Trivia

The movie became a cult film in Soviet Russia where it was the only Japanese monster movie to see a release before the 1990s. Interestingly, it wasn't the prehistoric creatures that caught the attention of audiences, but the depiction of a foreign capitalist country with its modern advancements. In particular, Soviet moviegoers were astonished that Japanese people owned Polaroid cameras.

Despite its title, neither of the creatures in this film are actually classified as dinosaurs. The Plesiosaurus is actually classified as a marine reptile with no relation to dinosaurs, while the Rhamphorhynchus is a pterosaur or flying reptile, closely related to dinosaurs but not actually a dinosaur. The two animals are also vastly oversized to make them more monstrous. A real Rhamphorhynchus would have been about the size of a larger seagull.

Upon its release in the Soviet Union in 1979, it became the 19th highest-grossing foreign film of all time at the Soviet box office, with 48.7 million admissions. This was equivalent to approximately 12.2 million Soviet rubles ($19 million), or $66 million adjusted for inflation.

Spoofed on Mystery Science Theater 3000, MST3K, on May 28 1989. This was Season 0, Episode 21 on local TV in St Paul MN. KTMA Channel 25.

Inspiration for the film came from the shark attack movie Jaws (1975) as well as other animal attack films being released in the US. Also, in Scotland, interest in Nessie at Loch Ness was gaining worldwide attention at the time.