crocodilian n : extant archosaurian reptile [syn: crocodilian reptile]

Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period (Campanian stage). They are the closest living relatives of birds (the only known living dinosaurs), as the two groups are the only known survivors of the Archosauria. Members of the crocodilian stem group, the clade Crurotarsi, appeared about 220 million years ago in the Triassic Period and exhibited a wide diversity of forms during the Mesozoic Era.

The correct vernacular term for this group is "crocodilians", not "crocodiles," although the latter term is sometimes used incorrectly to refer to alligators and caiman, or even their distant prehistoric relatives, "marine crocodiles".

Spelling

The group is often spelled 'Crocodylia' for consistency with the genus Crocodylus (Laurenti, 1768). However, Richard Owen used the -i- spelling when he published the name in 1842, so it is generally preferred in the scientific literature . The -i- spelling is also a more accurate Latinization of the Greek κροκόδειλος (krokodeilos, literally "pebble-worm", referring to the shape and texture of the animal).

Description

• • Order Crocodilia
    • Superfamily Gavialoidea
      • Family Gavialidae - Gharials & False Gharials
    • Superfamily Alligatoroidea
      • Family Alligatoridae
        • Subfamily Diplocynodontinae (extinct)
        • Subfamily Alligatorinae - Alligators
        • Subfamily Caimaninae - Caimans
    • Superfamily Crocodyloidea
      • Family Crocodylidae
        • Subfamily Mekosuchinae (extinct)
        • Subfamily Crocodylinae - Crocodiles

Phylogeny

Cladogram after Brochu (1997).

Eusuchia ├──Hylaeochampsa └──┬──Allodaposuchus └──Crocodilia ├──Gavialoidea │ ├──Eothoracosaurus │ └──┬──Thoracosaurus │ └──┬──Argochampsa │ ├──Eosuchus │ └──Gavialidae └──┬──Borealosuchus └──┬──Pristichampsus └──Brevirostres ├──Alligatoroidea │ ├──Leidyosuchus │ ├─?Deinosuchus │ └──Globidonta │ ├──Stangerochampsa │ ├──Brachychampsa │ └──Alligatoridae └──Crocodyloidea ├──Prodiplocynodon └──┬──Asiatosuchus └──┬──Brachyuranochampsa └──┬──Harpacochampsa └──Crocodylidae

In popular culture

• Several science fiction movies have giant crocodilians as their stars, such as Lake Placid, DinoCroc, and the crocodile series.

References

External links

• Before Crocodiles, the Hairless Coyote
• Florida's Museum of Natural History's Crocodilians Natural History & Conservation site
• International Crocodile Rescue
• Mikko's Phylogeny Archive Crocodyliformes