Laurence Pringle's introduction to a high-interest topic for preschoolers is exemplary for its simple text which manages to convey basic information about dinosaurs and paleontology without talking down to his audience. Carol Heyer's realistic full-color acrylic paintings illustrate the text perfectly as she depicts scientists at work, several species of dinosaurs and, in one case, three possibilities scientists have suggested as to how plates fit onto the body of a Stegosaurus. (Ages 3-6)