As It Happens

How big was the megalodon? Scientists calculate size of prehistoric shark

It was the biggest shark that ever swam in the Earth's oceans, but until this week, scientists didn't know its actual size. 

The apex predator's dorsal fin alone was as tall as a human being

The megalodon was somewhere between 14 and 16 metres long, according to new research. (Warpaint/Shutterstock)


It was the biggest shark that ever swam in the Earth's oceans, but until this week, scientists didn't know its actual size. 

New research published in the journal Scientific Reports determined just how giant the megalodon actually was — no easy feat for a pre-historic apex predator that didn't leave much behind in the way of fossils. 

"A lot of work goes into figure out its size comes from the teeth, as they're by far the most common fossils we have," paleontologist Jack Cooper, one of the study's authors, told As It Happens guest host Helen Mann. 

"Megalodon teeth have been found on every continent except Antarctica."

Researcher Jack Cooper of the University of Bristol holds a megalodon tooth. (Submitted by Jack Cooper)

To calculate the extinct sea creature's size, the team from the University of Bristol and Swansea University used mathematical projections that factored in the size of megalodon teeth, as well as measurements from its living ancestor, the great white shark.

They discovered the megalodon was likely about 16 metres long, on average. That's about 11 Danny DeVitos, or 7.5 Shaqs, according to the website The Measurement of Things

"The most common comparison you'll see on the internet is that it's about as long as two buses," Cooper said.

The researchers also estimated the megalodon had 4.65-metre long head, a 3.85-metre long tail, and dorsal fin of 1.62 metres, which Cooper notes is "very close in comparison to the height of an adult human being."

Women stand inside the jaws of a megalodon at the Military-Historical Museum of Artillery, Engineer and Signal Corps in St. Petersburg in 2013. (Alexander Demianchuk/Reuters)

Cooper says he was thrilled to be a part of the study. He's been obsessed with megalodons since he first learned about them from the BBC program Sea Monsters when he was six years old.

"Little me thought that was just incredible that such a giant shark could have actually existed, and it just hooked me ever since," he said.

Since his latest research was published, he says he's even heard from Sea Monsters host Nigel Marven.

"He found my work and was very congratulatory. So I actually today got to tell him that it was all back to him," Cooper said. "It felt pretty weird."

The great white shark is a distant relative of the megalodon. (Andrew Brandy Casagrande/Discovery Channel/The Associated Press)

The megalodon lived in wide variety of climates and locations, feeding off marine mammals, including small whales. It's been extinct for more than three million years. 

But continues to live on in popular imagination. It's most recent on-screen iteration comes from the 2018 horror movie The Meg.

Cooper, who has both seen the movie and read the book,has two qualms about The Meg's depictions of his favourite sea creature. 

First, there's the fact that the movie's megalodon survived in the deepest depths of the ocean, the Mariana Trench.

"The only life you get there is microscopic life or tiny micro shrimp organisms," he said. "A shark that fed on whales would have needed a huge amount of calories [and] would not have possibly survived on that."

Then there's the size of the movie creature, which is something Cooper is now well-positioned to fact-check.

"Their megalodon is portrayed as about 20 to 25 metres, which is a fair amount too big," he said. "Not taking away from the fact that it was still a very huge creature, of course."

Written by Sheena Goodyear. Interview produced by Menaka Raman-Wilms. 

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