First appearing about 40 million years ago in North America, rhinoceroses diversified into an incredible array of taxa, with a variety of ecologies that don't resemble any of the five living species. They ranged from delicate long-legged dog-sized forms, to huge hippo-like forms that apparently lived in rivers and lakes. Including a complete systematic review, and discussions of biogeography, evolution and paleoecology, this book summarizes our current knowledge of North American rhinos and constitutes the most complete reference available.