Dinosaurs of the Air: The Evolution and Loss of Flight in Dinosaurs and Birds presents the most recent work of renowned evolutionary scientist and dinosaur illustrator Gregory Paul. Dinosaurs of the Air synthesizes the growing body of evidence which suggests that modern-day birds have evolved from theropod dinosaurs of prehistoric times. Paul argues provocatively for the idea that the ancestor-descendant relationship between the dinosaurs and birds can on occasion be reversed, and that many dinosaurs were secondarily flightless descendants of creatures we would regard as birds. Controversial and comprehensive, Dinosaurs of the Air also offers new, firsthand interpretations of major fossils; a balanced, rewarding discussion of the ways we think flight may have evolved (comparing "ground up" and "trees down" scenarios); a close look at the famous urvogel Archaeopteryx, discussing what it can and cannot tell us about bird origins; and in-depth analyses of bird and theropod phylogenetics. Full of rich detail for the specialist but accessible to the intelligent lay reader, the book includes the author's own stunning illustrations and a technical appendix which provides information, for example, on body mass/wing dimension relationships and avian/dinosaurian metabolics.