The brothers then join Marion and they travel with a convoy on a Brachiosaurus to leave the village. The disturbance is soon quelled by a girl, who turns out to be Marion Waldo, revealing the source of the trouble to be a toothache. All of a sudden, a commotion occurs a rampaging Ankylosaurus is on the loose. Emerging from the smoke, is a man named Cyrus Crabb who leads the duo to a nearby village. As they examine what appears to be an ancient fossil structure, a sudden explosion occurs and destroys it. They soon discover that they are on the shore of a large uncharted island. Conceding the loss, he surfaces with David in the turbulent waters. When Karl goes back to rescue his father, he gets pushed away by the latter.
Karl and David both manage to get free and swim out of the sinking plane.
They encounter a severe thunderstorm the father wakes back up and manages to take control of the plane, but to no avail as it crashes into the ocean. Karl eventually takes over the controls as his father falls asleep. The film opens with a lady writing a letter to who seems to be a future daughter.The scene cuts to two brothers, Karl and David Scott along with their father boarding a plane, albeit to David's reluctance to go.The synopsis below may give away important plot points. The boys also learn that the incredibly powerful Sunstones, which serve as Dinotopia's only real power source but also represent the only thing that's keeping the carnivores away, are failing all over the island and only the forbidden ancient ruins of underwater dino temple may hold the key to Dinotopia's salvation. However, Cyrus approaches Karl claiming that a way out does exist but only if he gets him the necessary artifacts to chart the course out of there. While rebellious Karl plans to leave the island no matter what and find out what happened to their father, David is much more open to the idea of joining the Dinotopian society but rather disagrees with their decision to have him join the skybax riders, a unit of elite Pteranodon fliers that represent Dinotopia's main defense force and are led by the no-nonsense air commander Oonu. However, once the boys' learn that there actually is no way off the island because of the underwater reefs and storms that surround it, their individualistic personalities quickly clash with the more collectivist mindset of the islanders. A young, friendly, overly enthusiastic, English-speaking dino-scholar and troodon named Zipeau also befriends the two and eagerly agrees to welcome them into his own home until they can find their place in this amazing society, mostly resembling a highly advances version of Europe's medieval civilization. She gladly agrees to show the boys around and introduce them to Dinotopia's peoples and culture. The boys travel to the island's capital, where they meet Mayor Waldo and his disciplined, orderly, caring and quite lovely scholarly daughter, Marion, who along with the senate helps her father and her mother, Matriarch Rosemary, run the island in peace, love and understanding. He informs them that the island is called Dinotopia as both humans, who have reached spiritual, philosophical and intellectual enlightenment here a long time ago, and dinosaurs, who somehow survived here and evolved into sentient talking dinos with human intelligence, live there together in utopian pacifist harmony, save for the carnivores. The two manage to swim safely to shore where they meet Cyrus, the local misanthropic pariah who holds a serious grudge against the islanders. Trapped in the sinking plane wreck, the father orders the boys to abandon him and save themselves. The plane gets caught in a storm and crash-lands near an uncharted island. Half-brothers Karl, a born rebel, and David, the more curious and scholarly of the two young men, are flying a small airplane over the ocean with their rich father. After a plane crash, two opposing half-brothers find themselves on an amazing lost island where enlightened pacifist humans and intelligent talking dinosaurs have created a utopian medieval society.