Reptilia polls: most fascinating sea monster

[Reptilia]

Choose up your favourite. Of course this is a personal selection, if you'd like to choose another one that's not listed here feel free to comment and motivate your choice.

[ZoPteryx]

Out of these choices, I selected Shonisaurus, but I'd say my favorite is probably going to be an undescribed highly derived mosasaur from Morocco.  It apparently has river dolphin-like skull adaptations and a large tail fluke!

[Bowhead Whale]

BASILOSAURUS!!!