How long have alligators been on earth?

Crocodiles in roughly the form we know them today have been on earth for about 80 million years, since the late Cretaceous period. Their ancestors, the Pseudosuchia, diverged from the dinosaurs in the early Triassic period about 230 million years ago. read more

The Extraordinary Lives of Crocs. Posted 04.28.98; NOVA; Crocodiles are the ultimate survivors. Having arisen some 200 million years ago, they have outlived the dinosaurs by some 65 million years. Even humans, the most fearsome predators ever to stalk the Earth, have failed to force into extinction any of the 23 species of crocodilians. read more