1997 32¢ Camptosaurus
Issue Date: May 1, 1997
City: Grand Junction, CO
Printed By: Sterling Sommers for Ashton-Potter (USA) Ltd
Printing Method: Lithographed
Perforations: 11 x 11.1
The World of Dinosaurs sheet depicts two scenes - one from Colorado during the Jurassic period (about 150 million years ago) and one from Montana during the Cretaceous period (approximately 75 million years ago.)
The Earth changed mightily during the 150 million-year reign of the dinosaurs. In the early millenniums, our planet was warm and humid. Tropical and semi-tropical plants such as cycads, ferns, horsetails, and pine trees were the dominant vegetation through the Jurassic Period. But in the Late Jurassic, the covered seeds of flowering plants appeared. They became the dominant plant group during the Cretaceous Period and continue to be so today.
The plant-eating Camptosaurus appeared as the variety of vegetation was changing and increasing, and his body structure reflects this. Camptosaurus was a medium-sized dinosaur that varied in length from six to 20 feet. He was a relatively primitive biped with strong hind limbs and a heavy tail that supported his weight when he stood erect. Though capable of walking on all fours, he preferred to forage for his food while standing.
Camptosaurus had a long, massive skull. And like so many plant-eating dinosaurs, he had a beak-like upper jaw that was longer than his lower jaw. The horny beak was designed for pushing plant material into his mouth. From there, the broad, leaf-shaped teeth on the sides of his cheeks ground it up before he swallowed it.