During the age of the dinosaurs, a massive famine forces several herds of dinosaurs to seek an oasis known as the Great Valley. Among these, a mother in a diminished "longneck" herd gives birth to a single baby, named Littlefoot. Years later, Littlefoot encounters Cera, a "three-horn", until her father intervenes and tells her that three-horns don't play with longnecks, whereupon Littlefoot's mother describes other kinds of dinosaurs, who only associate with their own species. That night, as Littlefoot follows a "hopper", he encounters Cera again, and they play together briefly until a large "Sharptooth" attacks them. Littlefoot's mother comes to their rescue, but receives fatal injuries in the process. An earthquake swallows up the Sharptooth and divides Littlefoot, Cera, and other dinosaurs from their herds; several die in the process, including Littlefoot's mother, who first gives her son some words of advice about finding the Great Valley. Confused and in grief, Littlefoot meets an old "clubtail" named Rooter, who consoles him. He is then guided by his mother's voice telling him to follow the sun to the Great Valley and pass several landmarks, such as a rock formation that resembles a Longneck and the "Mountains that Burn".