s of africanus are much larger than those of humans, they are far more similar to human teeth than to those of apes. The shape of the jaw is now fully parabolic, like that of humans, and the size of the canine teeth is smaller compared to afarensis. Australopithecus garhiThis species was named in April 1999. It is known from a partial skull. The skull differs from previous australopithecine species in the combination of its features, notably the extremely large size of its teeth, especially the rear ones, and a primitive skull morphology. Some nearby skeletal remains may belong to the same species. They show a humanlike ratio of the humerus and femur, but an apelike ratio of the lower and upper arm. Australopithecus afarensis and africanus, and the other species above, are known as gracile (slender) australopithecines, because of their relatively lighter build, especially in the skull and teeth. Despite this, they were still more robust than modern humans. Australopithecus aethiopicusA. 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. It may be an ancestor of robustus and boisei, but it has a confusing mixture of primitive and advanced traits. The brain size is very small, at 410 cc, and parts of the skull, particularly the back portions, are very primitive, most resembling afarensis. Other characteristics, like the massiveness of the face, jaws and single tooth found, and the largest sagittal crest (a bony ridge on top of the skull to which chewing muscles attach) in any known hominid, are more like that of A. boisei.Australopithecus robustusA. 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. ...
