Robustus (an evolutionary dead-end and not an ancestor of Homo sapiens) was a hominid species that existed in southern Africa between 2.3 to 1.3 million years ago. The majority of A. Robustus fossils are found in three locations: Swartkrans, Dreimulen, and Kromdraai. Individual fossils have been found, but most of the fossils are cranial and dental remains.
Weight: 40 - 80 kg
Height: 1.1 - 1.3 meters
Cranial capacity: 530 cc
Habitat: Semiarid savanna
Physically, A. Robustus was stocky, had a heavy bone structure and relatively long arms. The bones of the skull and jaw were quite thick, and there were pronounced brow ridges. The species also had a sagittal crest that anchored large jaw muscles and a wide face which allowed these massive muscles to pass underneath the cheekbones. Also, the zygomatic arches flared, further widening the face. The foramen magnum was placed anteriorly indicating bipedalism. The species was sexually dimorphic.
Robustus had large, flat molars with thick enamel, and a parabolic dental arcade. The canines and incisors were relatively small. The generally held opinion is that Robustus was a vegetarian and its large jaw muscles and molars were adapted to a diet of coarse, tough plants processed by laborious chewing.
This species was first discovered and named by Dr. Robert Broom. He had a habit of buying fossils collected from a lime quarry worker. In 1938 he bought a jaw fragment that contained a molar. Noting the size of the molar he determined that it could not belong to an A. africanus specimen. Visiting the cave where the fragment had been found, Broom discovered a number of other cranial and mandibular fragments that were associated with the first. Because it was larger the known gracile species, he named it Robustus.
There is much debate over whether or not A. Robustus utilized tools. Fossil evidence suggests that the species would have been capable of the specific manipulations necessary for tool-making, but skeptics argue that Robustus wouldn?t have had the necessary mental capacity. Oldowan tools are often found in conjunction with Robustus, but Homo fossils tend to also be found in the same areas. If Robustus did use tools, these most likely would have been animal jawbones or sticks used for digging up tubers or termite fishing.
Australopithecus robustus is also referred to as Paranthropus robustus.