One of Our Dinosaurs Is Missing

In this 1975 comedy adventure film, a Queen's Messenger named Lord Southmere finds himself in a wild chase across London after being pursued by Chinese spies for possession of a microfilm containing the mysterious formula for Lotus X. He hides the film in the bones of a Brontosaurus skeleton at the Natural History Museum, but his captors soon discover it and set out to retrieve it, leading to a series of hilarious and action-packed events as the skeleton is pursued through the streets of London by nannies, steam lorries, and spies.