While returning from a military expedition a helicopter crash lands a commando unit in a dense, remote tropical jungle – a lost world populated by dinosaurs. Now they must find a way out of this isolated valley before becoming prey for prehistoric predators.

This Italian-Turkish co-production helmed by genre veteran Antonio Margheriti (using the pseudonym “Anthony M. Dawson”) was cobbled together from a four-part science-fiction miniseries shown on Italian television. In prehistoric times, the muscular Yor (Reb Brown in a loincloth) saves his cave-babe (Corinne Clery) from a dinosaur just before they get zapped into the future to battle bad guys in the familiar desolate wasteland. Genre stalwart John Steiner (Caligole) and the ubiquitous Luciano Pigozzi co-star with Carol Andre.

When a hunter sent back to the prehistoric era runs off the path he must not leave, he causes a chain reaction that alters history in disastrous ways.