MORPHOLOGICAL AFFINITIES OF THE PROXIMAL ULNA FROM KLASIES RIVER MAINSITE - ARCHAIC OR MODERN

The Middle Stone Age (MSA) asociated hominids from Klasies River Mouth (KRM) have taken on a key role in debate about the origins of modern humans, with their craniofacial remains seen as either representing th e earliest well-dated modern humans in southern Africa or orthognathic late archaic humans. Diagnostic postcranial remains from Klasies are few, but one specimen-a proximal right ulna from the lower SAS member- is useful For assessing the morphological affinities of these hominids . Canonical variates analysis using 14 proximal ulnar dimensions and c omparative data from European, west Asian and African archaic humans, and Levantine Mousterian, European Upper Paleolithic, African Epipaleo lithic and diverse recent modern human samples (many of recent African descent) were employed to assess the morphological affinities of this specimen. Results suggest an archaic total morphological pattern for the Klasies ulna. Analysis of diaphyseal cross-sectional geometry reve als an ulnar shaft with relatively thick cortical bone, but the specim en cannot be readily distinguished from Neandertals or early anatomica lly modem humans on the basis of shaft cross-sectional properties. If the isolated ulna from Klasies is indicative of the general postcrania l morphology of these hominids, then the MSA-associated humans from KR M may not be as modern as has been claimed from the craniofacial mater ial. It ii: possible also that the skeletal material from KRM reflects mosaic evolution-retention of archaic postcranial characteristics. pe rhaps indicating retention of archaic habitual behavior patterns, in h ominids that were becoming craniofacially modern. (C) 1996 Academic Pr ess Limited