School Library Journal: Gr 3-5- A look at saber-toothed cats, with an emphasis on Smilodon , which perished in the thousands in the La Brea Tar Pits, leaving their blackened bones to be discovered 10,000 years later. O'Brien traces the feline family back to early Proailurus (30 to 20 million years ago), mentions a number of species, and includes some non-feline predators with saberlike canines. Realistic watercolor and gouache illustrations lend eye-catching glamour to the captionlike text, showing Smilodon 's skeletal makeup and making life-size comparisons of teeth from a sabertooth, a modern tiger, and a modern human. Other contemporary predators are illustrated as well, along with a picture gallery of possible prey. While some recent research seems to indicate a measure of dental "fragility" limiting bite pressure, O'Brien opts for the cat's "huge teeth" as "perfect for biting through the thick, hairy hide of big beasts, such as mammoths and buffalo." Even if you already own Barbara Hehner's dramatic Ice Age Sabertooth: The Most Ferocious Cat That Ever Lived (Crown, 2002), you might want to make room for this sure-to-be-popular work.