Sea Crocodile

Sea crocodiles are a group of crocodilians that are descended from a group of Metriorhynchids that made it into the Late Cretaceous, survived the K-T extinction, diversifying into many different species, and made it into modern times, but it is unknown what species of Metriorhynchid all known Metriorhynchid descendants alive today are descended from. They compete successfully with toothed whales, despite the toothed whales still flourishing. They range from the size of an Australian freshwater crocodile to about the size of sperm whale, depending on a species. They are all carnivorous, with many filling different niches from each other, like small Nothosaurus-like forms that feed on aquatic worms and digging crustaceans, to giant pliosaur-like forms that prey on large cephalopods and small pinnipeds and whales.