If you're a dinosaur enthusiast, for sure you have already heard about this secret (that is not so secret!) from Steven Spielberg's 1993 classic film "Jurassic Park." The sound effects used for the velociraptors in the movie were not recordings of enraged animals, but actually, two tortoises having sex.
In an interview with Vulture, Gary Rydstrom, the sound designer of the film, said that "If people knew where the sounds in Jurassic Park came from, it'd be rated R!"
Rydstrom was asked to create a bunch of different dinosaur sounds from square one since not even a single living person in this world knows what these humongous creatures would have sounded like. His game plan was to spend months recording animal sounds then modifying the noise to make it sound more real and natural.
So, how did he record these two tortoises mating? The story of how he got the recording is very simple and casual, nothing too funny or upsetting.