Cover; Title Page; Copyright Page; Dedication Page; Table of Contents; Preface; Acknowledgments; Chapter 1. Marine Mammals; Major Groups of Marine Mammals; Discovering, Naming, and Classifying Marine Mammals; Reconstructing the Hierarchy of Marine Mammals; Adaptations and Exaptations; What is a Species and how do New Species Form?; Where do they Live and why are they where they are?; Chapter 2. Past Diversity in Time and Space, Paleoclimates, and Paleoecology; Fossils and Taphonomy; The Discovery of the First Fossil Marine Mammal (a Whale); The Importance of Fossils.How do we Know the Age of a Fossil?How do we Know where Marine Mammals were?; Marine Mammal Diversity and Communities through Time; What Led Marine Mammals Back to the Sea?; Chapter 3. Pinniped Diversity, Evolution, and Adaptations; The Earliest Pinnipeds: Webbed Feet or Flippers?; Crown Pinnipeds; Desmatophocids: Extinct Phocid Relatives; Evolutionary Trends; Structural and Functional Innovations and Adaptations; Mating and Social Systems, Reproduction, and Life History; Chapter 4. Cetartiodactylan Diversity, Evolution, and Adaptations; Early Whales Had Legs!; Crown Cetacea (Neoceti).Evolutionary TrendsStructural and Functional Innovations and Adaptations; Mating and Social Systems, Reproduction, and Life History; Chapter 5. Diversity, Evolution, and Adaptations of Sirenians and Other Marine Mammals; Walking Sea Cows!; Crown Sirenia; Evolutionary Trends; Structural and Functional Innovations and Adaptations; Mating and Social Systems, Reproduction and Life History; Desmostylians; Aquatic Sloths; Marine Otters; Polar Bears; Chapter 6. Ecology and Conservation; What Marine Mammals Eat and what Eats them; Interactions between Human and Marine Mammals: Lessons Learned.Extinction: The Rule, not the ExceptionGlossary; Further Reading and Online Sources; Illustration Credits; Index.