When Dinosaurs Ruled the Earth (titled When Dinosaurs Ruled the World in the U.K.) is a 1970 British science fiction film from Hammer Films, written and directed by Val Guest, and starring Victoria Vetri. It was produced by Aida Young. This was the third in Hammer's "Cave Girl" series, preceded by One Million Years B.C. (1966) and Prehistoric Women (1967); it was followed by Creatures the World Forgot (1971). Plot The Cliff Tribe led by Kingsor are about to sacrifice three blonde women to their Sun God, but one of the women, Sanna, escapes and is rescued by fishermen of the Seaside Tribe, among whom is Tara, who becomes enamoured with her. Tara takes Sanna to his people, who also worship the Sun God, but without sacrifices. After building a hut for herself, she joins them at a celebration of a successful hunt, in which the men have captured a plesiosaur. The plesiosaur breaks free, but is subsequently killed and butchered. Ayak, a brunette woman who is jealous of Tara's feelings for Sanna, denounces Sanna as a witch and incites the elder women against her. Kingsor and his men arrive, looking for Sanna. She flees, and hunters of her former tribe, led by Kane, give chase. During the search, Kane's search party is attacked by a Chasmosaurus, which gores Kane. When Tara seeks Sanna, the Chasmosaurus charges him and injures Khaku, one of his companions. He is chased to a cliff, where the Chasmosaurus loses its footing and plunges to its death. Khaku dies of his injuries shortly after, while Kane's wounds are tended to by the Seaside tribeswoman Ulido. Khaku's funeral pyre at the shore is followed by a tribal frenzy during which an enraged Ayak burns down Sanna's hut. Sanna meanwhile becomes trapped by a carnivorous plant, and cuts off a portion of her hair in order to escape. As Tara goes looking for Sanna, he finds her hair trapped beneath the plant and assumes she is dead. Satisfied by this, Sanna's former tribe stop hunting her and join with Tara's tribe, with Kane, now healed, marrying Ulido. Sanna seeks shelter in a Megalosaurus eggshell, fooling the mother and its baby into thinking she is one of them. Sanna grows attached to the baby and plays hide-and-seek with it, as well as teaching it to sit. Tara meanwhile sees one of the women in Sanna's tribe dyeing her