Megalodon Wasn’t a Whale Specialist; It Was an Opportunistic Supercarnivore

A new study shows the megatooth shark may have eaten whatever it could get, rewriting what we thought we knew about this prehistoric giant

Every kid I meet asks me about either T. rex or megalodon. 

It’s a job hazard of being a paleontologist who also happens to have young children and writes online. Kids don’t want to hear about Permian invertebrates or fossil pollen. They want monsters. And in the fossil world, it doesn’t get more monstrous than a school-bus-sized shark with hand-sized teeth.

So anytime new research comes out about either of these ancient icons, I drop what I’m doing and read it. Which is exactly what happened when a new study landed on my desk titled “Miocene marine vertebrate trophic ecology reveals megatooth sharks as opportunistic supercarnivores.”

The paper, published in Earth and Planetary Science Letters, looked at the long-standing assumption that Otodus megalodon, the star of every “real sea monster” show, was a top-tier whale killer. Turns out, the reality was messier, and way more interesting.

The researchers, led by Dr. Jeremy McCormack at Goethe University Frankfurt, did something simple in concept but powerful in execution: they looked at fossil teeth from a bunch of Miocene marine animals (sharks, whales, even sea bream) and measured the ratio of zinc isotopes inside.

Why zinc? Because when animals eat other animals, the heavier isotope of zinc (zinc-66) shows up less in their teeth. So by comparing how much zinc-66 is in a fossilized tooth, you can tell where that animal sat in the food chain. Less zinc-66? Higher up the food web.

The team analyzed 209 teeth from 19 marine species (plus two land mammals for comparison), all from about 18 million years ago, in what used to be a shallow sea over present-day southern Germany. Among them were teeth from Otodus megalodon and its close relative O. chubutensis. 

These are sharks so large that they probably needed 100,000 calories a day just to keep swimming (just keep swimming).

But let’s look at the methods, shall we? 

The process was meticulous. Researchers drilled enamel powder from the fossil teeth, purified the zinc using specialized chemistry, and ran the samples through high-precision mass spectrometers. They also dated some of the teeth using strontium isotopes to check if age differences explained dietary variation.

And just to be sure the results weren’t some fluke of fossilization or ancient seawater chemistry, they compared the zinc results from these extinct sharks to those of modern species like great white sharks and dolphins.

And what did they find?

The main takeaway: Megalodon wasn’t a fussy eater. While its average zinc isotope values place it near the top of the food web, right where you’d expect a 20-meter shark to be, there was a lot more variation than scientists had anticipated. 

Some specimens had isotope signatures that matched animals farther down the food chain. That means megalodon populations weren’t all eating the same thing. Some were eating whales. Others? Maybe large fish, smaller sharks, or whatever was around and meaty enough to bite.

One of the most surprising findings was that the great white shark’s ancestor, Carcharodon hastalis, showed higher zinc values than modern great whites. That suggests it ate lower on the food web, perhaps relying more on fish than marine mammals, likely due to the fact it didn’t yet have the iconic serrated teeth that help today’s great whites tear through thick blubber.

And the differences didn’t stop there. When comparing two fossil sites (Sigmaringen and Passau), the researchers found that Otodus teeth from Passau had significantly higher zinc values. Meaning? The sharks from that region may have fed on lower-trophic prey. The authors suggest this could reflect regional differences in prey availability, or even a shift in food sources over time as sea levels changed and prey communities reshuffled.

As Dr. McCormack put it: “Megalodon was by all means flexible enough to feed on marine mammals and large fish, from the top of the food pyramid as well as lower levels — depending on availability.”

That kind of flexibility paints a very different picture from the one we’ve often seen, where megalodon is portrayed as a specialist predator with a taste for baby whales. It might have been more like a huge, cold-blooded raccoon: not picky, just hungry.

But why does this matter? 

It’s easy to think of apex predators as invincible. But being at the top of the food chain comes with its own set of vulnerabilities. You need a constant supply of energy-rich prey. You can’t afford to be outcompeted. You’re a giant in an ecosystem that might not always have room for you.

Which is exactly what might have happened to megalodon.

The fossil record shows that during the Pliocene, the kinds of whales and dolphins that megalodon liked to eat began to decline. Meanwhile, the great white shark, smaller, faster, and more energy-efficient, started spreading into new territories. Earlier research by Dr. McCormack and others has already suggested that this overlap might have contributed to megalodon’s extinction.

This new study reinforces that idea, but with more nuance. Megalodon could adapt. It did adapt. But in the end, even an adaptable supercarnivore couldn’t withstand losing its high-calorie meals while a sleeker rival moved in.

As co-author Dr. Kenshu Shimada put it: “Even supercarnivores are not immune to extinction.”

And what’s my biggest takeaway? 

For those of us who teach, write, or parent with a paleontology lens, stories like this keep the work alive. They remind us that fossils aren’t just stone snapshots. They’re pieces of a dynamic world with real animals who lived complex lives. And sometimes, those complexities made the difference between domination and disappearance.

So the next time a kid asks me what megalodon ate, I’ll say: “Almost anything it wanted. But that didn’t save it.”

And then I’ll show them this new study, because monster stories are better when they’re true.

Published in Fossils et al. Follow to learn more about Paleontology and Evolution.

Do you want to become a writer for this Publication? Read the Submission Guidelines and fill out This Form.

Do you want to read more stories like this? You can now subscribe to my newsletter and join a community of over 11,000 Earth lovers!

I’m thrilled you’re here. Stay curious, and thank you for sharing this journey with me!

Best,

Sílvia P-M, PhD Climate Ages