Metriorhynchus ("Moderate Snout") was a 3 metered long, prehistoric, marine crocodilian which lived in the Late Jurassic Period in England, France, Germany, Argentina, and Chile around 165-145 MYA, during the Late Jurassic time period.
Metriorhynchus lived during the Middle to Late Jurassic Period from 165-145 million years ago. It shared the oceans with other sea creatures from the shark Hybodus to the giants Liopleurodon and Leedsichthys.
Metriorhynchus measured 3 meters long, which was large for a marine crocodile. As a species of sea creature that was described as a type of marine crocodile, they were entirely fitting for existing in the oceans, having great paddle–like feet, nothing like modern crocodiles. Their tails also had no armor plating of any kind. Metriorhynchus had sacrificed defense for speed.
They often lived in shallow waters and had a fish-like tail, and although it was distantly related to modern day crocodiles, Metriorhynchus became completely aquatic: its feet became flippers and it lost the body armor typical of the crocodilians, so its only hope of escaping predators, such as giant Liopleurodon, was its speed.
Metriorhynchus was a versatile hunter and fed mainly on aquatic animals, eating everything such as from the slow moving Ammonites to the faster fish and and larger prey such as the giant fish Leedsichthys and even pterosaurs. Metriorhynchus could also leap up from the water to snag pterosaurs that flew too low with its scissor-like jaws.
Unlike other crocodiles, Metriorhynchus gives birth to several live infants. The mother probably did not take care of her young for very long. They spent most of their time in shallow waters catching anything their size allowed. But sometimes Metriorhynchus came to deeper waters, though this was very rare, usually when hunting the giant fish Leedsichthys.
It was so adapted to life at sea that it probably only returned to land to mate and to lay its eggs. It was not very graceful when out of the water and would have returned to the sea immediately after laying its eggs. The young would have hatched on their own, making a hazardous journey down the beach to the sea.
It also didn't seem to have problems with Hybodus.