Homo habilis skull bones. These parietal (cranial) bones and mandible (jaw bone) were found in Olduvai Gorge, Tanzania in 1960. The specimen is called OH 7 and is estimated to be 1.75 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.