into the Awash River. Taieb recovered several fossils in the area and led a party back to Hadar in May 1972. In October 1973, 16 individuals with the International Afar Research Expedition (IARE) arrived at Hadar and camped there for two months during which the first hominin fossil was found. (Taieb claims in his 1985 book Sur la Terre des premiers Hommes to have discovered the Hadar fields in 1968, but Kalb argues that claim to be incorrect.) The IARE party examined a series of sedimentary layers called the Hadar Formation, which was dated to the late Pliocene to early Pleistocene epochs (3.5 to 2.3 million years ago). The anthropologist Donald Johanson, a member of the 1973 expedition to Hadar, returned the next year and discovered the fossil hominin "Lucy" in the late fall of 1974. He spotted a right proximal ulna in a gully, followed by an occipital bone, a femur, some ribs, a pelvis, and a lower jaw. Within two weeks, nearly 40% of the hominoid skeleton had been identified and cataloged. Lucy is the most famous fossil to have been found at Hadar. Lucy is among the oldest hominin fossils ever discovered and was later given the taxonomic classification Australopithecus afarensis. (The name 'Lucy' was inspired by the song "Lucy in the Sky with Diamonds" by The Beatles, which happened to be playing on the radio at base camp.) In 1975, Donald Johanson made another discovery at a nearby site in Hadar: 216 specimens from approximately 17 individuals, most likely related and varying in age, called AL 333 (colloquially referred to as the "First Family"). About thirty years later in nearby Dikika, another Australopithecus afarensis fossil skeleton was found in a separate outcrop of the Hadar Formation across the Awash River from Hadar. The skeleton is of a three-year-old girl later named "Selam," which means peace in Amharic Ethiopian languages. Specimens and inferences In 1973 and 1974 when the first anatomical discoveries were made, their size and shape pointed towards a variety of taxa, but further research has confirmed that only one hominin taxon is present here. The first find there was a fossil knee joint estimated to date from 3.4 million years ago. Since then, the Hadar research area has yielded 370 specimens of A. afarensis, one specimen of Homo, and 7571 additional vertebrate specimens. The specimens recovered display a variety of different primitive cranial post