'Mystery Monster' Eats Great White Shark

What wolfs down a 9-foot great white shark like a steak dinner? That's what plagued researchers who had tagged a great white in Australia and found the tag washed up on a nearby beach four months later, Australia's News Network reports. Tag data showed a sudden 1,902-foot plunge and a quick increase in temperature, the latter indicating time spent in an animal's digestive system. "I was absolutely blown away," says filmmaker Dave Riggs in a documentary coming from the Smithsonian Institute, Hunt for the Super Predator (see some of it on YouTube).

SPOILER ALERT: Researchers theorized that the 9-footer was eaten by a "colossal cannibal great white shark." Huh? Well according to tracking data, the predator would be roughly 16 feet long and weigh more than 2 tons, reports Geekosystem. No one knows why the attack occurred, but it may have been a territorial issue or the big shark could have just been hungry, Gizmodo Australia reports. In the end, the film "settled on a hypothesis that makes the most sense to me," writes Casey Chan at Gizmodo Australia. "Big sharks eat little sharks." (More unusual news from the deep: Scientists have found a remarkable "underwater graveyard.")