Alligatoroidea

Deinosuchus is an extinct genus of eusuchian, either an alligatoroid crocodilian or a stem-group crocodilian, which lived during the Late Cretaceous around . The first remains were discovered in North Carolina (United States) in the 1850s, and the genus was first described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of

Alligatoroidea is one of three superfamilies of crocodylians, the other two being Crocodyloidea and Gavialoidea. Alligatoroidea evolved in the Late Cretaceous period, and consists of the alligators and caimans, as well as extinct members more closely related to the alligators than the two other groups.

Leidyosuchus (meaning "Leidy's crocodile") is an extinct genus of eusuchian, either an alligatoroid crocodilian or a stem-group crocodilian, from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is L. canadensis. It is known from a number of specimens from the middle Campanian age Dinosaur Park Formation. It was a medium-sized alligatoroid, with a maximum skull length greater than 40 centimeters (16 in). left|thumb|Leidyosuchus canadensis skull dorsal view. left|thumb|Leidyosuchus canadensis skull lateral view. A number of species had been

Brachychampsa is an extinct genus of alligatorid, 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. Some specimens have been reported from the Campanian-aged deposits of Central Asia (Chimkent of Kazakhstan and Kirkuduk of Tajikistan), although the species status is indeterminate for these fossils. The genus first appeared during the late Campanian stage of the Late Cretaceous (Judit

Diplocynodon is an extinct genus of eusuchian, either an alligatoroid crocodilian or a stem-group crocodilian, that lived during the Paleocene to Middle Miocene in Europe. Some species may have reached lengths of , while others probably did not exceed . They are almost exclusively found in freshwater environments. The various species are thought to have been opportunistic aquatic predators.

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 (the American Alligator) and all forms more closely related to it than to Diplocynodon. The group's fossil range extends back into the Campanian stage of 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.

Albertochampsa is an extinct genus of alligatorid (possibly a stem-caiman or a basal alligatorine) 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).

Stangerochampsa is an extinct genus of alligatorid, 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. Stangerocha

Protoalligator is an extinct genus of alligatoroid from the Paleocene Wanghudun Formation of China. It was first described as a species of Eoalligator in 1982 before being placed in its own genus in 2016. The name, which translates to "first alligator", was meant to carry on the same meaning as that of Eoalligator ("dawn alligator") as the latter was thought to be synonymous with another crocodilian by the team describing it. Recent studies have suggested that Protoalligator was part of an early radiation of alligatoroids endemic to Asia known as orientalosuchins, though not all studies agree