A nearly complete 1.6-million-year-old skeleton, found near Lake Turkana, Kenya, belonged to an eight-year-old boy. Nicknamed "Turkana Boy," the fossil is more than five feet tall and much more fully developed than a modern eight-year-old. Yet analysis of the teeth and bones indicates the boy was still growing and probably would have reached six feet as an adult. Turkana Boy is a member of the species Homo ergaster, the first early human with long legs, short arms and a tall stature--body proportions essentially like our own.
Tall and Lanky
When this fossil was found in 1984, the only other reasonably intact ancient hominid skeleton known was Lucy. But Turkana Boy is much more complete. This fossil has taught scientists a great deal about the body proportions of the species Homo ergaster. While Lucy was quite small and probably still lived in the trees part of the time, Turkana Boy and his kind were tall and lanky--and completely at home striding out on the open savanna.
Examine the Evidence: Teeth and Joints
Experts rely on two main physical features to estimate age: teeth and joints. Look for the evidence showing Turkana Boy was only about eight when he died.
- Teeth: Turkana Boy still had some milk, or "baby," teeth in his upper jaw, and fewer than half of his permanent teeth had formed--signs that he was under 10.
- Joints: As mammals mature, the spaces between the joint surface and the rest of the bone slowly close, or fuse. Many of Turkana Boy's joints had not yet fused.
Hominids of Lake Turkana
Researchers have found a wealth of hominid remains in Africa's Rift Valley, a huge geologic structure that runs from Ethiopia and Eritrea south to Malawi and beyond. Lakes and rivers have long filled many of the basins within the Rift, and the surrounding areas were once home to early hominids. Many important discovery sites are near Lake Turkana, which lies mainly in northwestern Kenya. A wide variety of hominids have been found there--including some early members of our own genus, Homo, from almost two million years ago.
Lake Turkana, Kenya
Abundant fossils of extinct animals have been found around Lake Turkana, located on the border of Kenya and Ethiopia. Some two million years ago, water levels were higher than they are today, and various hominid species flourished nearby.