The giant shark menacing the seas in the new movie The Meg is far more terrifying than a mere Great White; well over 20 times the size of Jaws' killer shark, the megalodon was a predator without parallel, the largest shark ever to exist. But is there any possibility that megalodons still exist, or is The Meg just playing with the irresistible summer blockbuster premise that bigger (in every way) is better?
Once upon a time, megalodons were very real. The name means "big tooth", fitting as its enormous teeth, over a foot in size, were the first evidence that the colossal creature existed. As PLOS reports, they swam all over the Early Miocene oceans approximately 23 million years ago, and stuck around for about 20 million years as apex predators. Fossil evidence shows they ate sperm whales, dolphins, and all variety of rorquals, the largest group of baleen whales including the blue whale, considered the largest animal to ever live. They weren't shy about chomping down on their fellow sharks, either.
The Meg's megalodon is considerably exaggerated, per Hollywood standards, but it wasn't too far from reality. It's hard to extrapolate scale from scant fossil evidence, so while there's still a great deal of debate about the ultimate size of megalodons, anything that can correctly be described as "significantly larger than a Great White" is terrifying enough.
In The Meg, the cinematic megalodon is unleashed when a scientific exploration sub pokes through what was perceived to be the bottom of a deep-sea trench, correctly predicting it was just a thick layer of suspended gas over a completely isolated warmer-water ecosystem. During a rescue mission, the retreating submarines create a temporary heat spot acting like a portal for anything to come or go through the barrier without suffering the effects of deep-sea cold.
While plenty of "living fossils" — a loose term referring to species thought to be completely extinct that are still around and kicking mostly unchanged, according to Gizmodo — have been discovered over the years, the odds of megalodons being one is slim to none. While a number of living fossil species were indeed sharks, most, like the blind shark and Australian ghostshark, are fairly small, under three feet. Even two of the larger species aren't that large; the eerie Goblin shark is around 12 feet, and the sea serpent-looking Frilled shark is about seven feet max. A giant predator the likes of megalodon would leave some evidence of its existence floating around.
For one thing, sharks shed teeth like crazy. They're nearly-perfect eating machines, and need a constant batch of sharp new teeth to keep up with their consumption rate. Even if a megalodon were "trapped" in some part of the ocean, itself unlikely as megalodon comfortably existed in nearly every ocean at a variety of depths, there would still be two types of proof some gigantic eating machine was still swimming the seas. First, some of the megalodon's many teeth would wash up or be found somewhere in the oceans, and with researchers probing all over, none have been found.
Second, some of those teeth would be found still attached to their prey, or at least leave marks on bones that researchers would also find. Historically there's been plenty of fossil whale bones found with markings matching those of megalodon teeth, but whether a megalodon utterly decimated its prey or not, some indirect evidence of its feeding would remain, and given that giant sharks likely at a lot, something would've been discovered by now.
For anyone disappointed that megalodons don't exist today, don't be. Next time you hit the beach, be glad you'll never have to fear that history's largest shark is wading near its waters.