In Jon Turteltaub's underwater monster movie The Meg, Jason Statham battles a giant prehistoric shark - but how does it compare to the real Megalodon, and could Megalodon still be out there? We take a look at this fascinating deep-sea predator, the accuracy of the movie's portrayal, and how we know for sure that Carcharocles megalodon (a.k.a. "Big Tooth") went extinct.

Also starring Li Bingbing, Rainn Wilson and Ruby Rose, The Meg sees a state-of-the-art, privately-funded deep-sea research facility send explorers out to test a theory that the Mariana Trench - the deepest trench in the ocean - is actually even deeper than previously believed. When they get down there, however, things don't go according to plan. The team has to call in disgraced deep-sea rescue diver Jonas Taylor (Statham), who is the only surviving person who have successfully executed a rescue mission at such depths.

The mission to gather information about what's on the ocean floor ends up bringing one of the denizens of that ocean floor up to the surface of the ocean, where Jonas and the team must work to stop the Megalodon before it can turn humanity into its own personal buffet. The Meg is certainly a terrifying sight - but did the real-life Megalodon really look like that?


To find out how close The Meg's Megalodon is to the real thing, Science News consulted paleobiologist Meghan Balk, who compared the depiction of the movie's shark to what we know about the real thing. For starters, if you think that the shark in the movie is ludicrously huge, you're right. Though the Meg is said to be 70 feet long, in actuality the largest known Megalodon was less than 60 feet long, and on average they were closer to 30 feet long - about twice the size of the average great white shark. Aside from the exaggerated size, however, the Megalodon is actually pretty on-point. Balk notes that it has six gills, the correct number for sharks, and is modelled after its closest surviving relative, the great white. “When I looked at it, I was like, oh, they did a pretty good job," said Balk. "They didn’t just create a random shark."

We'll get into the depth at which the movie's Megalodon lives later, when we discuss the possibility of this prehistoric shark actually living in one of the ocean's deep trenches, but the currently known species of shark don't even get down to a fraction of the depths depicted in the movie (more than 36,000 feet), with few even getting further down than 4,000 feet. So, if you do decide to explore the Mariana Trench, you don't have to worry about contending with sharks (though you do have to worry about your body imploding from the atmospheric pressure).

A big factor in Megalodon's extinction was the temperature of the oceans. This behemoth lived in warm, tropical waters, and died out when the oceans cooled millions of years ago. However, The Meg posits that instead of dying out, the shark sought refuge in a warm layer of water on the ocean floor created by hydrothermal vents (basically underwater volcanoes). These hydrothermal vents do exist in the ocean, and they are known for sustaining clusters of interesting marine life. However, the deepest hydrothermal vents that have been discovered are only around 5,000 feet deep.

Overall, for a movie about Jason Statham fighting a giant dinosaur shark, the science in The Meg is actually surprisingly sound - drawing on real-life oceanic elements like hydrothermal vents and thermoclines to create a scenario wherein the Megalodon could have survived. But of course, we know that it didn't... right?


The Mariana Trench is more than 1,500 miles long (roughly the distance from New York City to Dallas, Texas), and the deepest part of it is called Challenger Deep, which is also the deepest point on Earth. The pressure that far down is so enormously great that very few humans have ever ventured there, but one of the few humans who has is none other than Avatar and Titanic director James Cameron. For a documentary called Deepsea Challenge 3D, Cameron piloted a submarine almost seven miles down to the bottom of Challenger Deep, becoming the third person in history to descend that far. He (along with his predecessors Jacques Piccard and Don Walsh, who descended to record depths in 1960) was able to touch down on the ocean floor, which somewhat blows a hole in The Meg's theory that the "bottom" of the Mariana Trench is actually a thermocline: a layer of extremely cold water separating the rest of the ocean from a hidden world of warm water underneath.

That said, there is some interesting science behind the theory presented in the movie. A thermocline is a layer in the ocean at which the water's temperature drops much more rapidly than the water above or below it. There is a thermocline at the base of the ocean's epipelagic zone, or sunlit zone. Once you get to the bottom of the Mariana Trench, the waters are just slightly above freezing (34-39 degrees Fahrenheit) and the atmospheric pressure is around 15,000 pounds per square inch (psi). To put that in perspective, the atmospheric pressure at sea level is about 15 psi, and a car crusher exerts about 2,000 psi.

That's a pretty hostile environment, which is why humans haven't been able to do much exploring at those depths. There are species that have evolved to live that far down, and marine scientists estimate that there could in fact be thousands of undiscovered species lurking in the ocean's depths. However, Megalodon is definitely not one of them, for the simple reason that there's not enough food down there to sustain a 70 foot shark - or even a regular great white shark, for that matter. There have indeed been giants discovered at the bottom of Challenger Deep, but in this case the word "giant" is relative, as these species are giant amoebas - the largest of them being around 4 inches long. There are also sea cucumbers, jellyfish, and other species at these depths, but nothing that would constitute even a small snack for a monster known for feasting upon whales.

So, we know that Megalodon isn't lurking down in the Mariana Trench, but what about elsewhere in the extremely vast ocean? Well, sorry to disappoint (though it should really come as a relief), but we know that Megalodon isn't hiding anywhere else for the simple reason that there's no trace of it. As you can see from the close-up shots of the Megalodon's mouth in The Meg, shark teeth are arranged in rows, and some sharks can have up to 300 teeth in their mouth at any one time. Sharks are constantly shedding and replacing teeth, at an average rate of about one tooth per week, and depending on the species it's possible for sharks to lose tens of thousands of teeth over their lifetime. However, the youngest Megalodon tooth fossil is around 2.6 million years old, so barring the existence of a Megalodon tooth fairy who has secretly been hoarding every tooth lost since then, it's safe to say that this monster has been extinct for a very long time.

Even if the Megalodon tooth fairy were real, we'd still know about the existence of even a single Megalodon because of the impact it would have on the ocean's ecosystem. If a shark of this size were out there preying on whales, giant squid, and other wildlife, it would cut a noticeable swathe through the population. For Megalodon to exist without us noticing, it would need to be a ghost shark - and that's another movie entirely.