Preface Acknowledgments 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? 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? 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 4. Cetartiodactylan Diversity, Evolution, and Adaptations Early Whales Had Legs! Crown Cetacea (Neoceti) Evolutionary Trends Structural and Functional Innovations and Adaptations Mating and Social Systems, Reproduction, and Life History 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 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 Exception Glossary Further Reading and Online Sources Illustration Credits Index.