A group of hikers seek shelter in a cave during a sudden storm in the mountains. An anthropologist (Conrad Nagel) already in the cave explains the drawings on the cave walls and the story of the rock people and the shell people in prehistoric times. Directed by Hal Roach and his son, Hal Roach Jr. It's an interesting piece of fantasy adventure but rather slow moving which make its hour and 21 minute running time on the sluggish side. The film's Oscar nominated special effects were quite impressive for its day although the use of enlarged lizards and crocodiles to play dinosaurs may be bothersome for some. I was fine with it. The volcano eruption is very well done. The minimal dialog consists of grunts and a made up "cave man" language. The focus of the film is on the romance between the neanderthal "rock" man (Victor Mature) and the enlightened "shell" woman (Carole Landis). Oddly enough, this film made them stars and 20th Century Fox signed them both to contracts where their careers would blossom. Remade in 1966 with Raquel Welch. With Lon Chaney Jr. as Mature's father.