ABSTRACT
This chapter provides data about the evolution and homologies of all hindlimb muscles of representatives of each major tetrapod group, such as urodeles, anurans, turtles, lepidosaurs, crocodylians, birds, monotremes, marsupials, and placentals. It compares the hindlimb muscles of the following key taxa, chosen from among the many tetrapod taxa dissected by the author and colleagues: the salamander Ambystoma mexicanum, the lizard Timon lepidus, the marsupial Didelphis virginiana, the placental rodent Rattus norvegicus, and modern humans Homo sapiens. The chapter summarizes the major differences between, and hypotheses of homology within, the hindlimb muscles of tetrapods. The hindlimb muscles present in placentals such as rats/mice and humans are, with very few exceptions, also present in marsupials such as opossums. One of the few major controversies about the homologies between the hindlimb muscles of marsupials and placentals concerns the piriformis.
