Marine atomic tests cause changes in the ocean's ecosystem resulting in dangerous blobs of radiation and the resurrection of a dormant dinosaur which threatens London.
| Writing | Robert Abel | Story |
| Directing | Douglas Hickox | Director |
| Writing | Daniel James | Screenplay |
| Directing | Eugène Lourié | Director |
| Writing | Alan J. Adler | Story |
| Writing | Eugène Lourié | Screenplay |
| Camera | Ken Hodges | Director of Photography |
| Production | Ted Lloyd | Producer |
| Sound | Edwin Astley | Original Music Composer |
| Editing | Lee Doig | Editor |
| Art | Harry White | Art Direction |
| Production | David Diamond | Producer |
| Art | Eugène Lourié | Production Design |
| Crew | Willis H. O'Brien | Special Effects |
| Camera | Desmond Davis | Camera Operator |
| Crew | Pete Peterson | Special Effects |
| Costume & Make-Up | Bernadette Ibbetson | Hairstylist |
| Crew | Louis DeWitt | Special Effects |
| Crew | Jack Rabin | Special Effects |
| Costume & Make-Up | Jimmy Evans | Makeup Artist |
| Crew | Irving Block | Special Effects |
| Sound | Richard Marden | Sound Editor |
| Directing | Kim Mills | First Assistant Director |
| Directing | Jennifer Herrinshaw | Continuity |
| Sound | Sid Wiles | Sound |
| Production | Jacques de Lane Lea | Production Manager |
| Costume & Make-Up | Freda Gibson | Wardrobe Master |
| Sound | Edwin Astley | Conductor |
| Visual Effects | Willis H. O'Brien | Visual Effects |
