The Wild True Story Behind Samuel L. Jackson's Famous Jurassic Park Line

Sam Jackson is one of the most notorious scene stealers in Hollywood. You simply do not cast Samuel L. in a supporting role unless you intend him to upstage your leads literally every time they share a frame in front of the camera. This is one maxim of the entertainment industry that's as true today as it was, say, back in 1993, when Mr. Jackson delivered one of the most memorable lines in the smash hit blockbuster Jurassic Park.

The iconic dinosaur thriller, based on a best-selling book of the same name by Michael Crichton, has grossed over $1 billion since its original debut, making it by far the highest-grossing film of 1993 and a respectable 28th on the all-time list of box office champions (via Box Office Mojo). The franchise-launching film starred Sam Neill (Event Horizon) and Laura Dern (Big Little Lies) as lead scientists Grant and Ellie with fellow A-listers Jeff Goldblum (Independence Day), Richard Attenborough (Rosebud) and BD Wong (Law and Order: SVU) appearing in supporting roles. Jackson appears several slots further down on the casting list, in the bit part of Ray Arnold, the largely desk-bound computer scientist working under the nefarious corporate spy, Dennis Nedry (Wayne Knight).

Despite his limited screen time, Jackson's character delivered one of Jurassic Park's most quotable lines when he exclaimed, "Hold onto your butts!" Viewers who have also read the book will note that this particular turn of phrase does not appear in the source material. "Hold onto your butts!" was the sole creation of screenwriter David Koepp, who recently opened up to Cinema Blend about the infinitely quotable declaration's origin story.

Koepp recently sat down with the Reel Blend podcast to share some behind-the-scenes anecdotes from the production of the iconic dino-disaster flick. According to the screenwriter himself, that famous Jackson line came straight from Back to the Future creator-writer-director Robert Zemeckis.

Koepp fessed up on air, telling Reel Blend, "I was finishing Death Becomes Her when I was writing Jurassic Park, and we had an ending that was really disastrous at first from one of these horrible test screenings where they almost kill you. So we'd very quickly gone out to shoot a new ending for the movie, but there was little time before the movie came out, so we were in the dailies of the reshoots, and there was gonna be no opportunity to redo the reshoots. So this was it, this really had to work. And we sat down in the dailies, and as the lights were going down, Bob Zemeckis said, 'Hold onto your butts.' I happened to be working on the script at that time, and I was like, 'Oh, I love that.' I went back and I typed it into the script immediately, and then Sam Jackson said it. I don't think I ever told Zemeckis that, but that's his line."

There are definitely some creative benefits to spending your time with other writers. Zemeckis was never credited for his contribution, but at least the truth has finally come out.