As the coexisintg bumblebeetle shows, an essential condition for life in the Rainshadow Desert is the ability to range over large areas looking for food. This requirement has been solved in different ways by different animals, but perhaps the most surprising, when we consider its ancestry, is the desert hopper.
During sunset, there will be movement in the sand and thick desert soil. Desert hoppers will be pushing their way to the surface. First to emerge is the large snail's shell. Then the rest of the creature appears, slowly pushing itself from the sand and soil with its muscular foot. Finally, it raises itself, balancing on the tip of the foot, its body forming an elegant, vertical S-shape.
The tip of the foot has three toe-like projections, which spread its owner's weight across the sand. Instead of being mounted on stalks, this gastropod's eyes are in circular turrets, like those of a chameleon. When completely emerging from the ground, it lifts its shell clear off the ground and sways for a moment. Then the snail jumps away.
Throughout their evolutionary history, land snails have been slow-moving, rather passive animals. They have always preferred moist places where the plants upon which they feed are abundant. Crawling slowly on a strong, muscular, fleshy foot lubricated by a trail of slime, the previous land snails rasped food from plants using their radulae. In the chocked and unyielding habitat of the Rainshadow Desert, the desert hopper has evolved to become a successful herbivore among the region's sparse, tough plants.
The desert hopper is one foot (30 centimeters) tall. When withdrawn into its 8-inch (20-centimeter) shell, it has few enemies. It does not secrete a trail of slime - a waste of water in a desert habitat. The soft skin of its ancestor has evolved into horny, interlocking scales, forming a tough, lizard-like skin that locks in essential moisture.
Most remarkable of all is the desert hopper's muscular foot. The foot is a jumping organ. It carries the snail across the desert at a speed similar to that of a human jogging. In previous times, a species of marine cone snail could use its muscular foot to hop away from predators. In 200 million AD, this has developed into a method of moving swiftly on land. The jumping action also works a bellows mechanism within the shell of the desert hopper, allowing air to be pumped in and out of the lungs and providing sufficient oxygen for its active lifestyle.
The desert hopper's diet consists of tough, fibrous vegetation. The muscular, denticle-covered mouthparts (including the radula) of its ancestor have evolved into a rod-like structure with a denticled drill at the end. This can pierce the waterproof cuticle of a plant to reach the pulp inside. The desert hopper's shell and thick skin provide an efficient defense against most plant thorns and spines. Like many desert animals, the hopper does not drink that much. It obtains all its water from food, and is perfectly adapted to keep all that moisture within its body.
Despite being a voracious plant-eater, the desert hopper itself is food for a plant: the death-bottle.