Daniel J. Wiley

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.

Littlefoot befriends with a mysterious, fun-loving dolphin-like creature named Mo, who is trapped in "new water" caused by heavy rain. The gang then goes on an adventure to the "big water" to bring Mo home.

As the Great Day of the Flyers nears, the Great Valley's flying youngsters are eager to participate in the annual exhibition to show off their skills. Everyone, that is, except free-spirited pterodactyl Petrie, whose individualism causes problems when it comes to staying in formation. Enter his dinosaur pals Littlefoot, Cera, Spike and Ducky, who encourage Petrie to embrace his uniqueness.