This extraordinary encyclopedia tells the story of life on Earth - from one-celled sea creatures to armored swimmers, from eight-foot-wide spiders to dinosaurs of every size and shape, from woolly mammoths to saber-toothed tigers, and finally to recent animals, including the dodo and the passenger pigeon. These are not animals that we can see today, in zoos or in the wild. Over the past four billion years, they have lived on this planet and disappeared, never to return.

It's all here - the animals themselves, the changes that caused their extinction, and the modern discoveries that are only now revealing their lost worlds. The book tells the story in order, from four billion years ago up to the present. Each chapter explains what happened in that period and which animals lived then. Major extinction events are discussed and illustrated, and each chapter ends with a gallery of animals that became extinct during that time.