The film follows a group of young ornithodirans (four dinosaurs and a pterosaur) by the names of Littlefoot (Apatosaurus), Cera (Triceratops), Ducky (Saurolophus), Petrie (Pteranodon), and Spike (Stegosaurus) in their search for an oasis known as the Great Valley.

Charles R. Knight (1874-1953) was an American artist best known for his influential paintings of dinosaurs and other prehistoric animals. Knight's most famous work depicts the classic confrontation between Triceratops and its deadly adversary Tyrannosaurus rex. Paleontologist Bob Bakker said of this prehistoric rivalry, "No matchup between predator and prey has ever been more dramatic. It's somehow fitting that those two massive antagonists lived out their co-evolutionary belligerence through the last days of the last epoch of the Age of Dinosaurs."