The Land Before Time VI: The Secret of Saurus Rock (1998)

Plot
One night, Littlefoot's grandfather tells the children, the beginning of their world: in the Universe the smoke created the Milky Way Galaxy, and early life on Earth, even a legend about "The Lone Dinosaur", a legendary Longneck who protected the Great Valley from the most ferocious Sharptooth to ever live. During the fight, the Sharptooth was killed and the Lone Dinosaur suffered a scar across his right eye. Soon after the battle, a huge monolith resembling a sauropod with life-sized Sharptooth teeth arranged around his neck came out of the ground during an earthshake. The dinosaurs called it "Saurus Rock". The legend also states that if anyone damages the monolith, bad luck would descend upon the Valley.

The next day, while the children are playing, Littlefoot accidentally falls off a cliff and is saved by a mysterious Diplodocus named Doc. Littlefoot is intrigued by Doc, who is scarred across one eye and displays prior knowledge of the Great Valley's topography. This causes him to assume Doc is the Lone Dinosaur. He tells his friends this, narrating an apparently extemporaneous legend to support his assumption. Inspired, Cera's infant nieces, twins Dinah and Dana, go to Saurus Rock unnoticed. The next day, a worried Cera informs Littlefoot that Dinah and Dana are missing, and the group deduces where they are headed.

When Littlefoot and his friends finally reach Saurus Rock, they see Dinah and Dana on the top. As they climb up to rescue them, Dinah and Dana fall off the top and land on one of the stone teeth on the monolith that Cera is on, and it suddenly breaks off and crumbles upon landing on the ground nearly hitting Spike. Dinah and Dana start to cry. But Cera tells Dana and Dinah that it is not their fault that Saurus Rock was broken; but Littlefoot's. She says to Littlefoot that if he had not been talking about it and Doc (the Lone Dinosaur), then Dinah and Dana would not have run away in the first place. Dana and Dinah corrects her that it was she who told them to get lost due to what happened at the Bubbling Goo. Suddenly, an Allosaurus chases them. The children cross a gorge via a suspended log, but when the Sharptooth tries to follows them, the log breaks under its weight and it falls to its apparent death. On the way home, they are confronted by Cera's father; after Littlefoot tells Cera that the twins (Dinah and Dana) are back and says that Cera's father never knew that they ran away. Cera's father comes up and asks Cera if the twins really ran away ("Ran away? What do you mean Cera? Did the twins really run away?"). Cera says, "Sort of. But they didn't go far". Ducky tells Cera's father that Dinah and Dana went to Saurus Rock. Upon hearing that absurd comment from Ducky, he tells Cera that it was her job to watch the twins but failed. He scolds Cera for not properly caring for the twins. He says that he is very angry and disappointed and tells her to immediately march herself home. Then as Cera marches herself home, he continues with his talk on her that she still must be watched herself. That night, Littlefoot has a nightmare in which he falls off a tooth on Saurus Rock and the entire monolith collapses.

Over the next few days, incidents of bad luck plague the Valley. A tornado hits the valley, causing damage, but Cera saves the twins and Doc also saves Littlefoot. Dinah and Dana tell Cera's father of her courage for saving them, in which he tells his daughter that he is proud of her. Littlefoot's grandfather finds Doc with his grandson. Doc protected Littlefoot from the worst of the storm and Grandpa thanks him. The adults, however, blame Doc, as the misfortunes apparently occurred after his arrival, while Littlefoot blames himself and his friends, recalling the breaking of Saurus Rock. Eager to exonerate Doc, Littlefoot attempts to take one of the Sharptooth's teeth to replace the broken stone. In the process, he discovers the Allosaurus is still alive. After temporarily escaping the Allosaurus, Littlefoot is attacked by a Tyrannosaurus, with Grandpa intervening, having been led there by Littlefoot's friends. Soon, the Allosaurus returns and works together with the Tyrannosaurus to take down Grandpa Longneck and easily overpower him. However, Doc comes to the rescue. The sharpteeth charge through and run into the rock spire and fall down. Doc and Grandpa work together to pull down a category of rocks and bury the carnivores. One of the teeth from the Allosaurus falls out, and the children use it to repair Saurus Rock.

Doc departs, remarking that Littlefoot already has a hero on whom to depend on, referring to Grandpa. Littlefoot asks Grandpa if the bad luck will finally be over. They both agree that while there is no such thing as bad luck, there is also no harm in making sure. Littlefoot and Cera later build a legend of their own based on this new paradigm, portraying Grandpa Longneck as a hero and savior called "The Great Dinosaur".

Voice Cast

 * Kenneth Mars as Grandpa Longneck
 * Thomas Dekker as Littlefoot
 * Anndi McAfee as Cera
 * Aria Curzon as Ducky
 * Jeff Bennett as Petrie/Spike
 * Kris Kristofferson as Doc
 * Miriam Flynn as Grandma Longneck
 * John Ingle as Cera's father
 * Nancy Cartwright as Dana
 * Sandy Fox as Dinah
 * Danny Mann as Allosaurus

Songs
The songs are written by Michele Brourman and Amanda McBroom.
 * The Legend of the Lone Dinosaur - Littlefoot, Cera, Ducky, Petrie, Spike, Dinah and Dana (Thomas Dekker, Anndi McAfee, Aria Curzon and Jeff Bennett)
 * Bad Luck - Littlefoot, Cera, Ducky, Petrie and Spike (Thomas Dekker, Anndi McAfee, Aria Curzon and Jeff Bennett)
 * On Your Own - Littlefoot (Thomas Dekker)