2. Crocodilia= Crocodile Crocodile has 3 brothers, Gavialoidea, Alligatoroidea and Crocodyloidea. Crocodile’s Grandfather’s Grandfather’s … Grandfather is Protosuchus, which was born in Triassic period. Crocodiles are ambush hunters, waiting for fish or land animals to come close, then rushing out to attack. As cold-blooded predators, they have a very slow metabolism, and thus can survive long periods without food. Despite their appearance of being slow, crocodiles are top predators in their environment. Many large crocodiles swallow stones which may act as ballast to balance their body or assist in crushing food,similar to grit in birds.