The early Mesozoic period was a critical period in the evolution of life on land when most of today's major groups of terrestrial vertebrates arose and dinosaurs and pterosaurs rose to prominence. In recent years this period has received a great deal of attention from palaeontologists, and it is now felt that the small vertebrates which lived in the shadows of the first dinosaurs tell us a great deal about the evolution of modern terrestrial ecosystems. This book is the first attempt to collate all the information on the small vertebrates and features contributions by experts with international reputations in their fields. There are chapters on the taxonomy and phylogeny of the key vertebrate groups, followed by a section dealing with the most significant fossiliferous assemblages worldwide. The final section looks at how faunal turnover at this time is measured and examines the possibility of mass extinctions.