Capuchin monkeys are known to exhibit sporadic bipedalism while performing specific tasks, such as cracking nuts. The bipedal posture and locomotion cause an increase in the metabolic cost and therefore increased blood supply to lower limbs is necessary. Here, we present a detailed anatomical description of the capuchin arteries and veins of the pelvic limb of Sapajus libidinosus in comparison with other primates. The arterial pattern of the bearded capuchin hind limb is more similar to other quadrupedal Cebus species. Similarities were also found to the pattern observed in the quadruped Papio, which is probably due to a comparable pelvis and the presence of the tail. Sapajus' traits show fewer similarities when compared to great apes and modern humans. Moreover, the bearded capuchin showed unique patterns for the femoral and the short saphenous veins. Although this species switches easily from quadrupedal to bipedal postures, our results indicate that the bearded capuchin has no specific or differential features that support extended bipedal posture and locomotion. Thus, the explanation for the behavioral differences found among capuchin genera probably includes other aspects of their physiology.

Pesq. Vet. Bras. 32(Supl. The anatomical comparative studies among the primates are important for the investigation of ethology, evolution, taxonomy, and comprehension of tools by hominoids. Especially the anatomical knowledge of Cebus contributes to conservation of the species, and to development of surgical procedures and clinical treatments of these animals, as they frequently are victims of automobile accidents. Recent anatomical studies came to a wrong conclusion regarding behavioral traits of Cebus, ascribed to few data available in previous literature. Therefore, to provide anatomical data and to support the other sciences related to anatomy, and to develop surgical and/or clinical procedures, we described the nerves of the legs of Cebus foccusing on their position and trajectory, as wll as innerved muscles, and compared these results with those of humans and other primates. Eight adult capuchin specimens were used for this study. The anatomical comparative study of the leg's nerves of Cebus demonstrated that, in general, structural organization of the nerves is similar among the four primates analyzed here (Cebus, chimpanzees, baboons and humans), which might be attributed to the fact that the all four primates have similar body structures. However, nerve trajectory and muscles innervation in Cebus was more similar to baboons. vimento de procedimentos cirúrgicos e tratamentos clí-nicos destes animais, pois são frequentemente vítimas de acidentes automobilísticos. Recentemente, estudos sobre características comportamentais de Cebus indicaram conclusões erradas sobre sua anatomia, o que pode ser atribuído aos poucos dados disponíveis sobre a anatomia desses animais na literatura especializada. Portanto, para fornecer dados anatômicos e fornecer suporte para as outras ciên-cias relacionadas com a anatomia e também desenvolver procedimentos cirúrgicos e/ou clínicos, foram descritos os nervos das pernas de Cebus com enfoque sobre a posição, a trajetória e os músculos inervados, e comparar esses resultados com os dos humanos modernos e outros primatas. Oito espécimes adultos de macacos-prego foram usados para este estudo. O estudo anatômico comparativo dos nervos da perna de Cebus demonstrou que, em geral, a organização estrutural dos nervos é semelhante entre os quatro primatas aqui analisados (Cebus, chimpanzés, babuínos e humanos modernos), o que pode ser atribuído ao fato de