bobwonderbuns said:
Can we narrow it down a bit?
Absolutely with ob on this one. Via the vast power of Google (including the authoritative
Mediterranean Shark Site), one may conclude that the largest observed cetaceans and sharks in the Med include:
Cuvier's beaked whale
Sperm Whale
Fin Whale
Great White Shark
Basking Shark
Smooth Hammerhead
Bluntnose Sixgill Shark (deep water)
White Shark
Of these the Fin and Sperm whales and Basking shark are the largest.
Megalodon is out, as it was long extinct by the Neolithic, the 8th century BC when Jonah is supposed to have existed. If one wants to include that as a serious possibility, one might as well accept a plesiosaur or the Loch Ness Monster as being responsible.
The Whale shark is also out as they do not exist in the Med.
If one wants to take an endlessly translated story from the New Stone Age at face value then the above are the most likely contenders to be the origin of the story. However, obviously no-one is capable of surviving for days in the stomach of one of these animals. The entire story is probably a corruption of a tale told narrating an encounter with such an animal that has been transmitted for generations via oral translation, been exaggerated and embellished before being set to parchment and ultimately interpreted by some as scripture.
The entire Jonah story is, I'm sure, an allegory, but if forced to place money, it'd be a chance encounter with a basking shark, very large and with a huge mouth.