that was my second guess SM, Megalodon just sounds cool to think about still possibly existing

deffinately wasnt a Shark that did it their body temps are nowhere near that, a Orca cant "that we think" dive that deep, that we know of, and their body temps are 97-100 F, which would put it in range with the water temperature of the deep offsetting it a bit...

Sperm Whales tho, can dive to almost 10k feet, and could easily swallow a GW, they get to something like 50 feet, so a 9 foot GW would look like a cut plug to it... i just cant find its body temperature, but being a mammal, its probably dead in that range...

the Sperm Whale is the king of the ocean, that we know of, for now

edit: the Sperm Whales temp is around 91 degrees, with water temps at 50 or 60 at certian depths, it would be dead in the range of 78 degrees... good guess SM