Wolves and tigers and bears, oh my! For readers who have always wanted to know the differences between mastodons and woolly mammoths, these are the books for them. Some favorites such as the saber-toothed tiger and American mastodon are included, but lesser-known gigantic mammals are also featured: the giant beaver, dire wolves. A mix of illustrations, photographs, and computer-generated imagery is sprinkled between the short sections of text. Fossils are, of course included, but the really fun sections are the size comparisons to other animals of the past and present. VERDICT These titles address historic climate change and extinction in a captivating way for emerging readers. A great choice for school libraries to add to their animal and ecosystem collections.