Littlefoot’s grandfather one night tells the protagonist children a story about “The Lone Dinosaur”, a legendary longneck who once protected the Great Valley from the most ferocious sharptooth ever to live. A fight ensued, which led to the Sharptooth’s death. However, the sharptooth left “The Lone Dinosaur” with a scar slashed across his right eye. Soon after the battle, a huge monolith that resembled a proud sauropod, having life-sized tyrannosaur teeth arranged around his neck, came out of the ground during an earthquake. The dinosaurs called it “Saurus Rock”. The legend also states that if anyone damages the monolith, bad luck would descend upon the valley.