San Diego Museum of Man - Footsteps Through Time

Timestone 7
2.5 million years ago
Australopithecus aethiopicus

This species is an example of diversity in hominid evolution. This hominid line seems to have no relationship to our genus Homo, but represents one of several hominid species living around 2.5 million years ago.

The Black Skull, so named because minerals in the soil stained the fossil, showed the small brain case typical of australopithecines. The sagittal crest (bony ridge at the top of the skull) was an anchor for large muscles, which supported huge jaws and teeth. Scientists believe these East African hominids were the ancestors of Australopithecus boisei, which was widespread for over a million years before becoming extinct.

Cast of fossil skull
Australopithecus aethiopicus-the Black Skull
Found near Lake Turkana, in Africa, in 1985 by Richard Leakey, and reconstructed by Alan C. Walker
Age: 2.5 million years

"Black Skull" Reconstruction
Artist: William Munns

This early robust hominid shows the extreme features of a skull and jaw designed to chew tough foods. From the shape of the skull, we know this hominid had a broad, flat face.