This work represents an exhaustive review of one of the most important late Cenozoic radiations of Australian marsupials: the short-faced, or sthenurine kangaroos. Sthenurines originated in the Miocene, diversified in the Pliocene, and radiated in the Quaternary to become one of Australia's most conspicuous mammal groups, the only lineage of browsing marsupials comparable in diversity to the browsing artiodactyl guilds of other continents. The culmination of 12 years' research, the monograph details the taxonomy of the sthenurines, redescribing each of the six genera (two new) and 26 species (four new), and is amply illustrated with line drawings and more than 100 pages of plates. It presents the first cladistic analysis of sthenurines, and by synthesizing systematic, functional morphological, biochronologic and zoogeographic data, considers the major directions of adaptive change within the group, and the major environmental factors that drove their evolution. It is one of the most comprehensive studies of an extinct marsupial lineage ever made, and should be an essential reference for students of Australian late Cenozoic vertebrates, marsupial evolution, environmental change and Pleistocene extinctions.