Criteria developed to distinguish between the mandibles and mandibular teeth of sheep and goats are evaluated using modern specimens from the collections of the National Museum of Natural History and the Field Museum of Natural History. Certain teeth prove to be quite reliable in this regard (dP3, P3, P4). Other dental elements, however, are not reliable and should not be used in dental based identifications of these closely related species (dP4, M1, and mandibular bones). Overall, the identification of sheep dentition using these criteria is more reliable than it is for goats. However, the generally greater likelihood of incorrect identification of goat teeth and mandibles means that specimens identified as sheep are likely to contain high proportion of misidentified goats. Both the proportion of remains that can only be classified as [`]Ovis-Capra' and the proportion of incorrectly identified teeth and mandibular bones varies with age, with identifications of younger and older animals less reliable than those of animals in the 1.5-6 year age range. Reliability of identifications increases when more criteria and more elements are used. Identifications based on whole mandibles with complete tooth rows are quite reliable. However, the proportion of specimens likely to be classified as [`]Ovis-Capra' also increases in whole mandible identifications, especially in goats. Systematic differences in the proportions of indeterminate and incorrect identifications have a significant impact on species-level dentition based harvest profiles. Recommendations are made for the use of dentition and long bone based harvest profiles in the study of sheep and goat exploitation strategies.
