Realistic illustrations lend eye-catching glamour to the captionlike text . . . Make room for this sure-to-be-popular work.
—School Library Journal

O'Brien writes clearly about sabertooths as well as other prehistoric animals. The book's main strength, though, is its excellent artwork, which portrays dramatic scenes and quiet studies of the animals with equal skill and attention to detail.
— Booklist

Selected as an
Outstanding Science Trade Book for Students K-12
by the National Science Teachers Association and the Children’s Book Council.