Sex differences in permanent mandibular tooth development in Macaca nemestrina

Sex differences in dental maturation prior to and during adolescence in 40 unrelated Macaca nemestrina were investigated. The data consisted of mixed longitudinal cephalometric films taken at regular intervals during this period. The mandibular premolars and molars presented the following sequence of initial calcification: M1 P3 (M2 P4) M3. In all stages of development, females tended to mature earlier than males, although only 10 of the 22 stages studied were significantly different. Of these, M3 crown completion, M1 cleft formation, and M3 apical closure were the most reliable for discriminating between sexes. The rate of formation of all teeth, with the exception of M3, was faster in the females than the males, and in both sexes the teeth completed their formation during adolescence. It was suggested that these sex differences in dental maturation may be associated with differences in the timing of hormone secretion, i.e., menarche

Comparative anatomy of the thigh nerves of Cebus libidinosus (Rylands et al., 2000)

Non-human primates have constituted an important group among animals subjected to various studies. Ethological, evolutionary and paleontological studies have revealed changes in anatomical structures linked to the evolution of primates, considered in studies on the comparative anatomy between Cebus libidinosus and other neotropical monkeys or those from the Old World, and the detailed knowledge on their anatomy may represent an important factor for their preservation and protection when the animals are brought to veterinary clinics after accidents or illnesses. In terms of veterinary importance, sometimes these animals arrive in the veterinary medical clinics after accidents, needing surgery or clinical treatment, but the little data available on anatomy has impaired the correct proceedings. The main justification for studies on C. libidinosus, is due to little information about the anatomy related to C. libidinosus in Brazilian and worldwide scientific literature. In this study, the distribution, enervation and path of the femoral and sciatic nerves of the pelvic limb (thigh) of C. libidinosus were studied and these results were compared with literature on the anatomy of humans, chimpanzees and baboons. In general, the enervation model of the four primates is identical, but in specific terms, the differences in enervations indicate evolution convergence closer to the branch of baboons in the evolutionary tree, and these data corroborate other comparative studies in relation to the same primates to vessels, muscles and nerves. In conclusion, the nerve organization in the thigh of C. libidinosus is identical to baboon, chimpanzee and homo, but more similar to baboon. The specific differences found indicate an ancient phylogenic origin to C. libidinosus and baboons (data corroborated by other studies)