It was the largest shark ever seen on Planet Earth - the size of some World War II combat submarines - but until now no-one really knew whether a stray Megalodon was still lurking somewhere out there in the ocean.
But finally swimmers can rest easy today - on this score at least, there are still plenty of regular sharks about - because boffins have once and for all pinpointed the date when this terrifying beast went extinct.
Writing in the journal PLOS One, a researcher from University of Zurich says that the terror of the high seas died out some 2.6 million years ago.
To work out this date Chris Clements, research assistant, totted up 10,000 estimates for when the beast died out, before using "Optimal Linear Estimation" techniques to calculate when the Megalodon became an ex-shark.
"Though the technique does not give us the exact date when a species went extinct, it gives the date by which it can be assumed that a species has gone extinct," Clements said.
The Megalodon was basically the bad boy of the ocean. It had a length of more than 50 feet - about the same size as the small X class diesel-electric submarines used for special operations by the Royal Navy in World War II. On one occasion an X-craft crippled an enormous German battleship, the Tirpitz, though this would be a big ask for the comparatively poorly armed Megalodon.
Nonetheless the mega-shark was no lightweight. At 110 tonnes, it was about 30 times as heavy as a Great White and is thought to have had the most powerful bite of any animal in the Earth's history.
It was such a ravenous predator, that its extinction may have allowed whales - today's heftiest seagoing fatties - to grow to the sizes we see nowadays.
“When we calculated the time of Megalodon’s extinction, we noticed that the modern function and gigantic sizes of filter feeder whales became established around that time. Future research will investigate if Megalodon’s extinction played a part in the evolution of these new classes of whales,” said Catalina Pimiento of the University of Florida. ®