How Primitive War Created Its Very Distinctive T-Rex Sound [Exclusive]

When it comes to the term movie magic, few things in that arena rival bringing dinosaurs back from extinction. Steven Spielberg most famously accomplished this in his landmark blockbuster "Jurassic Park" in 1993. In and amongst that movie's many thrilling bits of spectacle, though, the T-rex stands alone as one of the most magical things that Spielberg has ever put to screen. So, making a T-rex stand apart from that particular version of the prehistoric beast in a different movie is no easy task. Nevertheless, director Luke Sparke managed to do just that with "Primitive War."

The movie, which will make its way to VOD in the U.S. on October 3, takes place during the Vietnam War and sees an unfortunate group of soldiers stumble upon a bunch of deadly dinosaurs in the jungle. The dinosaurs in "Primitive War" were designed to be as scientifically accurate as possible, as they weren't human-made re-creations. Indeed, one of the things that sets Sparke's T-rex apart is the very distinctive sound that it makes, particularly when it snaps its jaws.

In the movie, when the T-rex is biting down, a distinctive popping sound can be heard. It's delightfully silly but when I spoke to Sparke in honor of the film's VOD release, he explained that the sound was, at least in part, based on his experience with dangerous animals in Australia. Here's what he had to say about it:

"I mean, it's all organic sound. So, one thing I didn't want was two pieces of log or someone doing foley. So, that particular stuff, the dinosaurs, is pretty organic. Because I've grown up in Australia, I've grown up a fair bit of my time in crocodile areas. When the crocodiles jump out of the water and when they get their prey, you can really hear that pop of their jaw. So, that was really my idea of living in Australia, the reptilian creatures that want to eat you out here, that was really me bringing that part of it to a dinosaur, which I hadn't really seen too much of."

You'll just have to take the director's word about that, but Sparke did try to bring some realism to the proceedings based on things that we can observe in the modern day. So, even though the T-rex jaw popping almost plays like a gag in the movie, it was an attempt at grounding the creatures in some level of realism. Getting that sound right, however, really took some doing. As Sparke went on to explain:

"It was actually one that took us right to the very end. Every time they showed me a sound, I rejected it and wanted to get it a different way until we started stripping back the layers. So, it is actually, I think, an alligator crossed with some other reptilian, I think it's a Komodo dragon in there. All these different creatures of how they sound when they eat something can just sort of push to 11."

"If someone out there wants to prove me wrong on how a T-rex jaw pops, I'm all ears," Sparke quipped.

Sparke and his team made "Primitive War" on a shockingly small budget, less than a tenth of what it costs to make a "Jurassic" movie. The dinosaurs — and there are lots of them — don't look cheap, either, despite what you'd expect from a film with this kind of budget. Instead, Sparke and his team made up for what they lacked in financial resources with dedication and commitment.

The result appears to have been worth it. Audience reception to the film has been very strong, and I personally called it the greatest non-"Jurassic" dinosaur movie ever made. The good news is that author Ethan Pettus, whose novel served as the basis for the film, has a whole series of books for Sparke to dive into. And while it remains to be seen if "Primitive War" actually gets a sequel, it's very much on the filmmaker's mind.

"Primitive War" will become available on VOD and digital in the U.S. starting October 3, 2025.