Until now , Australopithecus , nicknamed `` Lucy , '' was the oldest fossil studied by scientists seeking to explain human evolution . Scientists have unveiled a 4.4 million - year - old skeleton of a hominid monkey . The fossil , says Ardi , may be the oldest hominid skeleton ever found . It replaces Lucy , a much - publicized skeleton that dates back about 3 million years . Scientists : Ardi suggests monkeys and chimps evolved from a common ancestor .
Scientists have unveiled a 4.4 million - year - old skeleton of a hominid monkey . The fossil , says Ardi , may be the oldest hominid skeleton ever found . It replaces Lucy , a much - publicized skeleton that dates back about 3 million years . Scientists : Ardi suggests monkeys and chimps evolved from a common ancestor .