Australian scientists are seeking a "mystery sea monster" that likely swallowed a 9-foot great white shark. Most likely, it was an even bigger great white shark, specifically a 2-ton "colossal cannibal great white shark." From CNN:
A tracking device previously planted on the (9-foot) shark was found washed up on a beach, and after analysis, it showed that it had suddenly undergone a rapid increase in temperature and a swift 1,900-foot (580-meter) dive beneath the waves.(CNN)
Scientists attribute the more than 30-degree spike in temperature to the shark entering another animal's digestive system, and the unexpected plunge could be explained by the larger animal's rapid descent. Researchers found the tracking device about 2½ miles from where the shark was tagged.