Travel back in time to when the Earth was young-a boiling mass of liquid rock. Then trace how early life developed over billions of years, from the first tiny life-forms to the dinosaurs, and then to monstrous mammals as big as a bus. Find out how our human ancestors survived in a world so different from our own. Lists, charts and maps give summaries of prehistoric records and statistics. This book also contains of Internet Links to specially chosen websites, helping you to dog up more fascinating facts about the prehistoric world.