As the time and reign of the dinosaurs draws to a close, it is time for some great changes to happen on the world of Equus. The mighty reptiles of the distant world begin to appear all around Equestria and start their new lives there. Now the pony folk, and slowly every other country in the world, must learn how to co-exist with these mighty creatures. Some will accept them as friends, while others will reject them as monsters.

Meanwhile, an ancient evil that's been dormant since the All Mother created the world, begins to awaken, and with it it's desire for revenge. Now, not only must the pony folk gather their courage for this great battle, but the mighty dinosaurs must ban together as well to defeat this great evil. They must forfill their destinies as the Guardians of Equestria.