Hadar is one of the iconic places of Ethiopia with paleontological discoveries. The Hadarpaleontological discoveries include partial skeletons of Australopithecus afarensis, a key species in human evolution. Major paleontological work began at Hadar in the early 1970s and was led by the American anthropologist Donald Johanson. His team discovered a 40-percent-complete female skeleton of Australopithecus afarensis that became popularly known as Lucy. Dated to 3.2 million years ago, the remains provided further evidence that, in human evolution, walking on two legs (bipedalism) preceded increased brain size. The pelvis and leg bones indicate upright posture, but the skull bones reveal a limited cranial capacity similar to that of modern chimpanzees. The Australopithecus afarensis-bearing levels at Hadar range from 3.4 to 2.9 million years old and include more than 200 fossils from a single site (Afar Locality 333), representing at least nine adults and four juveniles deposited at the same time. The site has also yielded the earliest known remains of the human genus, Homo, which dates to 2.3 million years ago, along with some of the earliest known evidence of tool use.