A powerful megalodon thrashed an ancient whale, scientists find

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In the seas millions of years ago, whales were regularly hunted.

Megalodons, bus-sized sharks, are believed to have been dominant ocean predators some 20 to 3.6 million years ago. The now extinct marine legends almost certainly munched on large prey, and now scientists have unearthed fascinating evidence of such a predatory event. Fossilized clues suggest a small whale was ambushed, bitten, and dramatically thrashed by this colossal shark species.

"To have been on the receiving end of a megalodon attack would have spelled almost certain doom," Stephen Godfrey, the curator of paleontology at the Calvert Marine Museum in Maryland, told Mashable. Godfrey was an author of the new research published in the science journal Palaeontologia Electronica.

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You see, megalodons had giant jaws, big enough to easily swallow multiple humans at once. And these jaws held 276 teeth that were replaced by the thousands throughout their lives. That's why fossilized megalodon teeth are so commonly found. I have one on my bookshelf. With so many teeth to spare, an animal has the ability to be an adventurous predator, biting at will. They can waste teeth on haphazard bites.

"To have been on the receiving end of a megalodon attack would have spelled almost certain doom."

"I see predation by megalodon as being violent and almost without parallel, although killer whales today probably come close," Godfrey explained. "If you don’t 'care' about breaking your teeth during an attack, you as a predator could be reckless, acting without restraint or caution."

Yet the whale whose vertebrae were recently uncovered likely survived a violent, long-ago megalodon attack. At least, for a couple of months or so.

An artist's conception of the megalodon attacking a whale, a possible scenario in which the shark fractured the whale's vertebrae. Credit: Art by Clarence (Shoe) Schumaker / Image courtesy of the Calvert Marine Museum

The megalodon attack

A fossil collector for the Calvert Marine Museum, Mike Ellwood discovered the 15 million-year-old fossils, which included two whale vertebrae and a megalodon tooth. Importantly, this big tooth was found touching one of the whale fossils.

The tooth had a chip, meaning it was damaged, perhaps by impacting bone, said Godfrey.

Meanwhile, one of the vertebrae showed evidence of extreme trauma: Specifically, a fracture created by intense compression. A CT scan (which gives extremely detailed views of body structures) confirmed the broken bone and how it was altered. Something caused the whale's spine to sharply and unnaturally curve, which rammed one of the vertebrae into the other. The force was so strong, it broke the front end off the smashing vertebra. "This would have been an excruciatingly painful injury for the whale," a press release about the research explained.

From the sheer severity of the broken bone, Godfrey suspects a megalodon attack. The encounter could have sharply bent the whale's backbone, perhaps as the shark violently thrust upward (as illustrated in the graphic above). The bite, it should be noted, would have come from a relatively "small" megalodon — judging from the size of its tooth — at some 20 feet long. (They grew up to some 60 feet long).

"Yet, it was able to cause such damage to this whale," Godfrey noted.

The chipped megalodon tooth found next to the fractured whale vertebrae. Credit: Image courtesy of the Calvert Marine Museum

The whale vertebra that was majorly broken before fossilization. Credit: Image courtesy of the Calvert Marine Museum

Godfrey and his coauthor do propose other potential causes of the damaged vertebrae. It's possible the whale experienced a seizure and convulsions after exposure to toxic algal blooms (seizures, though none that could break bone, have been observed in whales). It's also possible that another predator, like the ancestor of today's great white shark, or a sperm whale, could have inflected the damage.

"Nonetheless, given a megalodon tooth was found with the vertebra, it does strongly suggest the trauma may have been caused by the high impact bite of a megalodon shark," Phil Sternes, a Ph.D. student at the University of California, Riverside, told Mashable. Sternes, who had no role in the new research, studies sharks and has published research on the megalodon.

The bite didn't immediately kill the whale. Some bone regrew where the vertebra broke off. The researchers estimate the animal lived for some two months. The attacking megalodon may not have fed on this whale, but prehistoric scavengers almost certainly did.

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Apex predator

If a megalodon ambush indeed fractured the whale's spine, it's more evidence that the megalodon was an unrelenting apex predator in the oceans, noted Sternes. It reigned atop the food chain.

Eventually, however, this dominant species went extinct some 3.6 million years ago. It's possible the megalodon was outcompeted by the great white shark, who needed fewer calories to sustain itself, especially if food became scarce. Whales clearly outlived the megalodon, too.

Yet another whale superpredator looms large today, said Godfrey. Us. We've hunted and decimated many whale populations (though some have recovered). We frequently slam into them with ships. Large whales are particularly threatened and yet to recover from intensive whaling. "Of an estimated quarter of a million blue whales, less than 2,000 are estimated to remain," writes the New Zealand Department of Conservation. "Fin whales are less than five percent and humpback and sei whales 10 to 20 percent of their previous abundance. Of an estimated 60,000 southern right whales, only a few thousand remain."

We can minimize the loss of imperiled whale populations, however, by no longer hunting any whale species, and minimizing ship strikes, Godfrey suggested. "In a way, we have taken the place of megalodon as the new marine macropredator…this time I fear for the survival of whales," he said.

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