Unlike many stamp artists, illustrator James Gurney had no live models to pose for him; his subjects had all been dead for millions of years. However, the best-selling author of the Dinotopia series captured subtleties of texture and shadow by shining bright lights on plastic models, some of which are shown here. Gurney based the colors of each creature on the patterns of modern animals, and several prominent paleontologists served as consultants.

Originally titled “Masters of the Mesozoic,” The World of Dinosaurs began as one block of four stamps, but the project quickly expanded to show two scenes from prehistoric North America: Colorado during the Jurassic period, approximately 150 million years ago; and Montana during the Cretaceous period, around 75 million years ago.