Platus was a planet in the Vegetarian Sector that was controlled by the plateosaurus, a peaceable breed of dinosaur. The plateosaurus decided to return to Earth but were decimated by a cosmic storm in space and the survivors limped home, only to find that it had been conquered by an invasion force of T. rexes. They attempted to fight the carnivores, but lost the battle. The DSS was founded to help the plateosaurus and eventually defeated the T. rexes, but Platus had been almost destroyed and was uninhabitable, so the few remaining plateosaurus became wanderers.