When Flint returns to the island to help clean up after the disastrous food storm, he discovers his machine now creates mutant food beasts, from which he and his friends must save the island from.

Dinosaur tells the story of Aladar, an iguanodon who is separated from his own kind and raised by a clan of lemurs. When a meteor shower destroys their home, Aladar and his family follow a herd of dinosaurs heading for the safety of the "nesting grounds." Together they must stand strong amidst food and water shortages, the threat of Carnotaur attacks, and Aladar's run-ins with the herd's stubborn leader, Kron.