Despite intense interest in this biologically diverse and ecologically important region, the mammals of South America are still not well known. This volume provides a survey and synthesis of knowledge of the more than 650 species of land and marine mammals found in Ecuador, Peru, Bolivia, and Brazil. Chapters present not only taxonomic information but also ecological and behavioural characteristics, conservation status, and distribution maps for most species. Numerous illustrations are provided to assist in field and laboratory identification, including colour and black-and-white plates by Fiona Reid. New to this volume are chapters contributed by experts on the mammalian fossil record of this region and on its biodiversity and biogeography.