An early Australopithecus afarensis postcranium from Woranso-Mille, Ethiopia

10.1073/pnas.1004527107 Only one partial skeleton that includes both forelimb and hindlimb elements has been reported for . The diminutive size of this specimen (A.L. 288-1 ["Lucy"]) has hampered our understanding of the paleobiology of this species absent the potential impact of allometry. Here we describe a large-bodied (i.e., well within the range of living ) specimen that, at 3.58 Ma, also substantially antedates A.L. 288–1. It provides fundamental evidence of limb proportions, thoracic form, and locomotor heritage in . Together, these characteristics further establish that bipedality in was highly evolved and that thoracic form differed substantially from that of either extant African ape.