PROXIMAL FEMUR OF AUSTRALOPITHECUS-AFRICANUS FROM MEMBER-4, MAKAPANSGAT, SOUTH-AFRICA

A left proximal femur (MLD 46) from Member 4, Makapansgat, South Afric a is described and analyzed. It consists of the head, neck, and a smal l segment of the shaft that extends to just below the lesser trochante r. The femur exhibits degenerative joint disease in the form of margin al osteophyte formation and thus its taxonomic identity has been somew hat obscured. Consideration of all like-sized mammalian femora from Ma kapansgat suggests that the femur is that of either a felid or hominid . Comparison of MLD 46 to femora of extent and extinct felids reveals that MLD 46 does not possess two morphological features that are chara cteristic of felids, namely a deep, prolonged trochanteric fossa and a high neck-shaft angle. Simple shape variables (ratios) and multivaria te analyses consistently place MLD 46 with modern and fossil hominids, and most closely align it with the australopithecines. We conclude th at the femur is most reasonably attributable to Australopithecus afric anus, which is the only hominid yet identified from Makapansgat. Despi te its pathological condition, MLD 46 is the most complete proximal fe mur known for A. africanus, thereby permitting further morphological c omparisons with homologues of A. afarensis and Paranthropus. Marginal osteophytes of mammalian femoral heads characteristically occur in ind ividuals of advanced age, suggesting that MLD 46 may have lived some t ime with the disease. Finally, MLD 46 is considerably larger than the previously described specimen, Sts 14, from Sterkfontein Member 4. The re may be as great a contrast in body size in A. africanus as there is between the large and small specimens of A. afarensis. (C) 1993 Wiley -Liss, Inc.