Robust australopiths (Paranthropus)

Paranthropus, often called the robust australopiths, was a branch of early hominins with enormous jaws and huge, flat molars, adapted to chewing tough plant foods. The earliest species, Paranthropus aethiopicus, is known from about 2.7 million years ago, including the 'Black Skull' found at West Turkana, Kenya, in 1985. Later species include Paranthropus boisei in East Africa, discovered by Mary Leakey at Olduvai Gorge, Tanzania, in 1959, and Paranthropus robustus in South Africa, first found by Robert Broom in 1938. Males had a bony crest on the top of the skull anchoring massive chewing muscles. Brains were small, around 500 cubic centimetres.

The group branched from earlier australopithecines and lived alongside early Homo for more than a million years, until about 1.2 million years ago in East Africa and perhaps a little later in southern Africa. Chemical studies of their teeth show that P. boisei lived mostly on grasses and sedges, not on the nuts that its nickname 'Nutcracker Man' implies. Why they died out is uncertain. A cooler, drier, more open landscape may have cut their food supply, while Homo, with a broader diet and tools, adapted more flexibly. They show that early human evolution had several experiments going on at once, and that our own line was just one of them.