Dinosaur Atlas

Dino Don's Dinosaur World Welcome to the world of dinosaurs! Actually, worlds would be more accurate. Dinosaurs ruled the Earth for 150 million years, and during that time, the world changed from a single warm land mass into a series of continents that closely resemble the modern Earth. Despite these dramatic changes -- changes that affected plant life, animal life and even the air -- dinosaurs managed to thrive. How? Dinosaurs were remarkable creatures -- so remarkable that only a grown-up could fail to wonder at their greatness. As the world around them changed, the dinosaurs changed too. Over millions of years, they evolved into bigger, stranger and more diverse creatures in order to adapt to their surroundings. This atlas is your guide to the amazing dinosaurs that walked, ate, fought and died in these long gone worlds. In the pages that follow, you'll learn how the world changed and how the dinosaurs changed with it. You'll learn about more than 50 types of dinosaurs -- their names, food preferences, habits and enemies. You'll even learn how dinosaurs have helped paleontologists and other scientists understand more about the Earth's history. So get going! Have a great trip, and watch out for dinosaurs! "Dino" Don Lessem -- The World Before Dinosaurs There wasn't always life of Earth. Five billion years ago, when the Earth was formed, not a single living thing walked the planet. Life began as a single cell -- that kind that's only visible under a microscope -- and took billions of years to develop into large animals. We know that by about 600 million years ago, life had still not appeared on land. Although there were animals in the sea, they never grew larger than the size of your hand. It wasn't until about 300 million years ago that the first small amphibians walked ashore. Plants, insects and animals gradually began to conquer the land. As they did, the look of the Earth started to change. About 250 million years ago, the Earth's Middle Age -- or Mesozoic Age -- began. This was the age of the dinosaurs, although it began without the dinosaurs themselves! In the early days of the Mesozoic, a period known as the Triassic, big reptiles called archosaurs (see below) ruled the land. Some, like the coffee-table sized aetosaurs were land loving; others, like the seal-sized nothosaurs were water-dwelling. It was into this world that the dinosaurs first walked. Saurosuchus(SORE-oh-SOOK-us) NAME MEANS: "reptile crocodile" GROUP: Archosaurian reptiles SIZE: 20 feet (6 m) long PLACE: Worldwide DIET: meat Archosaurs -- the "ruling reptiles" -- came in many odd shapes and sizes, including dinosaurs. Before dinosaurs, the most common archosaurs may have been the pig-like rhynchosaur, a small plant-eater with thick tusks that were probably used to dig for roots and other plants. Another reptile, Saurosuchus, was king of the pre-dinosaurian world. This killer crocodilian grew to lengths of more than 20 feet (6 m)!Lessem, Don is the author of 'Dinosaur Atlas' with ISBN 9781552978306 and ISBN 1552978303.