sentences:  The shift towards post-canine megadontia dates back to about 4-5 million years ago with the discovery of "Ardipithecus ramidus" in the Middle Awash region of Ethiopia.Distinctive features in "A. ramidus" such as dentition with reduced canines, the skull, hindlimb and forelimb suggest it to be near the split between the chimpanzee and hominin lineages.It was the origin of "Australopithecus africanus", found in several regions of South Africa (Taung, Sterkfontein, Makapansgat) 2-3 million years ago that first demonstrated the enlargement of the pre-molars and molars.