The year is 3017. Before Aero-cars or space-rockets, humans or dinosaurs; before our planet was home to any form of breathing organism, a race more powerful than you can imagine watched over from a planet known as Prehistoria. The Menosaurs, as they are known, first discovered Planet Earth which they called Mordex. To them it was the richest planet beyond their solar system, beyond their galaxy. Why? Earth was the greatest known source of an invaluable rock named Grandidierite, known to them as Astronomite. Half-dinosaur half-human themselves, the Menosaurs took Planet Earth as their own. Here, over two-hundred-and-thirty million years ago, they created dinosaurs in their own image, used the Earth as their harvest grounds, wanting to evolve symbiotically with their surroundings. But they weren't the only race among the undiscovered solar-systems that wanted ownership of our planet. The Mantoids, sworn enemy to the Menosaurs, had their beady eyes on the same prize. Back on Earth, Rex, a technologically-adapted fourteen-year-old boy, half-tech half-human, and his rather paranoid furry yeti-droid care-taker, Rion, find Tarock the young Menosaur whose asteroid egg-capsule crashes into Earth near their home, on route to Prehistoria. Unfortunately, the U.S. Marines have also been alerted to the alien capsule's arrival, and they're not about to let this 'thing' walk free.