The Mesozoic Era is often referred to as the Age of Dinosaurs, for during its 150 million years these terrible lizards dominated the earth. While the gigantic reptiles that enthrall today's schoolchildren - the tyrannosaurs, triceratops, and stegosaurus - lumbered through the subtropical landscape, the pterosaurs ruled the skies, and the ichthyosaurs swam the seas. Perhaps the greatest fascination Mesozoic reptiles hold for us is their amazing size. How, for example, did Brachiosuarus carry a weight thirteen times that of an African elephant? And how did the largest of pterosaurs, with the wingspan of an executive jet, manage to become airborne? The smaller dinosaurs present their own puzzles: modern reptiles, being cold-blooded, rely on the use for warmth and are relatively inactive at night. They also lack stamina and are unable to sustain top running speeds for long periods. Some of their ancestors, such as the kangaroo-sized Dromaeosaurus, had the well-developed legs of a natural runner. Could they have been warm-blooded and able to continue their activities at night, as mammals do? Given that the Mesozoic Era ended 65 million years ago, how can we possibly solve these mysteries? The best approach to understanding extinct animals, argues Christopher McGowan, is to study living ones. What, for example, can giraffe physiology tell us about the thirty-foot neck of a brachiosaur? To give his analysis even more breadth, McGowan draws on basic concepts f science and engineering to explain curiosities such as the similarities between the aerodynamics of pteranodons and Spitfires. This book is replete with topics of broad interest: warm-bloodedness, running capabilities, intellect, the mechanical properties of bone, gigantism, bird-dinosaur relationships, skeletal design, fossils and preservation, and extinction. Yet, the author reminds us, we by no means have all the answers. We may build lifelike models of dinosaurs for museum displays, but we do not really know what colour they were or what sounds they made.