When the farmer's away, all the animals play, and sing, and dance. Eventually, though, someone has to step in and run things, a responsibility that ends up going to Otis, a carefree cow.
Littlefoot and his pals set off in search of a "stone of cold fire" that fell from the night sky. Since he's the only one who has seen it though, nobody really believes him. Petrie's uncle Pterano offers support only because he thinks the stone has secret powers and wants it for himself but conceals this from the rest. The young dinos must figure out the truth, before Pterano gets the power.
When the dinosaur families get trapped in a valley by an ice storm, one family of "spike tail" dinosaurs volunteers to leave since they consume more food than the others. Meanwhile, the young dinos and a new adult dinosaur named Mr. Thicknose, head out to bring back their friend Spike, who has left his friends to be with members of his own species.
