(b) / 4.4 million years ago / Discovered in December 17, 1992 / Ethiopia / Research cast

Ardipithecus ramidus was discovered in 1992, as the oldest known human ancestor at that time. In 2009, a partial skeleton and other fossils revealed that Ar. ramidus represents a newly recognized primitive evolutionary grade ancestral to humans. Ar. ramidus possessed a grasping foot as in apes, but walked upright like humans. It appears to retain characteristics close after the human-chimpanzee split. The exhibited specimen is an upper right third molar, the first Ar. ramidus fossil found at Aramis, Afar Rift, Ethiopia.