Australopithecus - Morphology

Morphology

The brains of most species of Australopithecus were roughly 35% of the size of that of a modern human brain. Most species of Australopithecus were diminutive and gracile, usually standing between 1.2 to 1.4 m (3 ft 10 in to 4 ft 7 in) tall. In several variations of Australopithecus there is a considerable degree of sexual dimorphism, in this case males being larger than females.

Modern hominids do not appear to display sexual dimorphism to the same degree — particularly, modern humans display a low degree of sexual dimorphism, with males being only 15% larger than females, on average. In Australopithecus, however, males can be up to 50% larger than females. New research suggests that sexual dimorphism may be less pronounced than this, but there is still debate on the subject.