Until a few thousand years ago, creatures-\"megafauna\"-that could have been from a sci-fi thriller roamed the earth. With a handful of exceptions, all are now gone. Ross MacPhee explores the question of what caused the disappearance of these prehistoric behemoths, examining the extinction theories, weighing the evidence and presenting his conclusions. He comments on how past extinctions can shed light on future losses and on the possibility of bringing back extinct species through genetic engineering. Gorgeous four-colour illustrations bring these megabeasts back to life in vivid detail. 78 color illustrations