Quote:
Originally Posted by
RJman 
Maybe not enormous octopi, but there have been findings of giant squid, no?
And didn't they recently discover another giant aquatic dinosaur of the pliosaur family that was bigger than megalodon?
EDIT for google search.

Predator X - smaller than a megalodon (admittedly ripped from wikipedia):
Quote:
The creature was 15 metres (49 ft) long (less than Carcharocles megalodon), 45,000 kilograms (99,000 lb) in weight and had teeth 30 centimetres (12 in) long.
The jaws of the creature may have been able to exert more force than those of a Tyrannosaurus rex; although, estimates of the strength vary and many believe this not to be true, with one news source stating the bite was over 10 times more powerful than any modern animal and four times more powerful than that of a Tyrannosaurus. It is estimated to have been alive approximately 147 million years ago.