The megalodon has been extinct for millions of years, but the huge prehistoric shark still fascinates people today. Reaching 50 feet long, it's thought to be the largest shark to ever stalk the ocean, but according to a new study, the predator may have been brought down by familiar creature: the great white shark.

As Smithsonian reports, the analysis, published in the journal PeerJ, finds that the megalodon may have vanished from seas much earlier that previously believed. Past research showed that the last megalodons died roughly 2.6 million years ago, a time when other marine life was dying off in large numbers, possibly due to a supernova blasting Earth with radiation at the end of the Pliocene epoch.

A team of paleontologists and geologists revisited the fossils that this conclusion was originally based on for their new study. They found that many of the megalodon remains had been mislabeled, marked with imprecise dates, or dated using old techniques. After reassessing the specimens, they concluded that the species had likely gone extinct at least 1 million years earlier than past research indicates.

If the megalodon vanished 3.6 million years ago rather than 2.6 million years ago, it wasn't the victim of supernova radiation. One known factor that could explain the loss of the 13 million-year-old apex predator at this time is the rise of a new competitor: the great white shark. This predator came on the scene around the same time as the megalodon's decline, and though a full-grown great white shark is less than half the size of a mature megalodon, the species still would have been a stressor. Adult great whites likely competed with juvenile megalodons, and with the megalodon's favorite prey—small whales—becoming scarce at this time, this may have been enough to wipe the megalodons from existence.

Even if great white sharks eventually beat megalodons for dominance in the oceans, the megalodon's status as one of the most fearsome predators of all time shouldn't be contested. The giant sharks had 7-inch teeth and a bite stronger than that of a T. rex.

[h/t Smithsonian]