Told in rich detail and with gorgeous color recreations, this is the story of marine life in the age before the dinosaurs. During the Middle Triassic Period (247–237 million years ago), the mountain of Monte San Giorgio in Switzerland was a tropical lagoon. Today, it is a UNESCO World Heritage Site because it boasts an astonishing fossil record of marine life from that time. Attracted to an incredibly diverse and well-preserved set of fossils, Swiss and Italian paleontologists have been excavating the mountain since 1850. Synthesizing and interpreting over a century of discoveries through a critical twenty-first century lens, paleontologist Olivier Rieppel tells for the first time the complete story of the fish and marine reptiles who made that long-ago lagoon their home. Through careful analysis and vividly rendered recreations, he offers memorable glimpses of not only what Thalattosaurs, Protorosaurs, Ichthyosaurs, Pachypleurosaurs, and other marine life looked like but how they moved and lived in the lagoon. An invaluable resource for specialists and accessible to all, this book is essential to all who are fascinated with ancient marine life.