Small-brained but bipedal early hominids that lived in southern and eastern Africa between five and two million years ago and showed similarities to both apes and humans

Early (4.2-1.2 MYA) bipedal hominids. E.g., "Lucy" is a famous australopithecine fossil discovery. Several species.

any species of the genus Australopithecus that lived in East and South Africa about 4.2 to 2.5 million years ago (i.e., Australopithecus afarensis).