Homo habilis skull. This specimen is a relatively complete skull named KNM-ER 1813. It was found in Koobi Fora, Kenya in 1973 and is estimated to be 1.9 million years old. H. habilis is thought to have lived approximiately 2-1.6 million years ago, and had a brain size just less than half that of modern humans. The name Homo habilis means 'handy man', adopted because the species used primitive stone tools.