The present investigation assesses a number of explanations for the patterns of variability in dental dimensions. Coefficients of variation were calculated for mesiodistal and buccolingual diameters in a sample of 105 Papio ursinus crania (52 male, 53 female). Variability profiles consisting of arrays of values of coefficients of variation were evaluated by means of Friedman's two-way analysis of variance and Kendall's coefficient of concordance. Although molar teeth were found to be the most dimensionally stable, our results failed to support either the morphogenetic field theory or the occlusal complexity hypothesis. The data presented here are generally supportive of Pengilly's phenotypic complexity theory. However, speciesspecific clustering patterns found in our regressions of dimensional variability on mean tooth size suggest that differences in variability levels might be related to differences in selective pressures.