Aliki's return visit to the dinosaurs doesn't add to the information already available to these prehistoric giants' youngest fans, but the author/artist's sprightly presentation gives some new life to the old bones. Her talking pictures extend the text and keep her audience on its toes: ""I recognize Iguanadon by its horn thumbs,"" says a museum visitor, directing our attention. Pages later, two museum workers remark, ""When they first found Iguanadon, they thought its thumbs belonged on its nose!"" ""Those early scientists had some job!"" Another specialist, chipping away, says, ""I can tell from these many fiat teeth that this was a plant-eater."" And just for fun, we have a photographer on a dig telling the heap of bones, ""Don't move!"" (For her next visit, though, Aliki might take a hint from the painstaking scientists she profiles: The protoceratops eggs, discovered much later, don't belong on display in her 1800s museum scene.) Sprightly.