It has come to light that some Cretaceous animals like Spinosaurus, Baryonyx and Neovenator salerii had a very sensitive and complex neuroanatomy in the rostrum (in the oral and nasal region). Some similar to modern day crocodiles. Apparently these animals snouts were very in tune to their aquatic surroundings. The sensory pits and neural canals within the snouts of these watery beasts were able to detect the slightest change in temperature, shift of current or something swimming by.
This made these three water loving dinosaurs perfectly adapted for an aquatic lifestyle. Its no wonder these animals were able to get so large. While dinosaurs like Giganotosaurus were busy attempting to take down sauropods 5 times their size, these animals were living the fishing life, having no competition other there their own species.
Here is the link to the actual article. It's a very scientifically detailed read!