Lacing her narrative with deliciously mouth-filling names—Pachyrhinosaurus, Fulgotherum, Saurornitholestes (go ahead, try them out)—Arnold tallies recent fossil discoveries inside or close to the Arctic and Antarctic Circles proving that dinosaurs weren’t just tropical animals but could adapt to cold climates and long nights too. Moving region by region around the globe, the narrative provides brief descriptions of fossil finds in Alaska, Siberia, Canada, Antarctica, Australia, New Zealand and Patagonia, along with hypotheses explaining diet and possible migratory habits that enabled them to survive. Caple offers only conventional portraits of big, toothy creatures patterned in subdued colors and posing against generic, sometimes snowy backgrounds, and the author’s title has only the most tenuous connection to her actual subject. However, Arnold has found a topic that hasn’t been treated in such detail elsewhere, making it a sure draw, therefore, for confirmed young dino-fans. (museum list, index) (Nonfiction. 9-11)