The discussions provided in this chapter mainly concern the mandibular, hyoid, branchial and hypobranchial muscles of actinopterygians and basal sarcopterygians (see cladogram of Fig. 4.1; as explained in previous chapters, the epibranchial muscles sensu Edgeworth 1935 are absent in extant osteichthyans). Figures 4.3 to 4.8 provide an updated version of the schemes of Miyake et al. (1992), including representatives of some osteichthyan groups that were not considered in Miyake et al.’s paper, such as amphibians and amniotes. The information provided in these fi gures is complemented with that given in Tables 4.1-4.4.