British-administered territory of Tanganyika in 1959; describing the location as present-day Tanzania is geographically correct but uses the later national name.