1997 32¢ Opisthias
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.)
More than 200 million years ago during the Triassic Period, a diverse group of lizards appeared which continued to develop throughout the Jurassic Period. In time, an offshoot of these prehistoric reptiles went on to become the true lizards and snakes we know today.
The Opisthias however, remained virtually unchanged. Its modern-day relative, the tuatara, is the only living link to this ancient group of reptiles. Considered to be a close relative of the extinct dinosaurs, this lizard-like reptile is literally a living fossil.
Our world has changed drastically since the time of the dinosaurs. During the early Triassic Period, the continents we know today once formed a giant land mass. Dinosaurs and other reptiles, including the Opisthias, were able to wander freely over land connections between continents. Today however, the tuatara can only be found on a few islands off the coast of New Zealand.
Primitive-looking creatures with scaly, greenish-gray skin, tuataras grow slowly and do not mate until they are about 20 years old. However, they also have an extremely long life span – some are known to have lived for as long as 77 years. Rats introduced to the islands are a serious threat. This unique reptile, which survived for millions of years, may now be in danger of extinction.