The Hindlimb Musculature of the White-Fronted Amazon (Amazona albifrons, Psittaciformes)

Abstract

Abstract The hindlimb musculature of six specimens of Amazona albifrons was dissected in order to (1) provide a detailed myological description, (2) provide a preliminary study and basis for a systematic analysis of the Psittaciformes, and (3) point out any myological peculiarities that might be associated with their unusually manipulative feet. Notable features include a peculiar positioning of M. extensor brevis digiti IV, a previously undescribed muscle to digit III, a peculiar arrangement of the short extensors of the hallux, and a branch of M. extensor digitorum longus to the hallux. These features are believed to be associated either with the zygodactyl digit configuration or the requirement of finer control over the individual digits.