Morphological Studies of the Forelimb Skeleton of the Orange Rumped Agouti (Dasyprocta leporina Linnaeus, 1758)

Abstract

The aim of the study is to document the morphological details of the forelimb bones of the orange rumped agouti (Dasyprocta leporina). The bones were collected from 12 adult animals of both sexes. Each limb comprised of 47 bones (30 bones, 17 sesamoid bones). The clavicle was poorly developed while the metacromion process of the scapula was very well developed. The humerus was peculiar, displaying poorly developed deltoid tuberosity, teres tubercle and the crest of the humerus and complete absence of the musculospiral groove. The distal extremity of the humerus was wide and presented a well-developed lateral epicondyle. The radius and ulna were separated and the ulna was larger and longer. The radial tuberosity was absent and semilunar notch of the ulna was deeper. The proximal row of carpals comprised of only two bones viz., radio-intermediate and ulnar carpal along two sesamoid bones viz., radial and accessory sesamoid bones on the palmar face. The manus presented five long, relatively thin metacarpal bones and five digits. The first digit was shorter with two phalanges whereas the other digits presented three phalanges. In conclusion, the features in the forelimb bones of the D. leporina reflected a wide functional spectrum, which include fast running, digging and shoveling. However, predominant features of the forelimb typified the D. leporina as cursorial rodents.