Tyrannosaurus rex and Megalodon didn’t live at the same time, and even more, one lived on land and the other in the ocean. But nonetheless, they both ruled their ecosystems at the very top of the food chain. But who was the fiercest of them all?

To answer this question, it’s best to break down each mega-hunter. Which one was the biggest, fastest, strongest, and which one survived and thrived the longest before it went extinct?

The Worlds of T. rex and Megalodon

First, let’s look at the worlds in which both species lived and thrived. T. rex lived during the Cretaceous Period between 66 million years and 68 million years ago in the western U.S., in places like present-day Wyoming and Montana.

At the time, its world wasn’t nearly as dry and arid as it is today. The environment was subtropical, like the Gulf Shore of Louisiana. T. rex undoubtedly ruled its environs, noshing on everything it could get its claws on, from smaller dinosaurs to crocodiles and even some mammals. This beast ate flesh but could also bite through bone.

Megalodon, on the other hand, lived much later. It was the largest fish (not whale) to ever swim the seas, and it lived from around 23 million years to 3.6 million years ago, during the Miocene and Pliocene epochs. Similar to T. rex, it ate just about everything that it could catch, from large marine mammals to fish. And it thrived in nearly all the world’s oceans minus those in the polar regions. 

Read More: Almost 2 Billion T. Rexes Once Stomped the Earth

Comparing the Size of Megalodon and T. rex

When these two beasts go head to head, things aren’t exactly even, says Scott Persons, an assistant professor of paleontology at the College of Charleston in Charleston, South Carolina. For starters, there was a huge difference between the two species in terms of size.

There’s a lot of controversy about Megalodon size because nearly all of our information regarding size comes from its teeth since its body is nearly impossible to come by.

“Megalodon is made of cartilage and doesn’t have very high preservation potential, so its odds of getting into the fossil record are very low,” says Persons.

But its teeth can tell us a lot about its potential size. And because it sheds so many, we have lots of them. Researchers are somewhat confident in saying that it reached about 65 feet in length, around the length of a tractor-trailer.

That’s much larger than that of T. rex, which was around 40 feet. Although T. rex was smaller, it’s also important to consider that whales and sharks can be much larger because the buoyancy of water holds them up and defies gravity.

The next important point is to note its hunting prowess, looking at which mega-hunter had the strongest bite force.

“The bite force of Megalodon is somewhere in the neighborhood of 30,000 pounds of force,” says Persons. “T. rex maxes out far lower with 12,000-8,000 pounds of force.” Still, in either case, you wouldn’t want to be on the receiving end of that bite. 

Read More: What Is a Megalodon? Facts About One of the Biggest Sharks in History

How Fast Were These Mega Predators?

Speed is more difficult to get at, and, in fact, there’s been a long history of debate around how fast these creatures really were. Megalodon has to contend with the physical resistance of water, which obviously puts it at a severe disadvantage compared to a predator that runs on land. Taking this into account, most estimations put this giant shark’s swimming speed at around 11 mph.

The debate around T. rex has been intense because it’s difficult to know for sure. Most paleontologists will say that it wasn’t capable of running because of its sheer size and the fact that it moved about on just two feet. But Persons is of the camp that believes T. rex was indeed a runner.

“It just seems improbable that a big predator would be incapable of sprinting,” says Persons. “I’m comfortable saying it could run around 25 mph.”

In the end, both of these dominant species ruled their worlds. They were both fierce mega-hunters. T. rex was smaller and faster with a much-reduced bite force. But unlike Megalodon, it was hardly to blame for its extinction — an asteroid takes the cake for that. Megalodon was bigger and slower with a huge bite force, and its extinction could not be blamed on something otherworldly because, in the end, it was likely outcompeted by other marine predators. 

Read More: 6 Ancient Mega-Predators that Once Ruled the World

Article Sources

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Sara Novak is a science journalist based in South Carolina. In addition to writing for Discover, her work appears in Scientific American, Popular Science, New Scientist, Sierra Magazine, Astronomy Magazine, and many more. She graduated with a bachelor’s degree in Journalism from the Grady School of Journalism at the University of Georgia. She’s also a candidate for a master’s degree in science writing from Johns Hopkins University, (expected graduation 2023).