INCISOR MICROWEAR OF SUMATRAN ANTHROPOID PRIMATES

Several studies have suggested that incisor microwear reflects diet an d feeding adaptations of anthropoids. However, such studies have been largely qualitative, and interpretations have relied on anecdotal refe rences to diet and tooth use reported in the socioecology literature. The current study relates incisor microwear in four anthropoid primate s to specific ingestive behaviors and food types. Central incisor cast s of wild-shot museum specimens of Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomasi were examined by scanning elect ron microscopy, and analyzed using a semiautomated image analysis proc edure. Microwear patterns were used to generate predictions regarding diet and anterior tooth use. These predictions were evaluated using da ta collected during a 1 year study of feeding behavior of these same t axa in the wild (Ungar, 1992, 1994a,b). Results suggest that (1) ename l prism relief is associated with the effectiveness of etching reagent s in foods, (2) dental calculus buildup results from a lack of incisor use and perhaps the ingestion of sugar-rich foods, (3) striation dens ity varies with degree of anterior tooth use in the ingestion of abras ive food items, (4) striation breadth is proposed to relate to the rat io of exogenous grit to phytoliths consumed; and (5) preferred striati on orientation indicates the direction that food items are pulled acro ss the incisors during ingestion. It is concluded that incisor microwe ar studies can contribute to the understanding of diets and feeding be haviors of extinct primates. (C) 1994 Wiley-Liss, Inc.