Valley Of The Gwangi

Creature stop-motion effects were by Harryhausen, the last dinosaur-themed film that he animated. He had inherited the film project from his mentor Willis O'Brien, responsible for the effects in the original King Kong (1933). O'Brien had planned to make The Valley of Gwangi decades earlier but died in 1962 before it could be realized. Producer Charles Scheer called it "probably the least of the movies Ray and I made together."