Looks like sharks are winning!

But I should have been more clear: By dinosaurs, I don't mean Brontosauruses or even T-rexes...I mean their seagoing predator relatives, like Liopleurodon Ferox [link]
Now imagine them going against prehistoric sharks like the Megalodon : [link]
( keep in mind, in reality, Megladons would not have been in the same time period as Liopleurodons they came millions of years later, after the dinosaur apex superpredators were extinct... )

According to this poll so far, it looks like the battle would look like this: [link]