The brain size is very small, at 410 cc, and parts of the skull, particularly the hind portions, are very primitive, most resembling afarensis . Australopithecus robustus A. robustus had a body similar to that of africanus , but a larger and more robust skull and teeth. It existed between 2 and 1.5 million years ago. The massive face is flat or dished, with no forehead and large brow ridges. It has relatively small front teeth, but massive grinding teeth in a large lower jaw.
Most specimens have sagittal crests.
Its diet would have been mostly coarse, tough food that needed a lot of chewing. The average brain size is about 530 cc. Bones excavated with robustus skeletons indicate that they may have been used as digging tools. It was similar to robustus , but the face and cheek teeth were even more massive, some molars being up to 2 cm across. The brain size is very similar to robustus , about 530 cc.