Overview:

Paranthropus aethiopicus is still much of a mystery to paleoanthropologists, as very few remains of this species have been found. The discovery of the 2.5 million year old ’Black Skull’ in 1985 helped define this species as the earliest known robust australopithecine. P. aethiopicus has a strongly protruding face, large megadont teeth, a powerful jaw, and a well-developed sagittal crest on top of skull, indicating huge chewing muscles, with a strong emphasis on the muscles that connected toward the back of the crest and created strong chewing forces on the front teeth.

History of Discovery:

Paranthropus aethiopicus was originally proposed in 1967 by a team of French paleontologists to describe a toothless partial mandible (Omo 18) that was thought to differ enough from the mandibles of the early human species known at that time. This naming of a new species was generally dismissed; many paleoanthropologists thought it premature to name a new species on the basis of a single incomplete mandible. In 1985, when Alan Walker and Richard Leakey discovered the famous "Black Skull" west of Lake Turkana in Kenya, the classification reemerged. With its mixture of derived and primitive traits, KNM-WT 17000 validated, in the eyes of many scientists, the recognition of a new "robust" australopithecine species dating to at least 2.5 million years ago in eastern Africa.

How They Survived:

The shape and large size of the teeth indicate a largely vegetarian diet.

Evolutionary Tree Information:

Many features of the skull are quite similar to Australopithecus afarensis, and P. aethiopicus may be a descendent of this species. It is most likely the ancestor of the robust australopithecine species found later in Eastern Africa, Paranthropus boisei.

Questions:

We don’t know everything about our early ancestors—but we keep learning more! Paleoanthropologists are constantly in the field, excavating new areas with groundbreaking technology, and continually filling in some of the gaps about our understanding of human evolution.

Below are some of the still unanswered questions about P. aethiopicus that may be answered with future discoveries:

1. What kind of environments did it prefer to live in?
2. Is it actually more closely related to Au. afarensis, with which it shares many features, or the other “robust” australopithecines like P. boisei, which many scientists think is a direct descendant of P. aethiopicus?
3. How big were this species (body size)?
4. Did it exhibit body size sexual dimorphism, like most other australopithecines from this time period?

References:

First paper:

Arambourg, C., Coppens, Y., 1968. Sur la decouverte dans le Pleistocene inferieur de la valle de l'Omo (Ethiopie) d'une mandibule d'Australopithecien. Comptes Rendus des seances de l'Academie des Sciences 265, 589-590.

Other recommended reading:

Walker, A.C., Leakey, R.E., Harris, J.M., Brown, F.H., 1986. 2.5-Myr Australopithecus boisei from west of Lake Turkana, Kenya.  Nature 322, 517-522.