Dental microwear of ten wild-shot chacma baboons (Papio urinus) form Northwest and Northern Privinces, South Africa was examined by scanning electron microscopy. All specimens were collected during the dry season, during which these primates exploit hypogeous (underground) food items, including tubers and corms. The microwear fabric of thisP. ursinus sample is characterized by high pitting frequencies and large microwear features. It differs significantly from those displayed by other terrestrially foraging papionins of the genusTheropithecus. Exogenous grit is hypothesized to be largely responsible for the observedP. ursinus wear pattern, which resembles the microwear profiles of durophagous primates. It is suggested that large microwear features and a high incidence of enamel pitting, which are generally held to represent a microwear “signature” of durophagy, may not always be indicative of hard-object feeding in anthropoid primates.