Turkana Boy - Morphology

Morphology

The specimen comprises 108 bones, making it the most complete early human skeleton discovered. The skeleton is about 1.60 m (5 ft 3 in) tall. In adulthood, Turkana Boy might have reached 1.85 m (6 ft 1 in) tall and massed 68 kg (150 lb).

The pelvis is narrower than in Homo sapiens, which might indicate more efficient running, whether to run down small game or to avoid predators. Turkana Boy's people might have hunted more than did Homo habilis. The Boy was relatively tall, which would have increased his surface area and helped him to dump heat.

Body hair may also have been thinner to hasten cooling. In The Evolution of Bipedality and Loss of Body hair in Hominids, P. E. Wheeler suggests that body hair was lost in the shift towards savanna living. In equatorial Africa, modern humans evolved this trait an estimated one million years ago. However, more recent research indicates that Ardipithecus ramidus developed bipedality for moving through trees about 4.4 million years ago.

The overall KNM-WT 15000 skeleton still had features (such as a low sloping forehead, strong brow ridges, and the absence of a chin) not seen in H. sapiens. The arms were slightly longer. Turkana Boy had a projecting nose rather than the open flat nose seen in apes.