"Around 370 million years ago, a distant relative of a modern lungfish began a most extraordinary adventure: It emerged from the sea and laid claim to the land. Over the next 70 million years, this tentative beachhead became a worldwide colonization by an ever-increasing variety of four-limbed life. These first "tetrapods" are the ancestors of all vertebrate life on land. This book tells the rich and complex story of their emergence and evolution. Beginning with their closest relatives, the lobe-fin fishes such as lungfishes and coelacanths, Jennifer A. Clack defines what a tetrapod is, describes their anatomy, and explains how they are related to other vertebrates."--BOOK JACKET.