• Scapula;
  • Shoulder;
  • Australopithecus;
  • Sterkfontein;
  • Reconstruction


Until recently the two broken parts of the Sterkfontein A. africanus scapular fragment, STS 7, were separated and oriented towards one another at an unnatural angle in the partially encasing breccia matrix. Removal of the latter and reconstruction have allowed a reassessment of, and additions to, previously published descriptions and measurements. Several hypotheses, based mainly on features of the coracoid process, are presented for testing: the gracile australopithecine thoracic shape, scapular placement and angulation of the clavicle to the scapula more closely resembled the condition in extant Pongidae than that in modern man; an apomorphous (i.e., derived) development of the acromio-coracoid “cuff” in Pan is a specialization for knuckle-walking; its absence in STS 7 suggests that the common ancestor of Australopithecus and Homo was not a knuckle-walker.