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Procaimanoidea
''Procaimanoidea'' ("Before Caiman-forms") 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 (middle Eocene) 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 (early Eocene) of Wyoming. It was reassigned to ''Procaimanoidea'' in 1967 by Wassersug and Hecht. Description ''Procaimanoidea'' was a small alligatorid, and slightly heterodont, the last four teeth on each side of the jaws having blunt tips. Phylogeny Recent studies have consistently resolved ''Procaimanoidea'' as a member of Alligatorinae, although its relative placement is disputed, as shown by the cladograms below. Cladogram from 2018 Bona ''et al.'' study: Cladogram from 2019 Massonne ''et al.'' study: Cladogram fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arambourgia Gaudryi
''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 (now known as '' Hassiacosuchus haupti''), 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. Recent studies have consistently resolved ''Arambourgia'' as a member of Alligatorinae, although its relative placement is disputed, as shown by the cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allognathosuchus Polyodon
''Allognathosuchus'' (meaning "other jaw crocodile") is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921. Description ''Allognathosuchus'' was a medium-sized predator up to 1.5 m in length. This alligatorine is known for its stout jaws and bulbous teeth, found near the rear of the tooth row in upper and lower jaws. These adaptations have historically been interpreted as having been for crushing mollusks. Isolated bulbous teeth are often assigned to this genus, although such teeth are known from other crocodyliform lineages. Taxonomy The type species, ''A. polyodon'', is from the Eocene-age Bridger Formation of Wyoming; it is based on fossils that are difficult to distinguish from other Paleogene alligatorids. ''A. heterodon'' is from the Eocene-age Wasatch Formation of Wyoming, ''A. wartheni'' is from the Eocene-age Wildwood Formation (also known as the "Wildwood alligatorid" and possibly two species), and ''A. woute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allognathosuchus Wartheni
''Allognathosuchus'' (meaning "other jaw crocodile") is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921. Description ''Allognathosuchus'' was a medium-sized predator up to 1.5 m in length. This alligatorine is known for its stout jaws and bulbous teeth, found near the rear of the tooth row in upper and lower jaws. These adaptations have historically been interpreted as having been for crushing mollusks. Isolated bulbous teeth are often assigned to this genus, although such teeth are known from other crocodyliform lineages. Taxonomy The type species, ''A. polyodon'', is from the Eocene-age Bridger Formation of Wyoming; it is based on fossils that are difficult to distinguish from other Paleogene alligatorids. ''A. heterodon'' is from the Eocene-age Wasatch Formation of Wyoming, ''A. wartheni'' is from the Eocene-age Wildwood Formation (also known as the "Wildwood alligatorid" and possibly two species), and ''A. woute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wannaganosuchus Brachymanus
''Wannaganosuchus'' (meaning "Wannagan crocodile", in reference to the Wannagan Creek site where it was discovered) is an extinct genus of small alligatorid crocodylian. It was found in Late Paleocene-age rocks of Billings County, North Dakota, United States. History and description ''Wannaganosuchus'' is based on SMM P76.28.247, a mostly complete skull and postcranial skeleton missing some vertebrae, coracoids, part of the feet, ribs, and other pieces. A few small bony scutes are also assigned to the genus, but not to the type specimen. SMM P76.28.247 was found semi-articulated in the lower part of the Bullion Creek Formation, near the base of a lignitic clay layer deposited in a marsh setting on a floodplain. ''Wannaganosuchus'' was named in 1982 by Bruce R. Erickson. The type species is ''W. brachymanus''; the specific name means "short forefoot". The skull of SMM P76.28.247 was low, without elevated rims over the eyes, and was long. The snout was sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatorinae
Alligatorinae is a subfamily within the family Alligatoridae that contains the alligators and their closest extinct relatives, and is the sister taxon to Caimaninae (the caimans). Many genera in Alligatorinae are described, but only the genus ''Alligator'' is still living, with the remaining genera extinct. Evolution Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to about 65 million years ago). The Chinese alligator split from the American alligator about 33 million years ago and likely descended from a lineage that crossed the Bering land bridge during the Neogene. The modern American alligator is well represented in the fossil record of the Pleistocene. The alligator's full mitochondrial genome was sequenced in the 1990s. The full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds. Phylogeny Alligatorinae is cladistically defined as ''Alligator mississippiensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hassiacosuchus
''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. ''Hassiacosuchus'' may be the same as ''Allognathosuchus''; Christopher Brochu has recommended continuing to use ''Hassiacosuchus''. The cladogram below from the 2020 Cossette & Brochu study shows the placement of ''Hassiacosuchus'' within Alligatoridae: References External links''Hassiacosuchus''in the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ... Alligatorida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Culebrasuchus Mesoamericanus
''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''. Discovery ''Culebrasuchus'' was first described and named by Alexander K. Hastings, Jonathan I. Bloch, Carlos A. Jaramillo, Aldo F. Rincona and Bruce J. Macfadden in 2013 based on a single holotype skull and three neck vertebrae from the Culebra Formation. ''Culebrasuchus'' is thought to be the most basal member of Caimaninae, meaning that it represents the earliest radiation of caimans in the Americas. The ancestor of ''Culebrasuchus'' likely lived farther north, perhaps in what is now southern Mexico, because before the Miocene most of Panama was underwater. The movement of ''Culebrasuchus'' into the Panama Canal Zone was an early part of the Great American Interchange in which animals dispersed between North and South America across the newly formed Is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligatoridae
The family Alligatoridae of crocodylians includes alligators, caimans and their extinct relatives. Phylogeny The superfamily Alligatoroidea includes all crocodilians (fossil and extant) that are more closely related to the American alligator than to either the Nile crocodile or the gharial. This is a stem-based definition for alligators, and is more inclusive than the crown group Alligatoridae. As a crown group, Alligatoridae only includes the last common ancestor of all extant (living) alligators, caimans, and their descendants (living or extinct), whereas Alligatoroidea, as a stem-based group, also includes more basal extinct alligator ancestors that are more closely related to living alligators than to crocodiles or gavialids. When considering only living taxa (neontology), this makes Alligatoroidea and Alligatoridae redundant. The simplified cladogram below shows Alligatoridae's relationships to other extant (living) crocodilians. The below detailed cladogram show ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratosuchus Burdoshi
''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. The type species is ''C. burdoshi'', a name chosen by the Field Museum after Theodore Burdosh discovered a nearly complete skull on an expedition to Western Colorado in 1937. "Fortunately, a knob of bone projecting from an otherwise undistinguished piece of rock had caught the eye of Mr. Burdosh, and the block had been broughtto the Museum. When the rock was chipped away, the insignificant external lump proved to belong to a fairly complete skull of a fossil crocodilian allied to the alligators; and on one posterior corner it bore a triang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Navajosuchus Mooki
''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 (United States). 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. The precise placement of ''Navajosuchus'' within Alligatoroidea is disputed. Some studies have shown it as a basal member of Alliga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Prenasalis
''Alligator prenasalis'' is an extinct species of alligator from the Late Eocene period. It is well known, with many fossils having been collected from the Chadron and Brule Formations in South Dakota. The species was first named in 1904, but was originally classified as a crocodile in the genus ''Crocodilus''. It was reassigned to the genus ''Alligator'' in 1918 on the basis of more complete material. It is the earliest known member of the genus ''Alligator''. Taxonomy Junior synonyms Several species of extinct alligatorines have been considered junior synonyms of ''A. prenasalis''. These include ''Caimanoidea visheri'', named by paleontologist Maurice Mehl in 1916 from fragmentary material, and ''Allognathosuchus riggsi'', named in 1931 from a single piece of a lower jaw. Both were considered synonymous with the species in 1972 by paleontologist D.W. Higgins. Mehl used two alternate spellings of ''Caimanoidea'' in his 1916 paper: ''Caimanoideus'' and ''Caimanoeda''. Because t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
