Is the modern monkey or ape similar to Australopithecus?
Australopithecines had brain sizes a bit larger than chimps. Their faces were somewhat apelike. However, they were fully erect and bipedal, not knucklewalkers, and their hands and arms were far more “human” than “ape”, and their teeth were closer to human than ape. Aside from full bipedality, some of the specific points of comparison are the proportions of upper to lower limbs (also known as the “humerofemoral index”) and the proportion of the bones in the forearm to the upper arm; the wrist bones, which allow more lateral extension in humans than in apes; the length and opposability of the big toe; the relative height of the crowns of the teeth and how far the canine teeth project; and whether the row of teeth in the lower jaw takes a rounded “U” shape, as apes have, or a more square “|_|” shape, as humans have. For the limb proportions, the australopithecines are clustered directly between us and chimps and gorillas, but lie closer to us, with forearm:upper arm proportions unique to
