The story starts on Earth 65 million years prior, with people and dinosaurs living next to each other. It is here we meet Arlo (voiced by Raymond Ochoa) and his family. They are a gathering of green brontosauruses, who develop corn and live cheerfully. At some point, Arlo’s dad (voiced by Jeffrey Wright) accuses him of catching a secretive animal who has been taking their corn. It turns out this “animal” is really a human named Spot (voiced by Jack Bright). Before long, a misfortune strikes and Arlo is isolated from his family. He is lost, alone, and frantic for help, however Spot turns into a far-fetched partner. They wind up setting out on a wild experience through the dinosaur world to track down Arlo’s family.