40% of the skeleton of an individual Australopithecus afarensis. The specimen was discovered in 1974 at Hadar in the Awash Valley of Ethiopia's Afar Depression. Lucy is estimated to have lived 3.2 million years ago.
The discovery of this hominid was significant as the skeleton shows evidence of small skull capacity akin to that of apes and of bipedal upright walk akin to that of humans, providing further evidence that bipedalism preceded increase in brain size in human evolution. In 1994, a new hominid, Ardi, was found, pushing back the earliest known hominid date to 4.4 million years ago, although details of this discovery were not published until October 2009.