On 4 October 2016, the Facebook page Buzz Channel published a video purportedly showing a 50-foot megaladon (a gigantic species of shark that has been extinct for millions of years) at the bottom of the Mariana Trench, the deepest part of Pacific Ocean:
Absolutely Terrifying #Breaking #50ftShark
A 50 foot shark has been found 1 mile down the marina trench. At first, many thought it was a Pacific Sleeper Shark. The issue with that theory is the Pacific Sleeper Shark grow only to 20 feet, the shark featured is 50+ feet long. That measurement is estimated using the length of the cage, which is 10 feet across.
Could this be the last remaining Megalodon? Watch and share!
Buzz Channel's post was rife with misinformation. This video wasn't "breaking," it didn't show a 50-foot shark, it wasn't filmed in the Mariana Trench, and it absolutely didn't capture an extinct megalodon.
The earliest version of this video we could uncover was posted to YouTube in 2008:
That version of the video stated that the footage captured a 7-meter (22-foot) Pacific sleeper shark off the coast of Japan in the Suruga Bay. While certain details of the video are still unclear (such as the date it was made), the clip's description matches that of a shark filmed off the coast of Japan in 1989:
In September 1989, a large female Pacific Sleeper — estimated to be 23 feet (7 metres) long — was filmed from the viewing ports of a submersible at a depth of 4,000 feet (1,220 metres) off Saruga Bay, Japan.
Here's a comparison of the shark in the video and another sleeper shark:
While the shark in the video is indeed large, it would be considered rather small if it were actually a megalodon. Fossil records of that extinct shark species suggest that it reached a size of nearly 60 feet in length.