From the author of the acclaimed Age of Birds this is an authoritative volume, and profusely illustrated discussion of the origin of birds and of avian flight which draws on fossil evidence and studies of the structure and biochemistry of living birds. Feduccia begins with an overview of bird evolution, giving his opinions about one of the most controversial problems in invertebrate palaeontology - whether birds evolved directly from bipedal, terrestrial dinosaurs or from the precursors of dinosaurs, small arboreal thecodonts perhaps. On the way he provides information about the origin of avian flight and feathers, discusses the most dramatic discoveries in avian palaeontology in the past few decades - the `opposite birds', the dominant landbirds of the Mesozoic - and argues that the evolution of birds followed a similar pattern to that of mammals, an explosive evolution lasting only 5-10 million years. The second half is concerned with the modern evolution of birds, and a comprehensive summary is provided of the evolution of the raptors, the rise of the landbirds, and the evolution of flightlessness.