Describing the diversity and features of various vertebrate groups, ranging from the oldest living fishes to the relatively more recent evolution of mammals, this book covers anatomical systems including organs and tissues, as well as their function and differentiation in various vertebrate groups. The authors also discuss the evolution of vertebrate groups from the earliest extinct ancestors to current living vertebrates. The book contains illustrations to clarify various issues as well as discussions of vertebrate features that enable adaptation to aquatic and terrestrial environments.