New discoveries of Australopithecus at Maka in Ethiopia

Abstract

THE taxonomy of Australopithecus afarensis, the oldest known hominid species, has been a matter of debate since its description in 1978 (ref. 1). Some authorities regard all specimens assigned to A. afarensisas belonging to a single taxon^2–4whereas others regard the Tanzanian and Ethiopian specimens as each representing a different species^5,6. Further controversy surrounds the issues of sexual dimorphism and locomotion among these hominids. Resolution of these problems would shed light on hominid phylogeny in general and on the ancestry of later Australopithecus and Homo. Fossils discovered in the Afar of Ethiopia in 1990 constitute the first major addition to the 3–4 million year (Myr) hominid record since the 1970s. We report here the discovery of new fossils from Maka, dated to 3.4 Myr ago, which provide powerful support for the interpretation of A. afarensis as a single, ecologically diverse, sexually dimorphic, bipedal Pliocene primate species whose known range encompassed Ethiopia and Tanzania.