Scientists work out just how massive megalodon sharks really were

With a fin the size of an adult human, these monsters of the sea were jumbo-size predators.

Amanda Kooser
Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
2 min read

If great white sharks give you the cold sweats, you'll be secretly glad the storied megalodon shark is extinct. Especially since we now have a better idea of just how gigantic it was. Spoiler: It was nightmare-huge.

A study led by researchers at Swansea University and the University of Bristol in the UK, and published Thursday in Scientific Reports, harnessed the power of mathematics to crunch the numbers of Otodus megalodon's size. They figured out that the creature's dorsal fin would've reached over 5 feet (1.6 meters) high, and that the monster would've stretched 52 feet (16 meters) in length. That's longer than a typical city bus.

Scientists don't have a lot to work with when it comes to reconstructing exactly what megalodon looked like. It lived between 23 million to about 3 million years ago, and most of what remains are startlingly large fossil teeth. 

Enlarge Image

This illustration shows an average adult human diver in comparison to a megalodon dorsal fin.

Oliver E. Demuth

Previous efforts to suss out megalodon's size relied on comparing the extinct beast with great white sharks, which can top 20 feet (6 meters) in length. The study's lead author, Jack Cooper, and his team expanded the comparison to include five modern sharks. 

"Megalodon is not a direct ancestor of the great white but is equally related to other macropredatory sharks such as the makos, salmon shark and porbeagle shark, as well as the great white," said co-author Catalina Pimiento of Swansea University. "We pooled detailed measurements of all five to make predictions about megalodon."

The researchers studied how modern sharks grew and applied that growth curve data to megalodons. This new understanding of the ancient predator's size might help scientists figure out the mystery of why it went extinct.

We don't have any living megalodons to look to, but shark fans can always dive into the 2018 action movie The Meg to get a thrill. It makes Jaws look like a kitten.