Piecing together the events of lost civilizations has always fascinated the world. Read about King Tut, whose hidden tomb and its treasures were uncovered in 1922, in Egypt's Valley of the Kings; the Mayan calendar, created more than 1,000 years ago, perhaps to predict the end of the world; and the events that caused Earth's five great mass extinctions, killing off 98 percent of all species that ever lived. Features include detailed maps, educational front/back matter, full-color illustrations, full-color photographs, glossary of key words, index, informative sidebars, primary-source text, sources for further research, suggested websites, and table of contents. Downloadable Teacher Notes available.