Discovered near Lake Turkana, Africa, in 1985 by Richard Leakey, and reconstructed by Alan Walker, the Black Skull (KNM-WT 17000) is the most diagnostic specimen of Australopithecus aethiopicus ever found. It is referred to as the Black Skull because the manganese in the soil turned the bones black during mineralization. It has been dated to 2.5 million years ago.

The Black Skull is really fascinating because it shares early Australopithecus afarensis traits with later Australopithecus robustus traits, making it an unusual and important find. Because of its distinct morphology, the Black Skull is considered to be the earliest robust species to date. Like other australopithecines, A. aethiopicus may have had hominid characteristics such as the ability to walk bipedally.