Pterano is the main antagonist in The Land Before Time VII: The Stone of Cold Fire. He is the brother of Petrie's mother and the uncle of Petrie and his siblings.
Many years before the film, Pterano tried to lead a group of dinosaurs to The Great Valley but ended up leading them to a group of Deinonychus who attacked the group killing them all except Pterano who survived having escaped while the other dinosaurs fought on. He was then exiled from the herd as punishment for abandoning his followers though he insisted that the massacre was not his fault.
After reuniting with his sister in The Great Valley, Pterano and his henchmen Rinkus and Sierra began searching for The Stone of Cold Fire, a comet he thought would grant him magical powers. Pterano's primary motive for gaining the stone's power was in the hopes of creating a verbrant paradise for the great valley's residents as redemption for his past actions. Because Ducky had been eavesdropping on their plans and because they saw her as a useful object in their mission the trio kidnapped her during the night and carried her off to the Mysterious Beyond. Littlefoot and his friends followed them to save Ducky. While Pterano began to gradually realize the mistakes he failed in his mission when it was found out that the stone did not contain any magic powers and ended up putting Petrie and the others in danger.
However, he ended up saving them all at the end. He was once again banished by Grandpa Longneck and the other adults to the Mysterious Beyond for a reduced period of five cold times (Five winter years). Pterano appears to have turely changed his ways having accepted his responsiblity for his actions and hoping to make up for them when he returns to the herd.