Though they are an extinct species, dinosaurs still live and fascinate the minds of many a scientist and researcher world-over. Dinosaurs are members of a larger group of reptiles called the Archosauria. The essays in this book seek to provide readers with a detailed knowledge of the first dinosaurs that roamed the earth, different carnivorous dinosaur predators that belonged to groups called theropods and dinosaur behavior peculiarities. The book is a complete collection of information on dinosaurs, the periods in which they existed and the reasons why they vanished from the face of the earth.