In 1967 Arambourg and Coppens discovered  Omo 18, the first specimen of Paranthropus aethiopicus, also known as Paraustralopithecus aethiopicus; however it's classification as a new species was initially dismissed. In 1985, when Alan Walker and Richard Leakey discovered the famous "Black Skull" (KNM-WT 17000) west of Lake Turkana in Kenya, the classification reemerged. and a new "robust" australopithecine species dating to at least 2.5 million years before present in eastern Africa, became accepted.