Focusing on the cretaceous period, this book starts with a brief introduction of how the land masses on our planet shifted and a descriptive timeline of each period from the Precambrian to Quaternary (now).  The tone is conversational but includes a great variety of facts and details readers seek.  There are many logical suppositions about how dinosaurs lived, ate, and protected themselves.  Illustrations are full-color, realistic scenes.  Double-page spreads include 2 – 3 text boxes, a location/length box, and a “Did You Know?” box.  The end of the cretaceous period is explained by the asteroid impact, most likely near present-day Mexico.  This well-written, informative book is one of four in the series.  Each could stand alone.  Other titles are, The Dawn of Planet Earth, Dinosaurs Rule, and The Rise of Mammals.  The complete set would be great addition to any library.  A final “Did You Know?” page with accompanying pronunciation is at the back of the book with an index and short comments about the author and illustrator.