Ardipithecus ramidusThe earliest known hominid ancestor of Homo sapiens, who predates Australopithecus afarensis (known as Lucy, of the Olduvai Gorge) by 1 million years. Ardipithecus was discovered in 1994 by T White and A Walker in Chad, and believed to have lived 4.4 million years ago in the dense African woodlands. A ramidus represents a paradigm shift in paleoanthropology, in that the newest data suggests that man did not evolve from chimps, but rather that we shared a common ancestor.
Indirect evidence suggests that A ramidus was bipedal, and that some were 122 cm tall. The teeth are intermediate between those of earlier apes and A afarensis. Other fossils found with A ramidus indicate that it may have been a forest dweller; this may force modification of current theories about why hominids became bipedal, which previously linked bipedalism to a move to savannahs.