Introduction

This chapter describes the Halecomorphi-Teleostei sister-group relationship. It also describes new classification and thus group turtles and archosaurs in the clade Archosauromorpha, which is the sister-group of the clade Lepidosauromorpha. Several other studies have provided information on the musculature of the chordates, but most of them concentrated on a single taxon or on a specific subgroup of muscles. Furthermore, none of those works covered in detail all the skeletal muscles of all major extant groups of chordates. The chapter suggests that the information provided will stimulate researchers to develop a detailed ontology of the skeletal muscles of chordates, as well as to undertake studies about the evolution, homologies, and development of these muscles and of other vertebrate anatomical structures in general. It contributes to the revival of the field of vertebrate chordate myology, which was too often neglected in the late twentieth century.