American Alligator - Taxonomy and Phylogeny

Taxonomy and Phylogeny

The American alligator was first classified by French zoologist François Marie Daudin as Crocodilus mississipiensis in 1801. Georges Cuvier classified the genus Alligator in 1807. The American alligator shares this genus with the Chinese alligator. They are grouped in the family Alligatoridae with the caimans. The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile or the gharial. Members of this superfamily first arose in the Late Cretaceous. Leidyosuchus of Alberta is the earliest known genus. Fossil alligatoriods have been found throughout Eurasia as land bridges across both the North Atlantic and the Bering Strait have connected North America to Eurasia during the Cretaceous and Tertiary periods. Alligators and caimans spilt in North American during the late Cretaceous and the latter reached South America by the early Tertiary, before the closure of the Isthmus of Panama during the Mio-Pliocene era. The Chinese alligator likely descended from a linage that crossed Beringia during the late Tertiary. The modern American alligator is well represented in the fossil record of the Pleistocene.