Renowned paleontologist and New York Times bestselling author of The Rise and Fall of the Dinosaurs, Steve Brusatte, charts the extraordinary story of the dinosaurs' successor: mammals, which emerged from the shadows to rule the Earth. Brusatte also brings alive the lost worlds mammals inhabited over the past 66 million years, from ice ages to volcanic cataclysms. Entwined in this story is the detective work he and other scientists have done to piece together our understanding using fossil clues and cutting-edge technology.