This book focuses on the first vertebrates to conquer the land, and on their long journey to become fully independent from the water. It will trace the origin of tetrapod features and try to explain how and why they transformed into organs that permit life on land. The classic idea of early land vertebrates is that they were similar to modern amphibians. Right or wrong, the vast majority of early tetrapods are therefore classified as amphibians (or more precisely their stem taxa). Accordingly, this book is centered on early amphibian evolution, a topic that effectively includes all early tetrapods, and it will also analyze facts and opinions on the origins of modern amphibians. The major part of the story covers events that occurred over the past 370 million years, but it is far from restricted to paleontology.
My own motivation to study the amphibian fossil record derives in large part from a fascination with the development, ecology, and evolution of their modern representatives. Therefore I consider many topics that can only be covered by examination of extant animals: features of the soft body, functions of organs that mediate breathing, feeding, hearing, and locomotion, the morphogenesis of body parts, larval development, metamorphosis, and ecology.
