The family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives.
Gavialinae is a subfamily of large semiaquatic crocodilian reptiles, resembling crocodiles, but with much thinner snouts. Gavialinae is one of the two major subfamilies within the family Gavialidae - the other being the subfamily Tomistominae, which contains the false gharial and extinct relatives.
Melanosuchus is a genus of caiman. The black caiman of South America is the sole extant (living) species, and is the largest living member of the subfamily Caimaninae, as well as the entire alligator family Alligatoridae.
Ceratosuchus is an extinct genus of alligatorine crocodylian from latest Paleocene rocks of Colorado's Piceance Basin and earliest Eocene rocks of Wyoming's Bighorn Basin in North America, a slice of time known as the Clarkforkian North American Land Mammal Age. Like its modern relatives, Ceratosuchus was a swamp-dwelling predator. It is named for the pair of flattened, triangular bony plates that extend from the back of its head.
Wannaganosuchus is an extinct genus of small alligatorid crocodylian. It was found in Late Paleocene-age rocks of Billings County, North Dakota, United States.
Albertochampsa is an extinct genus of globidontan alligatoroid from the Late Cretaceous of Alberta. It was named in 1972 by Bruce Erickson, and the type species is A. langstoni. It is known from a skull from the Campanian-age Dinosaur Park Formation, where it was rare; Leidyosuchus is the most commonly found crocodilian at the Park. The skull of Albertochampsa was only about 21 cm long (8.3 in).
Procaimanoidea is an extinct genus of alligatorid from the Eocene of North America. It was named posthumously in 1946 by Charles W. Gilmore; the type species is P. utahensis, from the Uintan of Utah. It is based on USNM 15996, a nearly complete skull and partial left hind leg. A second species, P. kayi, was named in 1941 by C.C. Mook as a species of Hassiacosuchus, for remains from the Bridgerian of Wyoming. It was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht.
A caiman is an alligatorid belonging to the subfamily Caimaninae, one of two primary lineages within the Alligatoridae family, the other being alligators. Caimans inhabit Mexico and Central & South America from marshes and swamps to mangrove rivers and lakes. They have scaly skin and live a fairly nocturnal existence. They are relatively small-sized crocodilians with an average maximum weight of 6 to 40 kg depending on species, with the exception of the black caiman, which can grow more than 4 m (13 ft) in length and weigh in excess of 1,000 kg. The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. The smallest species is the Cuvier's dwarf caiman, which grows to 1.2 to 1.5 m long. There are six different species of caiman found throughout the watery jungle habitats of Central and Southern America. The average length for most of the other caiman species is about 2 to 2.5 m long.
Eocaiman is an extinct genus of caiman containing species living from the Early Paleocene to Miocene in what is now Argentina, Itaboraí Formation of Brazil and Colombia. Eocaiman contains three described species: E. cavernensis, E. palaeocenicus, and E. itaboraiensis, and is typically recovered as one of the more basal members of Caimaninae. Notocaiman was synonymized with Eocaiman paleocenicus in 2022.
Allognathosuchus is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921.
Navajosuchus is an extinct genus of alligatorine crocodylian. Its fossils have been found in the Paleocene-age Nacimiento Formation of the San Juan Basin, New Mexico. It was named in 1942 by Charles C. Mook, and the original type species was N. novomexicanus. N. novomexicanus was based on AMNH 5186, a partial skull collected in 1913. Later research showed that Navajosuchus novomexicanus was the same as the earlier-named Allognathosuchus mooki. However, A. mooki does not belong to the genus Allognathosuchus, and so the name of the crocodilian becomes Navajosuchus mooki. Under whichever name is used, this animal would have been a generalized predator of the Nacimiento floodplains. It was the most common Nacimiento Formation crocodilian, found in both the Puercan and Torrejonian faunal assemblages.
Arambourgia is an extinct monotypic genus of alligatorine crocodylian from Europe. It was named in 1905 as Allognathosuchus gaudryi. It was made a separate genus Arambourgia in 1940. This was synonymized with Allognathosuchus haupti in 1990, but later reassigned as its own genus once again in 2004. Arambourgia was likely to have been part of an early dispersal event of alligatorines from North America to Europe during the Eocene epoch. Arambourgia had non-serrated teeth and a deep orienirostral snout, unlike the flatter snouts of most other alligatorids.
Brachychampsa is an extinct genus of alligatoroid, possibly a basal caiman. Specimens have been reported from New Mexico, Colorado, Wyoming, Montana, North and South Dakota, New Jersey, and Saskatchewan, though only those from Montana, Utah, and New Mexico are based on material sufficient to justify the referral. One specimen has been reported from the Darbasa Formation of Kazakhstan, although the species status is indeterminate for the fossil. The genus first appeared during the late Campanian stage of the Late Cretaceous and became extinct during the late Maastrichtian stage of the Cretaceous. Brachychampsa is distinguished by an enlarged fifth maxillary tooth in the upper jaw.
Thoracosaurus is an extinct genus of long-snouted eusuchian which existed during the Late Cretaceous and Early Paleocene in North America and Europe.
Stangerochampsa is an extinct genus of globidontan alligatoroid, possibly an alligatorine or a stem-caiman, from the Late Cretaceous of Alberta. It is based on RTMP.86.61.1, a skull, partial lower jaws, and partial postcranial skeleton discovered in the late Campanian–early Maastrichtian-age Horseshoe Canyon Formation. Stangerochampsa was described in 1996 by Wu and colleagues. The type species is S. mccabei. The generic name honors the Stanger family, the owners of the ranch where the specimen was found, and the species name honors James Ross McCabe, who discovered, collected, and prepared it. Stangerochampsa is described as "small to medium–sized"; the type skull is 20.0 centimetres (7.9 in) long from the tip of the snout to the occipital condyle, and is 13.0 centimetres (5.1 in) wide at its greatest, while the thigh bone is 14.2 centimetres (5.6 in) long. It had heterodont dentition, with large crushing teeth at the rear of the jaws.
Globidonta is a clade of alligatoroids that includes alligators, caimans, and closely related extinct forms. It is defined as a stem-based clade including Alligator mississippiensis and all forms more closely related to it than to Diplocynodon. The group's fossil range extends back into the Late Cretaceous with early alligatoroids such as Albertochampsa and Brachychampsa. Extinct globidontans were particularly common in North America and Eurasia, and their modern range also includes South America.
Culebrasuchus is an extinct, monotypic genus of caiman alligatorid known from the Early to Middle Miocene (Hemingfordian) of the Panama Canal Zone of Panama. It contains a single species, Culebrasuchus mesoamericanus.
Globidentosuchus is an extinct genus of basal caimanine crocodylian known from the late Middle to Late Miocene of the Middle and the Upper Members of the Urumaco Formation at Urumaco, Venezuela. Its skull was very short and robust, with large units of spherical teeth used to break the shells of molluscs as part of its durophagus diet. It is thought to be one of the most basal Caimanines, even sharing some traits with alligatorids.
Allodaposuchidae is an extinct clade of eusuchians that lived in Europe during the Late Cretaceous (Santonian-Maastrichtian).
The Salamanca Formation is a geologic formation in the Golfo San Jorge Basin of central Patagonia that yields well-preserved, well-dated fossils from the early Paleocene. Studies of these fossils are providing new data on plant and animal diversity following the end-Cretaceous extinction event.
