Topic summary
A. ramidus
Extracted from the Wikipedia article Ardipithecus ramidus.
Description
A. ramidus had a small brain, measuring 300–350 cc (18–21 cu in). This is slightly smaller than a modern bonobo or chimp brain, but much smaller than the brain of Australopithecus—about 400–550 cc (24–34 cu in)—and roughly 20% the size of the modern human brain. Like chimps, the A. ramidus face was much more pronounced (prognathic) than modern humans. The size of the upper canine tooth in A. ramidus males was not distinctly different from that of females (only 12% larger), in contrast to the sexual dimorphism observed in chimps where males have significantly larger and sharper upper canines than females.