Millions of years before the Age of Dinosaurs, an environmental cataclysm annihilated 90 percent of all plant and animal life on the planet. In this lost world that was swept away 250 million years ago, the ferocious lizard-like Gorgon was the T. rex of its day. In this remarkable journey of discovery deep into Earth's history, Peter D. Ward, one of the world's most recognized authorities on mass extinctions, examines the strange and mysterious fate of this little-known prehistoric animal and its contemporaries--the ancestors of the turtle, the crocodile, the lizard, and eventually the dinosaur. Based on more than a decade's research in South Africa's Karoo Desert, Ward's groundbreaking work offers provocative theories on the mass extinctions of the past and confronts the startling implications they hold for humanity's future on the planet.