An authoritative illustrated guide to the mighty reptiles that dominated the seas of the Mesozoic for 185 million yearsNew discoveries are revealing that many ancient oceangoing reptiles were energetic animals capable of inhabiting an array of watery habitats and climates, including polar winters. The Princeton Field Guide to Mesozoic Sea Reptiles provides the most up-to-date and comprehensive coverage of the great Mesozoic groups that commanded the seas for tens of millions of years. This incredible field guide covers 435 species and features stunning illustrations of swimming reptiles ranging in size from little lizards to others with great necks longer than their bodies. It discusses the history of sea reptiles through 185 million years of the Mesozoic, their anatomy, physiology, locomotion, reproduction and growth, and extinction, and even gives a taste of what it might be like to travel back to the Mesozoic. This one-of-a-kind guide also challenges the common image of these reptiles as giants of the prehistoric waters, showing how the largest weighed far less than today's biggest whales.