3.9 to 3 million years ago
Apelike arms; spine, pelvis, and lower limbs suited for an upright stance and two-legged gait
Australopithecus afarensis is the species made famous by Lucy, a 3.18millionyearold partial skeleton found at Hadar, Ethiopia. You see more reduced canines and slightly thickened enamel, but afarensis still features a protruding, chimplike jaw, and its brain is only slightly larger than a chimpanzees. It has slightly longer arms and shorter legs than a human does, but its proportions are very much like those of a human. It has relatively curved fingers and toes.
Photograph at left and top by Kenneth Garrett