Harry and the Dinosaurs at the Museum by Ian Whybrow, Adrian Reynolds (Illus)

Harry's sister, Sam, is studying the Romans, so Mum and Nan take them both to the museum. Sam starts working on her project, but the dinosaurs start to get bored. So Harry teaches them some tricks, like climbing, sliding, and playing hide-and-seek. But soon they're having so much fun that they get lost! Will Nan know where to find them?