Final answer:
If the dates for Australopithecus sediba are correct, it was contemporary with Australopithecus afarensis in East Africa around 2 million years ago. Both species show characteristics reflecting evolutionary changes, with A. sediba possibly being an ancestor of Homo erectus and Homo ergaster.
Step-by-step explanation:
If the dates for Australopithecus sediba from South Africa are correct, that species was contemporaneous with Australopithecus afarensis from East Africa. A. sediba and A. afarensis coexisted around 2 million years ago (mya), providing a fascinating look into our evolutionary history. A. afarensis is well-known for the famous fossil named "Lucy" and represents an important part of the hominin fossil record, reflecting trends in evolutionary development such as the reduction of dentition and jaw size from earlier species.
While A. afarensis had smaller canines and molars compared to apes and a brain size similar to that of a modern chimpanzee, it also showed evidence of bipedalism, an important trait shared with later hominins. Meanwhile, A. sediba is known for its mix of humanlike features, such as its pelvis and hands, and more primitive traits, like a chimpanzee-like foot, and could be a direct ancestor of Homo erectus and Homo ergaster.