One Million AC/DC (1969)

This is one of those movies that has cavemen living in the same era as dinosaurs -- scientifically inaccurate, but it makes for a fun movie. Showing that people were no different back then than they are today, the cavemen and cave-women have sex (lots of it), and sometimes jealous men will fight over a woman. Since this movie was written by Ed Wood, even the animals get into the sex swing-of-things: a Tyrannosaurus Rex (which is very obviously a puppet) pulls the top off a cave-woman, and a gorilla pursues women for mating purposes. Because it is a caveman movie (and cavemen didn't talk much), there isn't any snappy Ed Wood dialogue, and that is sorely missed by his fans; however the title of the movie is a great Ed Wood pun.