ABSTRACT
This chapter describes the book Muscles of Vertebrates (Diogo and Abdala 2010), which was largely based on an extensive review of the available literature. It presents the groundwork for a general discussion of the early evolution of the head and neck muscles of vertebrates. The chapter also describes the commonly accepted phylogenetic hypothesis that living hagfishes and lampreys are more closely related to each other than to other living vertebrates. It discusses the body musculature of nonosteichthyan vertebrates. Living lampreys and living hagfishes lack paired fins and their body musculature is extremely simple. The chapter also discusses new and crucial findings related to the origin and early evolution of the cephalic muscles of vertebrates based on dissections of representatives of all the major clades of cyclostomes and chondrichthyans.
