Dinoshark

The film opens with a baby pliosaur swimming away from a broken chunk of Arctic glacier that Ice calving due to global warming. Three years later, it is a ferocious Predator adult and kills tourists and locals offshore from Puerto Vallarta, Mexico. The protagonist, Trace, is first to notice the pliosaur and witnesses his friend get eaten, but has trouble convincing people that a creature of such antiquity is still alive and eating people.