New Super Predator?

http://www.environmentalaska.us/great-white-sharks.html

The tag from a 9-foot great white shark washed up on the Australian coast four months after being attached by researchers.
Recorded data from the device shows rapid temperature and depth changes that suggests the shark was attacked and consumed by a much larger predator. Currently, the main theory supported by the researchers is that the shark was preyed upon by another, much larger, great white shark.

Watch The Smithsonian Channel's Video: "Something Ate This Shark...But What?"