Believe it or not there was a screenplay to this.

Sanna is to be sacrificed to the sun god of her tribe. Why? Because she’s blonde. They are sacrificing blondes due to a phenomenon in the sky. The formation of a moon. She escapes by falling off a cliff into the ocean. She is rescued by Tara, a member of a rival tribe. Tara takes Sanna to his tribe where she is welcomed. A captured Elasmosaurus breaks free and the tribe manages to kill it. They now celebrate the hunt with a feast.

Tara becomes interested in Sanna. While she is building a hut for herself Tara brings her food. Ayak is interested in Tara and becomes jealous of Sanna. Tara goes off hunting. Sanna’s tribe comes looking for her to finish their sacrifice. Ayak tells them where she is so Sanna flees. The members of her tribe follow after her. When Tara comes back from the hunt and finds that Sanna has fled he follows too looking for Sanna.

Next we have lots of different dinosaurs that pick off members of Sanna’s tribe while she is on the run. Tara is finding a trail of dead people while he is looking for Sanna. For awhile he thinks she is dead. Eventually they find each other and have sex in a cave.

There are lots of great looking dinosaurs Giant Crabs and Killer plants. You may see an occasional lizard dressed up in fins but mostly it is stop motion animation. There are men and women in skimpy fur outfits. Some nudity and a sex scene. A couple cat fights. A game of hide and seek with Megalosaurus. (Although it looks nothing like a Megalosaurus.) And very little dialogue.

There are many interesting tidbits with this movie and yes you will want it in your collection. Released in 1970 “When Dinosaurs Ruled the Earth” is Hammer’s third foray into the “cave girl” sub-genre. The first being the 1966 Raquel Welch/Harryhausen movie “One Million Years B.C.”. The second being “Slave Girls” (“Prehistoric Women” in the US release) in 1967. Steven Spielberg paid homage to it by using the title as the banner message on his “Jurassic Park” film. The movie was directed by Val Guest (from Quatermass fame). Visual effects were done by Jim Danforth. It stars Victoria Vetri and Robin Sawdon.

The stop motion is really good. Jim Danforth did a great job on it. He was nominated for an academy award in 1971 for Best Visual Effects. Originally the film was to include a tyrannosaurus, but the very conservative head of Hammer Studio ordered Val Guest and Jim Danforth to remove it because he thought the creature's stance feigned the stereotypical stance of gay men. The film was released on DVD as an exclusive from Best Buy with a G-rating but was quickly recalled because it was the original uncut version and contained nudity. (oops!)

OK, there is one small piece of footage in the film that is a fight between what is supposed to be two dinosaurs. It’s actually a monitor lizard and a small alligator that are dressed up to look like dinosaurs. And they are really fighting. This stupid piece of film is stock footage that came for Irwin Allen’s “The Lost World” released in 1960. Why they used that instead of a stop motion piece I don’t know.

A 27-word "caveman language" was devised for the movie, supposedly drawing on Phoenician, Latin, and Sanskrit sources. Some of the key words in this language are: "neecha" is "stop" or "come back"; "zak" is "gone" or "left"; "akita" is "look" or "see"; "neecro" is "bad" or "evil"; "m'kan" is "kill" or "killed"; "mata" is "dead"; "yo kita" is "go".