Portrays the life and evolutionary times of marine mammals - from giant whales and sea cows that originated 55 million years ago to the deep diving elephant seals and clam-eating walruses of modern times. This title gives an account of the origin of various marine mammal lineages, some extinct, others extant but threatened.

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

"Over the past 55 million years, mammals have returned to the sea many times and in many places. Annalisa Berta leads readers through this parade of transitions, highlighting how marine mammals have met the evolutionary challenge of living an aquatic life in a variety of ways. Return to the Sea weaves ecology, anatomy, and evolution into an ideal entry point for anyone interested in knowing more about one of the most fascinating phenomena in macroevolution."--Nicholas D. Pyenson, National Museum of Natural History, Smithsonian Institution"Berta is to be congratulated. She drew on her vast knowledge of marine mammals and their evolution to write an excellent, readable introduction to the group, including the latest discoveries."--J.G.M. Thewissen, Northeast Ohio Medical University"This wide-ranging and up-to-date survey of marine mammal biology and evolution is a fine introduction to the subject for undergraduates and anyone interested in mammals of the sea."--Daryl P. Domning, Howard University

"Engaging... Stimulating... A compelling story of the history and biology of marine mammals that will delight while it informs readers." -- Alexander J. Werth Bioscience "A good introduction to marine mammal evolution." -- Ian Paulsen The Guardian "Rarely does one have the opportunity to read a book that is written in an enjoyable and accessible way, scientifically accurate, and based in a wide and updated range of literature." -- Carolina Loch, University of Otago, New Zealand Marine Mammal Science "The writing is simple and informative, the line drawings and other illustrations are excellent, and we have here a primer of what it is to be a marine animal..." -- Bernd Wursig The Quarterly Review of Biology