Evil Lord Tyrannos leads the Dinosaurs back to the surface of the Earth, having been living deep underground in secret all these years. He unleashes his monsters and waves of terrestrial mammals mutated by his evil powers on Earth to destroy mankind. He starts with a wave of red dogs. The only thing that can save humanity is, of course, four teenagers! Two of which have the Gemini power which means they merge using cyber power to become a super flying machine with drills.
You might have guessed by now that this is Japanese. The monsters are played by guys in rubber suits, destroyed cardboard buildings. The rest of the footage is anime and it can be a bit jarring at times switching between the two.
This film is made up of four episodes of a TV series (Dinosaur War Izenborg), each episode following the same formula so we get quite a bit of repetition. It is great fun though doesn't make a lot of sense, Tyrannos sounds terrific, though he it does seem like he needs something for his sore throat.