The Land Before Time VI: The Secret of Saurus Rock

The Land Before Time VI The Secret of Saurus Rock is a 1998 directtovideo animated adventure musical film and the sixth film in The Land Before Time series about five dinosaurs who live in the Great Valley. It is the first film in which Thomas Dekker is both the singing and speaking voice of Littlefoot.

The next day when the kids are playing, Littlefoot accidentally falls off a cliff. Just before he hits the ground, a gruff Whiptail rescues him. This longneck introduces himself only as Doc and gives no knowledge of his history. Littlefoot is intrigued by this newcomer, who is scarred across one eye and displays prior knowledge of the Great Valleys topography.For the preceding reasons, Littlefoot assumes that Doc is the Lone Dinosaur. He tells his friends this, narrating an apparently extemporaneous legend to support his assumption. Inspired, Ceras infant nieces, the twins Dinah and Dana, go to Saurus Rock without anyone noticing. The next day, A worried Cera informs Littlefoot that Dinah and Dana are missing. While searching for them, they Recall their talk of the day before, they go to Saurus Rock to find them. ........

Source: Wikipedia