Roger Corman's 1958 "Teenage Cave Man" (three words), retitled from its original "Prehistoric World" to capitalize on Herman Cohen's Teenage Werewolf and Frankenstein, was released to theaters on a double bill with Cohen's "How to Make a Monster," introducing the Paul Blaisdell costume that would be utilized for his next production "Night of the Blood Beast" (plus stock footage from "Day the World Ended" and "The She-Creature"). Screenwriter R. Wright Campbell was no stranger to Corman, having scripted his directorial debut "Five Guns West," going on to do the same for "Man of a Thousand Faces," "Machine-Gun Kelly," "The Young Racers," "The Secret Invasion," "Hells Angels on Wheels," "Captain Nemo and the Underwater City" and "The Masque of the Red Death." What at first appears to be a simple 50s retread of the Lon Chaney classic "One Million B.C." becomes actually quite watchable, as the tribe depicted here speaks English and lives in the familiar environs of Griffith Park, right there in front of Bronson Caverns. They could qualify as either Hill People or Rock People, though it's a bit jarring to see the Corman repertory company dressed in caveman togs, regulars like Jonathan Haze, Ed Nelson, Beach Dickerson, and lovely Barboura Morris (seen briefly twice, no dialogue). 25 year old Robert Vaughn made his starring debut as The Boy, hardly a teen but questioning the laws of his elders as his father (Leslie Bradley) tries to keep him from venturing across the river to the great beyond. Frank DeKova is naturally cast as the villain, eager to usurp the power of both father and son as tribal leader, and even murdering a visitor astride a horse rather than make peace as requested. Once The Boy journeys into the forbidden zone he finds dinosaurs (footage from both "One Million B.C" and 1948's "Unknown Island"), marauding dog packs, and a strange creature that walks on two legs, supposedly the one whose touch causes instant death. The small role of the blonde maiden is played by Darah Marshall, not to be confused with Sarah Marshall, British-born daughter of actor Herbert Marshall, enjoying a skinny dip under a waterfall to The Boy's approving flute. Vaughn was embarrassed enough to proclaim this his worst film, but by the 1990s there must have been stronger contenders for that title, like Christopher Lee's "Starship Invasions" or John Carradine's "Buried Alive." The final twist typical of a Roger Corman picture was quite a novelty at the time, but has grown tired from overuse in the decades since.