A series of major earthquakes shatter the world. A new ice age seems to be beginning. The world is approaching its final crisis... Only one young geologist seems to appreciate what is happening. The recent shuddering changes in the earth's crust about the Fuji volcanic zone match—-exactly—-the prediction of his long-dead biologist father. That such cataclysmic conditions would unearth, reawaken the dinosaurs in and around Lake Sai...and bring about hell on earth!
— Tony Crawley, House of Hammer, April 1978
A geologist snoops around a remote area where, it is said, dinosaurs once roamed. There have been reports of late that the huge lizards are still alive. Wonder of wonders, they are.
For the Mystery Science Theater 3000 version, please go to the episode recap page.
This story provides examples of:
- Advertised Extra: The titular "monster bird," an absurdly oversized Rhamphorynchus, only appears in the last 20 minutes of the film and is actually irrelevant to the overall plot. It serves purely as an excuse for a couple of action scenes.
- Ankle Drag: The plesiosaur does this to one of its victims, dragging her out of her boat and dangling her upside down.
- Artistic License – Geology: In this movie, a seismologist reveals that they can actually accurately predict earthquakes - something impossible in real life - but don't disclose the predictions publicly to avoid causing panic.
- In the same scene he says "If a dinosaur does appear, we'll also have magnitude 5 earthquakes." Later scenes suggest he means that the conditions required for a hibernating dinosaur to re-awaken would involve earthquakes, but in the context of this scene it sounds like he's saying the presence of dinosaurs will cause earthquakes.
- Artistic License – Paleontology: The Plesiosaurus and Rhamphorynchus are both referred to as dinosaurs, when neither of them actually are. Their monstrous, aggressive behavior is not based in any evidence. Most jarringly, both are several times larger than they were in real life - Plesiosaurus was actually only about 9 feet long, while Rhamphorynchus had a six-foot wingspan. In the movie, the Plesiosaurus can fit a person in its mouth and the Rhamphorynchus is big enough to grab and carry a human adult in a single claw.
- Behemoth Battle: The Plesiosaurus and the Rhamphorhynchus get into one at the film's climax.
- Bolivian Army Ending: The film ends with our protagonists up on Mt. Fuji while it erupts catastrophically, leaving the female lead dangling from a branch over a huge crevice filling with lava. A song with lyrics about accepting death plays on the soundtrack and the "dinosaurs" succumb to the eruption. The male lead reaches out to try and grab the woman's hand. The movie cuts to credits just as he successfully grabs her hand - but he hasn't actually pulled her out from over the crevice, and even if he does, they're already surrounded by fire and lava and geysers of poison gas, with the ground falling apart all around them, making their survival highly unlikely.
- Lampshaded by the heavily-altered Italian version, which features all of the above (except the Japanese ballad), but then goes on to edit in a clearly happy ending for the two protagonists.
- Chekhov's Volcano: The film is entirely set on and around Mt. Fuji, with the action centered around one of the five lakes created by its last eruption centuries earlier. Many of the odd events throughout the film - including small earthquakes, odd animal behavior, and fish in the lake dying off en masse - hint at its impending eruption, which finally occurs during the climax and is ultimately responsible for killing the prehistoric creatures.
- Eye Scream: The Rhamphorhynchus stabs out one of the Plesiosaurus's eyes with its beak.
- Human Popsicle: The eggs of the Plesiosaurus and Rhamphorhynchus were both frozen in an ice cave before they thaw and hatch.
- Kaiju: The final act of the film switches abruptly from being a Jaws ripoff to being a more traditional kaiju film, complete with a poorly-done monster battle in the climax.
- Non-Indicative Name: Neither the Plesiosaurus nor the Rhamphorhynchus are (technically speaking) dinosaurs, let alone birds. Also there is only one Rhamphorhynchus in the movie, and then only in the last 20 minutes.
- Ominous Fog: Lake Sai and the surrounding forest are repeatedly shown shrouded in dense fog for horror sequences.
- Pinball Protagonist: The protagonists are a geologist who only wants to see the prehistoric creature for himself and his sort-of girlfriend, who's in the area for unrelated reasons and just happens to get caught up in things. Neither of them are actually involved in the discovery of either monster or the efforts to stop them, and they don't even see the monsters until the very end. They only ever try to save each other, and by the end it seems almost impossible that they'll survive anyway.
- Prehistoric Monster: The Plesiosaurus and Rhamphorynchus are pretty much mindlessly aggressive.
- Recycled In Space: Jaws in Japan with prehistoric creatures instead of a shark.
- Signs of the End Times: The movie has a somewhat apocalyptic theme, with the return of the prehistoric creatures being just part of a series of strange events that the characters surmise could be nature's inevitable revenge against humankind.
- Soundtrack Dissonance The movie is quite somber and grim, which makes the jazz-funk musical score and multiple pop songs on the soundtrack a rather odd fit. Even the music during scenes of people being bloodily eaten alive sounds like you should be dancing.
- Tail Slap: Both the Plesiosaurus and the Rhamphporynchus keep their pimp tails strong, the former when it first reveals itself by whacking a man out of a boat, and the latter during its reveal attack on the beach by smacking several people during a fly-by.
- Terror-dactyl: The Rhamphorhynchus in the movie is gigantic, much bigger than the real animal. It is also extremely aggressive.
- What Happened to the Mouse?: The Rhamphphorynchus just disappears from the movie; it is shown roaring on the ground as steam goes off in front of it and then never again. It is not shown succumbing to the volcanic eruption as the Plesiosaurus is. For all we know, it could have just lifted off and flew away. The movie doesn't seem concerned with it.
