Synopsis for
The Land Before Time X: The Great Longneck Migration (2003) (V) More at IMDbPro »

Plagued by mysterious dreams, Littlefoot, his grandparents and all the other Longnecks depart the Great Valley, joining up with other Longneck herds as they travel to a single location; with Cera, Petrie, Spike, and Ducky (Littlefoot's friends) following the herds to an enormous crater, which they believe is the culmination of their journey. Littlefoot learns that long ago, that the Bright Circle (sun) was going to fall. However, a number of Longnecks came together to this very spot and raised up their necks, lifting the Circle back to where it had been. According to this creation myth, this stretching of their necks is how the Longnecks got their long necks. History is about to repeat itself, and so the Longnecks have returned to the crater in order to save the sun once more.

However, another surprise is in store, as Littlefoot meets his father, Bron (Kiefer Sutherland), for the first time in his whole life. However, Bron isn't alone. Since parting from his now deceased wife (a song from The Land Before Time IV: Journey Through the Mists reveals that the concept of marriage does exist in The Land Before Time universe), he has become guardian to another young Brachiosaurus, Shorty, who becomes jealous of Littlefoot since Bron is spending more time with him. One dawn, Shorty tries to run away, but Littlefoot stops him and convinces him to rejoin the migration, he even goes as far as to suggest they become brothers. At this point, Littlefoot's friends arrive. Soon after, following a Sharptooth attack there is a furious battle. Bron, Pat, Grandpa and Grandma defeat the sharpteeth.

Meanwhile the time comes for the Longnecks to save the sun again. Then they succeed and save the world. (However, what happened was, in fact, a solar eclipse; the Longnecks merely thought the sun was falling.)

With their mission completed, the herds depart. Knowing their true places, Littlefoot tells Bron to take care of Shorty, and returns to the Valley with his friends and grandparents.