Release Message:  Cowboy Tuck Kirby (James Franciscus) seeks fame and fortune by capturing a Gwangi (Tyrannosaurus Rex) living in the Forbidden Valley and putting it in a Mexican circus.

Description:  Cowboy James Franciscus seeks fame and fortune by capturing a Tyrannosaurus Rex living in the Forbidden Valley and putting it in a Mexican circus. His victim, called the Gwangi, turns out to have an aversion to being shown in public.