Preparations for Visitors Day in Room 101 come to a sudden halt when Ms. Frizzle receives an invitation to a dinosaur dig. With a twist of a dial, the Magic School Bus becomes a time machine hurtling through prehistory, stopping at various points in the Mesozoic Era so the class can observe flora and fauna, shoot a video, make smart remarks, and generate the usual blizzard of written reports. Readers may be confused to read on one page that reptiles are cold-blooded and that dinosaurs were a kind of a reptile, and on the next that some may have been warm-blooded; otherwise, Cole mixes up-to-date facts and general statements with virtuoso skill, stirring in plenty of jokes, small subplots, and flights of fancy. One gruesome scene aside, Degen's full-color illustrations enhance both the humor and the information, featuring maps, charts, actual-size drawings of fossil teeth, plenty of dinos in action, and Ms. Frizzle's famous, ever-startling wardrobe. Climb aboard-there's never a dull moment with "the Friz" at the wheel!-John Peters, New York Public Library Copyright 1994 Reed Business Information, Inc.