Crocodilia is an order of mostly large, predatory, semiaquatic reptiles, which includes true crocodiles, the alligators, and caimans; as well as the gharial and false gharial. A member of this order is called a crocodilian, or colloquially a crocodile.
The 9 genera and 26 species of Crocodilia are split into 3 families: Alligatoridae, alligators and caimans; Crocodylidae, true crocodiles; and Gavialidae, the gharial and false gharial.
Conventions
Conservation status codes listed follow the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Range maps are provided wherever possible; if a range map is not available, a description of the crocodilian's range is provided. Ranges are based on the IUCN red list for that species unless otherwise noted. All extinct species or subspecies listed alongside extant species went extinct after 1500 CE, and are indicated by a dagger symbol "". Population figures are rounded to the nearest hundred.
Classification The order Crocodilia consists of 26 extant species belonging to 9 genera. This does not include hybrid species or extinct prehistoric species. Modern molecular studies indicate that the 9 genera can be grouped into 3 families.
Family Alligatoridae (Alligators and caimans) Genus Alligator: two species Genus Caiman: three species Genus Melanosuchus: one species Genus Paleosuchus: two species Family Crocodylidae (True crocodiles) Genus Crocodylus: fourteen species Genus Mecistops: two species Genus Osteolaemus: two species Family Gavialidae (Gharial and false gharial) Genus Gavialis: one species Genus Tomistoma: one species
Crocodilians
Family Alligatoridae
The extant Alligatoridae can be recognised by the broad snout, in which the fourth tooth of the lower jaw cannot be seen when the mouth is closed.
Family Crocodylidae
The extant Crocodylidae have a variety of snout shapes, but can be recognised because the fourth tooth of the lower jaw is visible when the mouth is closed.
Family Gavialidae
Gavialidae can be recognised by the long narrow snout, with an enlarged boss at the tip.
References