Turkana Boy

Turkana Boy, also called Nariokotome Boy, is the name given to fossil KNM-WT 15000, a nearly complete skeleton of a Homo ergaster youth who lived 1.5 to 1.6 million years ago. This specimen is the most complete early hominin skeleton ever found. It was discovered in 1984 by Kamoya Kimeu on the bank of the Nariokotome River near Lake Turkana in Kenya. Estimates of the individual's age at death range from 7 to 11 years old. Although the specimen is largely considered male due to the shape of the pelvis, the sex is ultimately indeterminate due to its prepubescent age. Estimates of the age at death depend on whether the maturity stage of the teeth or skeleton is used, and whether that maturity is compared to that of Homo sapiens or to chimpanzees. A key factor is that modern humans have a marked adolescent growth spurt, whereas chimpanzees do not. Initial research assumed a modern human type of growth, but recent evidence from other fossils suggests this was less present in early Hominids. This difference affects the estimates of both the age and the likely stature of the specimen as a fully grown adult. Alan Walker and Richard Leakey in 1993 estimated the boy to have been about 11–12 years old based on known rates of bone maturity. Walker and Leakey (1993) said that dental dating often gives a younger age than a person's actual age. Christopher Dean (M. C. Dean) of University College London, in a 2009 Nova special, estimated that the Turkana Boy was 8 years old at death. The specimen comprises 108 bones, making it the most complete early human skeleton discovered. The Smithsonian estimates that he was tall and weighed when he died, and may have been close to his adulthood height. In adulthood, Turkana Boy might have reached tall and massed . The pelvis is narrower than in Homo sapiens, which is most likely for more efficient upright walking. This further indicates a fully terrestrial bipedalism, which is unlike older hominin species that show a combined feature of bipedalism and tree climbing.