A detailed study has been made of the oldest South African Upper Pleistocene hominid remains found in Acheulian context in a well-stratified sealed cave deposit, the Cave of Hearths, Makapansgat, Northern Transvaal. Possibly 55,000 years of age, the remains comprise a juvenile right mandibular body with teeth, and part of a right radius. The mandible is highly robust, markedly prognathous, has a slight to moderate bony chin, an appreciable planum alveolare, a low supraspinous foramen, large alveolar part with big tooth roots, parallel upper and lower borders, a superior transverse torus and poorly developed genial apophysis. The teeth are fairly large, narrow and elongate; M2 is smaller than M1; both molars have a +5 cusp pattern, and the first molar shows moderate taurodontism. There is good evidence that the jaw shows congenital lack of M3: after the Chinese Lantian jaw, this is the second oldest hominid mandible and the first African fossil man with this feature. The radius has a relatively large head atop a disproportionately narrow neck; marked angulation of neck on shaft; and a strongly developed bicipital tubercle. The remains show a cluster of features which ally them with African Neandertaloids and earlier hominids of N.W. Africa. These geographically widespread African remains may represent a transitional population between H. erectus and H. sapiens neanderthalensis. This population has been called by Campbell, this author and others H. sapiens rhodesiensis (after the first-discovered specimen from Broken Hill): to this taxon the Cave of Hearths bones are tentatively assigned.