Two Lost Worlds (1951)

An independently produced low-budget adventure film whose action sequences consist of footage from other films, Two Lost Worlds (1951) is a head-scratching experience for the viewer.  If you were to believe the poster and the above trailer, you might well be left thinking that this was going to be a full-blown 'lost world' picture, with the characters encountering all manner of prehistoric life after being shipwrecked on a remote island.  In reality, this part of the story is crammed into the last reel of a film which runs barely over sixty minutes and feels decidedly tacked on to what is otherwise a sea-going adventure story involving clipper ships and pirates.  In between these in sandwiched a romance.  The dinosaur sequences, (followed by the inevitable volcanic eruption that ensures all trace of the lost world is eradicated) feel jarring, as if they were an afterthought to try to both pad out the running-time and provide more box-office draw.

As noted, the main action sequences are all stock footage taken from other movies, with the pirate sequences coming mainly from 1940's Captain Caution, some of the 'Australian' sequences (the whole film was shot in California) use footage from Captain Fury, while the dinosaur fight and the volcanic eruption are the same ubiquitous footage from One Million BC (1940) that found its way into countless low-budget movies of the era.  Thanks to its meandering plot, the film never really builds up any pace, nor does it feel especially cohesive as a story, with each episode so brief as to feel perfunctory.  For contemporary audiences, the most recognisable actor is leading man James Arness (or Jim Arness as he's billed), who would appear in the somewhat more substantive science fiction classic The Thing From Another World that same year.  Director Norman Dawn had a career that stretched back to the silent era and had been something of a pioneer in developing the use of travelling mattes and was the first director to have used back projection - which is probably why the over-familiar battling dinosaurs footage is better integrated with actors from the film it is inserted into than usual.