Many would argue that the only nonhominid species that stir the hearts of palaeoanthropologists are those that have the potential to shed light on one or more aspects of human evolution. Species of Theropithecus enjoy this distinction and in some of the chapters of this book the parallels between hominid and theropith evolution are explored in detail. Perhaps more importantly, though, in this book we celebrate Theropithecus as an unsung hero of primate evolution in its own right. The study of the evolutionary biology of Theropithecus species has forced us to confront a series of difficult and controversial questions ranging from the nature of species and speeiation events through to the nature of events precipitating extinction.

This book is divided into four major sections and two appendices. The first two sections deal with specific and general aspects of the evolutionary history of Theropithecus, the third with aspects of the anatomy of the genus, and the fourth with the behaviour and ecology of extinct and extant Theropithecus species. The first appendix contains a partial catalogue of fossil specimens of Theropithecus and the second appendix comprises a report on the conservation of the sole extant species of the genus, T. gelada.

With two exceptions, all the papers that were originally presented at the 1990 Cambridge, UK, conference, ‘Theropithecus as a Case-Study in Primate Evolutionary Biology’ have been developed into chapters for this book. One of the two exceptions was Cliff Jolly's contribution in which the biology of the once species-rich Theropithecus was examined through the lens of the biology of the now species-rich Papio and the entirety of the Tribe Papionini.