When Lucy and other Australopithecines were walking around Ethiopia 3.4 million years ago, they may have encountered another hominin species that still climbed trees and also walked, but with a gait more like an ape than their bipedal neighbors.

Did Australopithecus afarensis have opposable big toes?

afarensis, the latest find has an opposable big toe — rather like a thumb on the foot — that would have allowed the species to grasp branches while climbing. Modern apes have similar toes, but the youngest hominin previously known to have them is Ardipithecus ramidus, which lived about 4.4 million years ago.

Which primates have opposable big toes?

Primates — chimpanzees, gorillas, orangutans, and humans, to name a few — share the common trait of hands designed with opposable thumbs. This adaptation is critical to the survival of monkeys and apes who gather and grasp their food as they make their way from tree to tree.