Australopithecus anamensis -- KNM-KP 29285

Dublin Core


Australopithecus anamensis -- KNM-KP 29285


This partial tibia, which dates to about 4.1 million years ago, was found at the Kanapoi site in Kenya.

Fossil Item Type Metadata


A paleoanthropological research team headed by Meave Leakey

Specimen Name/Nickname

KNM-KP 29285

Location (Country)


Site (Name)


Discovery Date


Specimen/Species Time Range

about 4.1 million years ago

Dating Method

40Ar/39Ar dating of the volcanic ash layer in which it was found

Specimen Data (Morphology)

This specimen, which consists of the proximal and distal ends of a right tibia, provides the earliest evidence for bipedalism in Australopithecus anamensis. The proximal condyles, which articulate with the distal end of the femur, are concaved like the condyles seen in anatomically modern Homo sapiens. Additionally, similar to modern humans, the proximal tibia is wider near the knee joint to allow the deposit of extra spongy bone, which acts as a shock absorber during bipedal locomotion. This extra deposit of spongy bone can also be seen in the medial malleolus, which articulates with the ankle.

Overall, the partial tiba is more human-like than it is ape-like. The fact that the shock-absorbing mechanisms in Au. anamensis so closely mirror the same mechanisms seen in modern humans is what led Leakey, Kimeu, and other paloeanthropologists to believe that this species was a habitual biped. 


KNM-KP 29285
Date Added
April 7, 2017
Item Type
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“Australopithecus anamensis -- KNM-KP 29285,” Hominid Fossil Repository, accessed May 28, 2022,