Book excerpt: Follow Ackerley the Acanthostega through the Cretaceous period, 145 to 66 million years ago, when the mightiest dinosaurs stalked the planet. Watch them seek prey, battle enemies, and finally face mass extinction. Discover the facts, fossils, and fun science behind the fiercest carnivores of this time period. Learn about the rise of the raptors, the largest dinosaurs, and the great extinction. This third part of the exciting story of life on Earth unfolds through amazing lifelike illustrations and fascinating diagrams, all narrated by a friendly prehistoric guide.