Nobita visits a dinosaur exhibition with his friend. In a fossil excavation experience there, he vows to his friends that he will discover a dinosaur and says that he will eat monkey nuts with his eyes if he fails. As he leaves the excavation experience, he trips over a rock and suspects that he has found the fossil of an egg. He goes home and convinces Doraemon to use the "time wrapping cloth" on the fossil egg, and twin feathered dinosaurs emerged.