Turkana boy

Turkana boy, or Nariokotome boy, is the nickname for a fossil skeleton found in 1984. Its official name is KNM-WT 15000.KNM-WT 15000: Kenya National Museum; West Turkana; item 15000 It is a nearly complete skeleton of a hominid who died in the early Pleistocene epoch 1.5 million years ago (mya), near present-day Lake Turkana in northwest Kenya. 

This specimen is the most complete early human skeleton ever found. It was first classified as Homo erectus; after much heated debate, it was re-classified as Homo ergaster. The shape of the pelvis shows that the specimen was a male. 

The skeleton was discovered in 1984 by Kamoya Kimeu, a member of a team led by Richard Leakey, at Nariokotome near Lake Turkana.Brown F; Harris J; Leakey R. & Walker A. 1985. Early Homo erectus skeleton from west Lake Turkana, Kenya. Nature. 316 (6031):788-92. PMID 3929141

 Characteristics 

 Height 
Scientists first thought that Turkana boy would have been 1.85 meters tall, but recently a height of 1.63 meters was proposed.Graves R.R. et al 2010. Just how strapping was KNM-WT 15000? J Hum Evol.  PMID 20846707 

 Age 
Scientists do not know exactly how old Turkana boy was when he died. Estimates say he was between 7 years six months and 15 years old. The most recent scientific review suggests he was 8 years old. 

His estimated age at death depends upon whether the maturity stage of his teeth or skeleton is used, and whether that maturity is compared to that of modern humans or chimpanzees.

 Adolescent growth 
Research showed that Turkana boy's growth differed from that of modern humans: he would have had a shorter and smaller adolescent growth spurt.

A key factor here is that while modern humans have a marked adolescent growth spurt, chimpanzees do not. While initial research assumed a modern human type of growth, more recent evidence from other fossils suggests this was less present in early Homo. This affects the estimation of both his age and his likely stature as a fully grown adult.

Morphology
The pelvis is narrower than in Homo sapiens, which might indicate more efficient running, whether to run down small game or to avoid predators. The Boy was relatively tall, which would have increased his surface area and helped him to lose heat.

Body hair was lost in the shift towards savanna living. The Boy's body hair may also been thinner to hasten cooling. In equatorial Africa, modern humans evolved this trait an estimated one million years ago.Wheeler P.E. 1984. The evolution of bipedality and loss of functional body hair in hominids. Human evolution 13, 91–98.

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

 References 

Sources

  – Good popular level presentation
  – Technical papers


Category:Hominins
Category:Fossils
Category:Prehistoric Africa
Category:Archaeological sites in Kenya