Anatomical study of the forelimb of capybara (Hydrochoerus hydrochaeris Linnaeus, 1766)

Abstract

The study aimed to provide a detailed anatomical description of the forelimb of the capybara using gross anatomy, radiography images, and three-dimensional reconstruction. Four adult animals were used for macroscopic dissections, one for the acquisition of radiographic images and reconstructions, and one specimen for bone descriptions. The results showed the anatomical details of the scapula with a developed hamate process and the absence of a clavicle. Radius and ulna do not fuse. The hand has five metacarpal bones, and the first digit is rudimentary. The proximal row of the carpal comprises the intermedioradial, ulnar, and accessory carpal bones, and the distal row comprises four carpal bones. The muscles present a general pattern similar to other groups of domestic animals; however, the absence of the accessory head of the triceps brachii muscle has been demonstrated. The resulting images provided excellent detail of the main anatomical structures of the capybara’s thoracic limb. The illustrations in the present study are a valuable reference for the interpretation of normal and pathological imaging studies in the species in the present study.