Five young warriors from an ancient civilization of Dinosaur-evolved Humans are awakened during the present day after 170 million years of suspended animation when their sworn enemy, Bandora the Witch, is inadvertently released from her magical container on Planet Nemesis by two astronauts. The five warriors, the Zyurangers, must summon the power of mechanical-looking deities known as Guardian Beasts, each modeled after a different prehistoric beast, in order to protect mankind from Bandora's evil forces. A sixth warrior, Burai the Dragon Ranger, later becomes involved with the conflict between the Zyurangers and Bandora's forces.