The Valley of Gwangi (1969) Warner Bros - Blu-ray Region Free

The discovery of a midget horse, thought to be fifty million years old, prompts members of a Wild West show to venture into Mexico's Forbidden Valley in search of fame and untold wealth. But they are met by prehistoric monsters, including "Gwangi," a giant dinosaur that decimates their ranks.

Extras: Return to the Valley recounts the making of the film with associate producer/creator of special effects Ray Harryhausen