Eocene crocodylomorphs

Borealosuchus (meaning "northern crocodile") is an extinct genus of crocodyliforms that lived from the Late Cretaceous to the Eocene in North America. It was named by Christopher Brochu in 1997 for several species that had been assigned to Leidyosuchus. The species assigned to it are: B. sternbergii, the type species, from the Maastrichtian (Late Cretaceous) of Colorado, Montana, North Dakota, South Dakota, and Wyoming; B. acutidentatus, from the Paleocene of Saskatchewan; B. formidabilis, from the Paleocene of North Dakota; B. griffithi, from the Paleocene of Alberta; and B. wilsoni, from the

Pristichampsus (from , 'saw' and , 'crocodile') is a non-diagnostic and potentially dubious extinct genus of crocodylian from France and possibly also Kazakhstan that is part of the monotypic Pristichampsidae family. As the type species, Pristichampsus rollinatii, was based on insufficient material when described in 1831 and 1853, the taxonomic status of the genus is in doubt, and other species have been referred to other genera, primarily Boverisuchus.

Dyrosaurus is a genus of extinct crocodylomorph that lived during the Early Eocene. The name Dyrosaurus comes from () the Greek for lizard or reptile, and Dyr for Djebel Dyr (mountain) close to where the type species was discovered. It was a large reptile with an estimated body length of .

Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of f

Barinasuchus (meaning "Barinas crocodile", in reference to where the type material was found) is an extinct genus of sebecid mesoeucrocodylian. It lived in Argentina, Peru, and Venezuela between the middle Eocene and the Late Miocene, ~42–11.6 Ma. Described in 2007, based on a severely damaged specimen from which only a snout tip was recovered, Barinasuchus is known from a single species, B. arveloi, named after Alberto Arvelo Torrealba, a local educator and poet.

extinct species of reptile

"Mesosuchia" is an obsolete name for a group of terrestrial, semi-aquatic, or fully aquatic crocodylomorph reptiles.

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.

Ceratosuchus ("horned crocodile") 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.

Sebecus (meaning "Sobek" in Latin) is an extinct genus of sebecid crocodylomorph from Paleogene period of South America. Like other sebecosuchians, it was entirely terrestrial and carnivorous. The genus is currently represented by two species, the type S. icaeorhinus and S. ayrampu. Several other species have been referred to Sebecus, but were later reclassified as their own genera.

Iberosuchus (meaning "Iberian crocodile") is a genus of extinct sebecosuchian mesoeucrocodylian found in Western Europe from the Eocene. Remains from Portugal was described in 1975 by Antunes as a sebecosuchian crocodilian. This genus has one species: I. macrodon (meaning "large toothed). Iberosuchus was a carnivore. Unlike the crocodilians today, they were not aquatic but were instead terrestrial.

Boverisuchus is an extinct genus of planocraniid crocodyliforms known from the early to middle Eocene (Ypresian to Lutetian stages) of Germany and western North America. It was a relatively small crocodyliform with an estimated total length of approximately .

Planocraniidae is an extinct family of eusuchian crocodyliforms known from the Paleogene of Asia, Europe and North America. The family was coined by Li in 1976, and contains three genera, Boverisuchus, Duerosuchus and Planocrania. Planocraniids were highly specialized crocodyliforms that were adapted to living on land. They had extensive body armor, long legs, and blunt claws resembling hooves, and are sometimes informally called "hoofed crocodiles".

Ayllusuchus is an extinct genus of medium-sized sebecid mesoeucrocodylian. Fossils have been found in the Lumbrera Formation of Argentina (Eocene age, Casamayoran). It possessed a relatively long and low snout compared to other sebecids.

Allognathosuchus (meaning "other jaw crocodile") is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921.

Eogavialis is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles Tomistoma schlegelii, the extant false gharial, and consequently material from the genus was originally referred to Tomistoma. Indeed, it was not until 1982 that the name Eogavialis was constructed after it was realised that the specimens were from a more basal form.

Phosphatosaurus is an extinct genus of dyrosaurid crocodylomorph. It existed during the early Eocene, with fossils having been found from North Africa in Tunisia and Mali. Named in 1955, Phosphatosaurus is a monotypic genus; the type species is P. gavialoides. A specimen has been discovered from Niger, but it cannot be classified at the species level.

Eosuchus ("dawn crocodile") is an extinct genus of eusuchian crocodylomorph, traditionally regarded as a gavialoid crocodilian. It might have been among the most basal of all gavialoids, lying crownward of all other known members of the superfamily, including earlier putative members such as Thoracosaurus and Eothoracosaurus. Fossils have been found from France as well as eastern North America in Maryland, Virginia, and New Jersey. The strata from which specimens have been found date back to the late Paleocene and early Eocene epochs.

Bergisuchus is an extinct genus of small sebecosuchian mesoeucrocodylian known primarily from the Eocene Messel Pit in Germany. Few fossils of Bergisuchus have been discovered, only a single incomplete snout, a few partial lower jaws and some teeth. Despite being fragmentary, the jaw bones are enough to indicate that Bergisuchus had a short, deep, narrow snout and serrated teeth, quite unlike the broad flat snouts of modern crocodylians.

Megadontosuchus is an extinct monospecific genus of gavialoid crocodylian, traditionally regarded as a member of Tomistominae, from the middle Eocene of Italy. Fossils have been found from Monte Duello in the province of Verona. The genus is currently monotypic, with the type and only species being Megadontosuchus arduini. The species was originally named in 1880, although it was assigned to the genus Crocodilius (now spelled Crocodylus). The genus was first erected by paleontologist Charles C. Mook in 1955 along with the genus Kentisuchus, which was also first classified as Crocodilius. No ho

Eremosuchus is an extinct genus of sebecosuchian notosuchian from the Early Eocene El Kohol Formation of Algeria. It was first described on the basis of isolated cranial and postcranial material in 1989, although much of the original collection has since been lost. Like other sebecids it had serrated, blade-like teeth, a condition referred to as ziphodonty. Phylogenetic analysis conducted using Eremosuchus material yield inconclusive results, but overall support a close relationship with the terrestrial members of Sebecidae best known from the Cenozoic of South America, although also well esta

Brachyuranochampsa is an extinct genus of crocodilian.

Kambara is an extinct genus of mekosuchine crocodylian that lived during the Eocene epoch in Australia. It is generally thought to have been a semi-aquatic generalist, living a lifestyle similar to many of today's crocodiles. Four species are currently recognised, the sympatric Kambara murgonensis and Kambara implexidens from sediments near Murgon, the poorly preserved Kambara molnari from the Rundle Formation and the youngest of the four, Kambara taraina, also from the Rundle Formation. Kambara were medium-sized crocodilians, with mature specimens generally reaching lengths from .

Sahitisuchus is an extinct genus of sebecid mesoeucrocodylian known from Rio de Janeiro State of southeastern Brazil. It contains a single species, Sahitisuchus fluminensis. It is a terrestrial sebecid, although it may also have adopted a semi-aquatic lifestyle to some degree, most probably coexisting with the semi-aquatic alligatorid Eocaiman itaboraiensis.

Duerosuchus is an extinct genus of crocodilian. Remains have been found from Corrales del Vino in Zamora, Spain, and are middle Eocene in age (about 40 million years ago). Duerosuchus is known from a single skull that is incomplete but otherwise well preserved, as well as a lower jaw, some osteoderms, and possibly some vertebrae. Duerosuchus is a basal crocodilian thought to be closely related to brevirostrine (or short-snouted) crocodilians, such as alligatoroids. However, the genus was not initially included in a phylogenetic study and its position within Crocodilia was uncertain, until a 20

Tethysuchia is an extinct clade of neosuchian mesoeucrocodylian crocodylomorphs from the late Middle Jurassic (Bathonian stage) to the Early Eocene (Ypresian stage) of Asia, Europe, North America and South America. It was named by the French paleontologist Eric Buffetaut in 1982 as a suborder. Tethysuchia was considered to be a synonym of Dyrosauridae or Pholidosauridae for many years. In most phylogenetic analyses the node Dyrosauridae+Pholidosauridae was strongly supported. De Andrade et al. (2011) suggested that Tethysuchia be resurrected for that node. They defined it as a node-based taxon

Kentisuchus is an extinct genus of gavialoid crocodylian, traditionally regarded as a member of the subfamily Tomistominae. Fossils have been found from England and France that date back to the early Eocene. The genus has also been recorded from Ukraine, but it unclear whether specimens from Ukraine are referable to Kentisuchus.

Eocaiman is an extinct genus of caiman containing species living from the Early Paleocene to Miocene in what is now Argentina (Salamanca and Sarmiento Formations), Itaboraí Formation of Brazil and Colombia (Honda Group). 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.

Hassiacosuchus is an extinct genus of small alligatorid from the early Eocene of Germany, found at the Messel pit. It was named in 1935 by K. Weitzel, and the type species is H. haupti. A second species, H. kayi, was named in 1941 by C.C. Mook for material from the Bridgerian (early Eocene) of Wyoming, but was reassigned to Procaimanoidea in 1967 by Wassersug and Hecht, who also argued that Hassiacosuchus is synonymous with Allognathosuchus. Phylogenetic analyses exclude H. haupti from Allognathosuchus. thumb|Specimen at the Natural History Museum of Basel

Orthogenysuchus is an extinct genus of caimanine alligatorids. Fossils have been found from the Wasatch Beds of the Willwood Formation of Wyoming, deposited during the early Eocene. The type species is O. olseni. The holotype, known as AMNH 5178, is the only known specimen belonging to the genus and consists of a skull lacking the lower jaws. The braincase is filled in by the matrix and most of the suture lines between bones are indiscernible, making comparisons with other eusuchian material difficult.

Dentaneosuchus is a genus of large bodied sebecid crocodylomorph from the Middle Eocene of Issel and Réalmont (France). Originally described as Atacisaurus crassiproratus, the discovery of additional remains led to it being placed in a separate genus in 2023. It was tentatively recovered as the basalmost member of the family Sebecidae. Because of this Dentaneosuchus could play an important part in deciphering the origins and dispersal of European sebecids, as their presence on the continent, far away from their primary range in South America, is still not entirely resolved. It reached a simila