The Cliff Tribe is led by Kingsor (Patrick Allen). He is about to sacrifice to the sun-god three blondes. Three priests clad in dinosaur hides are to do the deed, but Sanna (Victoria Vetri) escapes by jumping off a cliff. She is rescued by Tara (Robin Hawdon) and men of his tribe on a raft. He takes Sanna to his own tribe on the shore, also sunworshippers. She builds a hut for herself and joins them in a feast to celebrate a successful hunt.

The tribe has captured a Plesiosaur, but it breaks free and attacks the tribe until it is burned to death. A brunette named Ayak (Inogen Hassail) favors Tara, but he is interested in Sanna now, bringing her food and gifts. Ayak denounces Sanna as a witch and the two women fight in the water. Kingsor arrives with his tribe, having discovered that Sanna lives. She runs and they pursue her. Sanna hides in a tree and is threatened by a python, but it kills a man instead. They look for her in a cave, but a Chasmosaurus attacks the men, and then they are attacked by vultures. Tara, looking for Sanna, is chased off a cliff by the Chasmosaurus.

A funeral pyre at the shore gets out of control and Ayak burns down Sanna’s hut in the confusion. Sanna is running through a rainforest and is frightened by a Megalania, looking remarkably like a monitor lizard. She is trapped by a carnivorous plant and cuts off her hair to escape. Tara finds the hair and thinks she is dead. Satisfied now, the two tribes merge and intermarry.

Sanna sleeps in a Megalosaurus eggshell. Another egg hatches and the Megalosaurus baby thinks she is his sister. The parent brings her a deer to eat. She responds by diving into a lake and bringing home a fish in her teeth. (I don’t write them; I only review them.) Returning, she finds the dinosaur in a fight with two men, so she distracts the creature to save them. Tara, meanwhile, sees a woman in Sanna’s tribe putting tar on her blonde daughter’s hair so she will not be sacrificed.

Tara’s tribe has been taken over by Kingsor. Tara is carried off by a Rhamphorhynchus to its nest and he rips its wing and knocks it off the nest. He sees Sanna being followed by a dinosaur and thinks she is being chased, but it is her pet. The couple reunites and have sex in Sanna’s cave. They are seen, however, and he is sacrificed by being set adrift on a raft, but a Plesiosaur attacks the raft and he escapes to join Sanna.

The tribe searches for Sanna again and sees the smoke from her fire. Sanna is rescued by her dinosaur friend but Tara is captured again and is to be burnt, again. The tribe is attacked by giant fiddler crabs. The Moon begins forming, causing a tsunami. Sanna saves Tara from the crabs and Kingsor is swept away by the flood. Also, Ayak dies in quicksand. Tara, Sanna, and their friends survive on a raft and watch a lunar eclipse.

This strange film was a British production from Hammer Studios, directed by Val Guest, who directed 14 films for Hammer, mostly comedies, though he did do Quatermass 2 and The Day the Earth Caught Fire. When Dinosaurs Ruled the Earth was based on a treatment from J.G. Ballard. Exteriors were shot in the Canary Islands. The stop-motion animation was created by Jim Sanforth and James Carreras, and it was relatively good. The special effects were in fact nominated for an Oscar in 1971 but lost to Bedknobs and Broomsticks. It was accidentally reissued by Best Buy with the nude scenes intact but listed as G-rated. This is now a collectors item. When Dinosaurs Ruled the Earth was honored by Jurassic Park with a title banner falling across the triumphant T-Rex at the end. The animation is still considered benchmark, though the rest of the film is rather silly.

A caveman language was invented for the film, theoretically based on Phoenician, Latin, and Sanskrit sources, but it got pretty tiresome after a while. A tyrannosaurus was created but not kept in the movie because a Hammer Films executive thought it was too gay. In 1972, the film was shown in a double bill with The Ten Commandments. The female leads nearly drowned fighting in the surf. Victoria Vetri got the role after running around a back lot in a bikini, panting and flaring her nostrils for Francis Ford Coppola. She was Playmate of the Year in 1968. She appeared on TV a lot, but she was in Rosemary’s Baby, where her character was told, “You look like Victoria Vetri.” She was sentenced to nine years in prison for shooting her husband to death in 2011. She pleaded No Contest, meaning I did it but it was not wrong. One wonders just how bad a husband he was.