Crocodiles are the largest reptiles in the world and the closest living relatives of birds (.). Both are descended from the Archosaurs. The inguinal crocodile is the most dangerous of all crocodiles. It holds the record for the largest crocodile: It can weigh up to a ton, as much as a small car. While most crocodiles live in rivers and lakes, the groin crocodile is the only one that can handle both fresh water and salt water from the sea. In addition to the inguinal crocodile there are many other species, a total of 25, including the Nile crocodile, the tank crocodile, alligators and caimans.