This Hammer remake of the original 1940 movie opts for using stop-motion animated dinosaurs (by Ray Harryhausen) rather than gluing fins on real lizards, though there is an "homage" to the previous movie when the main caveman, Tumak, encounters a giant iguana out in the rocky desert.
Tumak is kicked out of the Rock Tribe after he gets in a fight with his father, Akoba, who is chief of the tribe. He makes his way through the barren prehistoric wasteland, where he sees a brontosaurus, a giant spider, and a tribe of fur-covered subhumans who live in a cave with a giant pine tree growing out of it. Eventually he stumbles out onto an oceanside beach where he encounters the blonde women of the Shell tribe. They are chasing away a giant sea turtle. Loana (Raquel Welch) immediately takes a liking to Tumak and nurses him back to health. When this more culturally advanced tribe is attacked by an allosaurus that comes into camp he manages to kill it with a spear. Later, Tumak tries to take this spear, which belongs to one of the Shell Men. There's a fight and Tumak is kicked out because of stealing, something they don't do. Loana chooses to go with him. They make their way back to the Rock Tribe, crossing back over that desert, where they witness a battle between a Ceratosaurus and a Triceratops. Once there, it's a bit of a culture shock for Loana since these people are a bit more crude. And there's Nupondi (Martine Beswick), who is interested in Tumak and gets in a fight with Loana. Loana wins. Later, when she's teaching them how to swim, she's snatched by a giant Pterodactyl--and narrowly escapes. Of course, everything comes to an end when the nearby volcano explodes, devastating both tribes. With only half of them left, the suggestion is that a new tribe--a combination of both--has begun.
This is the full- version shown on Fox, which has the additional monsters in the desert and the two scenes with the subhumans. ONE MILLION YEARS B.C is one of my favorite Hammer movies.