The Beast from 20,000 Fathoms (1953)
A ferocious dinosaur awakened by an Arctic atomic test terrorizes the North Atlantic and, ultimately, New York City
Gorgo (1961)
Greedy sailors capture a giant lizard off the coast of Ireland and sell it to a London circus Then its mother shows up
The Giant Behemoth (1959)
Marine atomic tests cause changes in the oceans ecosystem resulting in dangerous blobs of radiation and the resurrection of a dormant dinosaur that threatens London