However, a storm overnight cuts the island off from the mainland and the dinosaurs are coming to life. Crooked local overlord Hacker (Fred Engelberg) discovers that a neanderthal was also released from the depths, he seeks to sell the neanderthal to become rich. Once the dinosaurs are active and causing havoc, Bart orders everyone to an old fortress.
Unfortunately the local annoying kid Julio (Alan Roberts) has run off and is having an adventure with the neanderthal and the brontosaurus. Bart has to save Julio and stop the crooked plans of Hacker and avoid becoming a tyrannosaurus' lunch...
Not a terrible stop-motion monster film, the addition of the neanderthal gives the film some comedy when he is scared of a toilet flushing! Although not very original this is straight forward and enjoyable monster action.