Chordates comprise lampreys, hagfishes, jawed fishes, and tetrapods, plus a variety of more unfamiliar and crucially important non-vertebrate animal lineages, such as lancelets and sea squirts. This will be the first book to synthesize, summarize, and provide high-quality illustrations to show what is known of the configuration, development, homology, and evolution of the muscles of all major extant chordate groups. Muscles as different as those used to open the siphons of sea squirts and for human facial communication will be compared, and their evolutionary links will be explained. Another unique feature of the book is that it covers, illustrates, and provides detailed evolutionary tables for each and every muscle of the head, neck and of all paired and median appendages of extant vertebrates. Key Selling Features: Has more than 200 high-quality anatomical illustrations, including evolutionary trees that summarize the origin and evolution of all major muscle groups of chordates Includes data on the muscles of the head and neck and on the pectoral, pelvic, anal, dorsal, and caudal appendages of all extant vertebrate taxa Examines experimental observations from evolutionary developmental biology studies of chordate muscle development, allowing to evolutionarily link the muscles of vertebrates with those of other chordates Discusses broader developmental and evolutionary issues and their implications for macroevolution, such as the links between phylogeny and ontogeny, homology and serial homology, normal and abnormal development, the evolution, variations, and birth defects of humans, and medicine.