- Littlefoot (Apatosaurus)
- Cera (Triceratops)
- Petrie (Pterodactyl)
- Ducky (Saurolophus)
- Spike (Stegosaurus)
- Nick Barcelona .... Young Allosaurus (voice)
- Jeff Bennett .... Petrie (voice)
- Nancy Cartwright .... Dana (voice)
- Aria Curzon .... Ducky (voice)
- Thomas Dekker .... Littlefoot (voice)
- Miriam Flynn .... Grandma (voice)
- Sandy Fox .... Dinah (voice)
- John Ingle .... Cera's Dad (voice)
- Kris Kristofferson .... Doc (voice)
- Danny Mann .... Allosaurus (voice)
- Kenneth Mars .... Grandpa (voice)
- Anndi McAfee .... Cera (voice)
Littlefoot's grandfather one night tells them a story about "The Lone Dinosaur", a legendary long neck that once defeated a T. rex all on his own. The T. rex, however, left "The Lone Dinosaur" with a scar slashed right across his left eye. A few days later a huge statue that looks like a big long neck came out of the ground (with the tooth of the T. Rex on it) when there was an earthshake. The dinosaurs called it "Saurus Rock". The legend also says that if anyone damages the statue, bad luck would descend on the valley, then the whole dinosaur world, and then the whole universe!
A few days later when the kids were playing, Littlefoot accidentally fell of a cliff. Just before he hits the ground a strange long neck dinosaur comes and saves Littlefoot. Nobody knows who he is, when people ask his name, he says it's Doc. When Littlefoot speaks to him alone he says he's been to the Great Valley before. Littlefoot sees a scar on his left eye, much like the one "The Lone Dinosaur" supposedly has. When Littlefoot asks him about it, Doc says politely, "kid,I think I hear your little friends callin'." In other words, mind your own business.
Later that day, Littlefoot figures out that Doc must be The Lone Dinosaur. He tells his friends about it and also how Saurus Rock looks just like Doc. Cera's little twin niece and nephew, Dina and Dana; both go to Saurus rock without anyone noticing. Later when the friends were playing they noticed that Dina and Dana were missing! They were trying to figure out where they could be when they realised that with all that talk about Saurus Rock and The Lone Dinosaur that they must have gone to Saurus Rock.
When they finally get to Saurus Rock, they see Dina and Dana on the top of Saurus Rock. As they climb up to rescue them, Dina and Dana fall off the top and land on Cera, which makes the tooth that she was standing on, break off! When they hit the ground the tooth that she was standing on breaks, and breaks their fall.
As they walk home an Allosaurus surprisingly finds them and chases them. As it is chasing them, they come up to a ravine with a log bridge over it. They walk over the bridge, one by one. When they all get over the sharp tooth comes and tries to run over, but the log only beaks and the Allosaurus falls to the bottom of the ravine.
When they get home, Cera is confronted by her father and gets told off for losing the twins. Later that day the all start to have bad luck all the time; even the grown ups have bad luck. Cera’s father and lots of other dinosaurs think that it’s Doc’s fault that all this bad luck is happening. Littlefoot, on the other hand, stands up for him and says that Doc was and is the greatest long neck ever. As Littlefoot gets back to his friends they are all wondering what to do. Littlefoot then goes to fix the problem because he knows that it was their fault that all this bad luck is happening.
He goes to where the Allosaurus fell down the ravine and checks to see if it’s dead. Feeling confident, he goes inside the sharp tooth’s mouth to get a tooth to replace the old broken one. As he starts to push at a tooth he feels a breeze. But wait a minute; if there’s a breeze then the sharp tooth must be breathing, but, if he’s breathing, that means it’s…ALIVE!
Littlefoot jumps out of his mouth and runs away, but the sharp tooth still chases him. Littlefoot fell over and just before the sharp tooth gets him, “The Lone Dinosaur” comes and whips the sharp tooth. Another sharp tooth comes (the one Doc had defeated) and just before they attack Doc, Littlefoot’s Grandpa came to help. Both Doc and Grandpa made the sharp tooths run into a wall and then there was a landslide that fell on top of the sharp teeth. Then with a rumble one the teeth fell out from the pile of rocks.
Littlefoot and his friends then put the tooth back and all the bad luck ends. However, Doc decides to leave. Littlefoot tells him not to go too far, for you never know when they might need a hero. Doc tells him he already has one, and looks at Grandpa. Later that night, Littlefoot and Cera are seen telling some baby dinos (including Dinah and Dana) a story about "The Great Dinosaur" defeating T. rex on his own. However, this legendary longneck bears an uncanny resemblance to Grandpa Longneck.
- The Lone Dinosaur
- Bad Luck
- When You're On Your Own
- Some scenes from this film were shown in Beethoven's 3rd.
- This was the first film in The Land Before Time film series without a narrator.
- This was the last film in the series to use traditional cel animation. All films VII onwards would use the same technique but will be coloured by digital ink and paint rather than transferred onto cels, as the past sequels have done.
- Recently, a minor rumour was spread about Petrie shouting, after the log was pushed down over a ditch, "Let's go cross big bitch!" It was spread through a comment on the Internet Movie Database.
- The second and final film in the series to include blood. They omitted this form of violence for fear it would be too distressing for children.
Film series: The Land Before Time (1988) • The Great Valley Adventure (1994) • The Time of the Great Giving (1995) •
Journey Through the Mists (1996) • The Mysterious Island (1997) • The Secret of Saurus Rock (1998) • The Stone of Cold Fire (2000) • The Big Freeze (2001) • Journey to Big Water (2002) • The Great Longneck Migration (2003) • Invasion of the Tinysauruses (2005) • The Great Day of the Flyers (2006) • The Wisdom of Friends (2007) Journey of the Brave (2016)
Characters: Littlefoot • Cera • Ducky • Petrie • Spike • Chomper • Ruby (The Land Before Time)