Skip to Content

NEW ON VIEW: Nariokotome Boy


KNM-WT 15000
Homo erectus (or) Homo ergaster 
In 1984 the almost complete fossilized skeleton of an 11 or 12 year boy was discovered by Kamoya Kimeau, a member of one of Richard Leakey’s research teams, at the site of Nariokotome, western Lake Turkana, Kenya.  It has received the catalog number KNM-WT 15000 (Kenya National Museum-West Turkana, item 15 000). This individual has become known as either Nariokotome Boy, or more commonly Turkana Boy, and is the most complete skeleton of early genus Homo that has been discovered to date, being missing only the fossilized bones of the hands and feet.  Nariokotome Boy has been dated to ~1.6 million years ago based on the ages of the volcanic layers sandwiching the lake sediments within which the fossils were found.  Estimates by different scientists place him as somewhere between 8 and 13 years of age when he died, depending on whether early members of genus Homo matured and developed at the same rates or faster than modern humans, and whether one is looking at dentition or other parts of the skeleton. 
Nariokatome Boy
Nariokotome Boy’s preserved skeleton consists of 108 bones.  Few skeletons of this age have so- called postcranial skeletal parts – parts of the abdomen and limbs.  Based on his long bone measurements he stood about 1.5 meters or 5 feet 3 inches tall when he died, and could have exceeded 1.85 m or 6 feet 1 inch if he had achieved adulthood.  He weighed about 68 kg or 150 pounds when he died, although it is difficult to estimate what his adult weight might have been.  Physically, Nariokotome Boy had narrow hips, and somewhat longer arms than modern H. sapiens, and he was relatively tall.  Some scientists believe this long thin body type would have helped dissipate heat by increasing overall body area, consistent with the Bergmann/Allen Rule for tropical adaptation.  While the scientific consensus is that Nariokotome Boy is a member of genus Homo, he nonetheless had cranial and facial features quite different than those of modern populations.  He had almost no chin, very large brow ridges above the eyes, and a low sloping forehead characteristic of early genus Homo.  His cranial capacity of 880 cc, and an estimated adult capacity of about 910 ccs, is near the lowest end of that for modern humans.  It is arguable whether he had the capacity for modern speech.    
While specialists in the origins of modern humanity may debate the specifics of Nariokotome Boy’s position in human evolution, some preferring the taxon Homo erectus, others preferring Homo ergaster, they all agree that he is a member of our genus, the genus Homo, and not an Australopithecene like the famous and much more apelike Lucy fossil from Ethiopia which is classified as A. afarensis. 
Pictured: MSU Museum team prepares Nariokotome Boy to be articulated and mounted for exhibit in the West Gallery and the "Evolution in Action" exhibit.