Abstract: This research explored the sexual differences and allometric growth pattern of hip bones in rhesus macaques. Hip bone specimens were obtained from 66 skeletons of Macaca mulatta (21 male and 45 female). Four innominate variables were selected, and SPSS (Version 20.0) was used for statistical analysis. The one-way analysis of variance was used to compare the mean of each variable between the sexes, and the stepwise function analysis was used to establish discriminant functions that can be used to estimate sex for the hip bones. Most of measurements of hip bones of mature rhesus monkey were shown to be sexually dimorphic (P<0.01), while those of immature were not sexually dimorphic. Innominate bones of immature monkeys of both sexes resembled pelves of mature males. Three patterns of allometric growth in the innominate were tested in this study. Stepwise analysis showed that using the functions with only a single hip variable would effectively identify the sex of the adult monkey, with a correct classification rate of 87.0%. In the sample of Macaca mulatta pelves studied here, it is not possible to distinguish unfused male pelves from unfused female pelves. Sexual dimorphism in the pelvis of Macaca mulatta is related to the interaction between locomotory and obstetrical function, as the female pelvis acquires morphological features during postnatal development that differentiates them from mature male pelves and from immature pelves of both sexes.

Key words: Macaca mulatta; Hip bones; Sex differences; Allometry