Australopithecus aethiopicus or Paranthropous aethiopicus

aethiopicus existed between 2.6 and 2.3 million years ago. This species is known from one major specimen, the Black Skull discovered by Alan Walker in 1985, and a few other minor specimens, which may belong to the same species.

An interesting thing about this species is that it had features which seem to be mid-way between A. afarensis and the other robust types (boisei and robustus). The features are listed below:

1. Cranium was still very small and chimp-like.It may be an ancestor of robustus and boisei.
2. The brain size is very small, at 410 cc, and parts of the skull, particularly the hind portions, are very primitive, most resembling afarensis. The massiveness of the face, jaws and single tooth found, and the largest sagittal crest in any known hominid, are more reminiscent of boisei.

Fossils found:

KNM-WT 17000, "The Black Skull", Australopithecus aethiopicus .

It was discovered by Alan Walker in 1985 near West Turkana in Kenya. Its estimated age is 2.5 million years. This find is an intact, almost complete cranium. The brain size is very small for a hominid, about 410 cc, and the skull has a puzzling mixture of primitive and advanced features.