In The Land Before Time VI: The Secret of Saurus Rock, a pair of Sharpteeth serve as the antagonistic forces of the film. They are a Tyrannosaurus and an Allosaurus respectively.
When Threehorn twins - Dinah and Dana - are playing on their way to Saurus Rock, they do not know they are being followed by the theropod. Before she can catch them she accidentally gets her head stuck in a redwood tree.
Later, she is encountered by Littlefoot, Ducky, Petrie, Cera, and Spike while they are traveling to get the twins back from the monolith. They mistake it for a tree trunk at first, but soon realize that it is the Sharptooth's foot, and run away as she escapes from the tree. She yet again fails when she gets his head stuck between two more trees.
After retrieving Dinah and Dana, during their journey back home she is encountered once again. The Allosaurus quietly sneaks behind Cera, and though her friends try to warn her, she believes they are playing a joke on her. Once the Sharptooth drools on his head, Cera realizes that she's really there, and she and her friends run for safety. The children hide in a rotting log, which the Allosaurus grabs in her jaws and throws towards a ravine that they had crossed earlier, where it becomes lodged between each side like a bridge.
Although Cera briefly gets stuck trying to get out of a hole on the log, the children, save for Spike, manage to get to the other side, while their pursuer attempts to cross the unstable log after them. Spike remains stuck in the log, but while the Sharptooth tries to devour Spike, Littlefoot and Petrie free him. As Spike pops out, the Sharptooth bites into the log causing it to break, sending her falling into the canyon below.
Later, when Littlefoot attempts to retrieve a tooth from the apparently dead Allosaurus (so as to repair the damage done to Saurus Rock), she is shown to have survived, and chases after the young Longneck.
Littlefoot manages to escape the Sharptooth by getting though a hole in a rock wall. While the Sharptooth tries to break though the wall, Littlefoot runs into another Sharptooth, which is a Tyrannosaurus. Upon seeing the predator approaching him, Littlefoot shouts for help. Running under his legs, Littlefoot admits that he is in way over his head and that he doesn't want to be a Lone Dinosaur anymore. The Sharptooth turns and immediately goes after the young Longneck, who soon loses his footing and trips. Just than a shadow appears over him. At first thinking it to be Doc, he is soon proven wrong when it turns out to be his Grandfather. Grandpa tells Littlefoot to run while he and the Tyrannosaurus fight.
Soon Littlefoot's friends arrive and watch with him as Grandpa effortlessly uses his tail to trip the T. rex. As they cheer him on, Ducky soon points out that he's not over yet. The Allosaurus soon arrives and roars in anger (presumably for having to waste so much of it's time and energy, as Littlefoot was able to escape by moving past a large boulder that the predator couldn't get past so easily). With Grandpa distracted, the Tyrannosaurus gets back up and knocks the elder away. Doc appears and fights them alongside Littlefoot's grandfather who stands himself up again. When the Sharpteeth charge at the two Longnecks, they move out of the way causing the Sharpteeth to crash into a rock spire. As the carnivores are down, the Longnecks pull both sides of the spire with their tails, causing it to break and crumble down, crushing the two carnivores to death.
- Some fans of the franchise believe that the green Sharptooth is the ghost of the Meanest Sharptooth; bedevilling any dinosaur unfortunate enough to enter the canyon. This is thought because of their similar appearance and how the Allosaurus, fighting alongside it, did not seem to notice his counterpart in his territory. However, this could also simply be a coincidence; the first film's Sharptooth and Chomper's Father look nearly identical to both of the two Tyrannosaurus depicted in the film.
- Despite being an Allosaurus, the brown Sharptooth is only depicted with two fingers while the actual dinosaur had three. Despite this, she was shown with the accurate amount of fingers just as he is approaching the log that the gang is hiding in (just before he looks into the limb and sees Ducky poke out of it).
- Curiously, no one in the film questions why the two Sharpteeth are present in the Great Valley, a location which is supposed to be free of predators.