United States of America.

Introductory intertitles read: "A hundred million years ago, the earth was dominated by gigantic reptiles, called dinosaurs." and "Strangest of all was the spine-backed Stegosaurus, and Mr Barnum Brown, Curator of the American Museum of Natural History, describes the pictures which follow."

Various shots of staff of the Museum assembling the bones of a Stegosaurus. They are presumably putting the bones together to display in the museum. The dinosaur was found in Wyoming, in the famous "bone cabin quarry" (?). Narrator tells us all about the Stegosaurus as he is constructed.

A painted backdrop is used to represent the vegetation of the Stegosaurus' habitat and the assembled bones are seen on a revolving platform. Barnum Brown recites a poem about the Stegosaurus which was written when it was thought that the Stegosaurus had two brains. Joke in the poem about about how one of the brains was in the dinosaur's bottom!