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Procaimanoidea Kayi
''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] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). 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'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." 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 isoto ... [...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 extant, with the remaining being 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 missis ... [...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 I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Alligator
The Chinese alligator (; ), also known as the Yangtze alligator (), China alligator, or historically the muddy dragon, is a crocodilian endemic to China. It and the American alligator (''A. mississippiensis'') are the only living species in the genus ''Alligator'' of the family Alligatoridae. Dark gray or black in color with a fully armored body, the Chinese alligator grows to in length and weighs as an adult. It brumates in burrows in winter and is nocturnal in summer. Mating occurs in early summer, with females most commonly producing 20–30 eggs, which are smaller than those of any other crocodilian. The species is an opportunistic feeder, primarily eating fish and invertebrates. A vocal species, adults bellow during the mating season and young vocalize to communicate with their parents and other juveniles. Captive specimens have reached age 70, and wild specimens can live past 50. Living in bodies of fresh water, the Chinese alligator's range is restricted to six regions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Olseni
''Alligator olseni'' (common name Olsen's Alligator, named after Russel Olsen) is an extinct species of alligator. They lived in the Early Miocene period, around 20.4–15.97 million years ago and possibly earlier. Their range was principally in what is now known as Florida, United States, and possibly extending into southeastern Texas. It is a small alligator with an estimated body length of . Classification ''Alligator olseni'' is a member of the subfamily Alligatorinae, within the larger family Alligatoridae. It is closely related to the living American alligator and Chinese alligator, as shown in the cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... below: References olseni Miocene reptiles of North America Fossil taxa described in 1942 {{paleo-ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Mcgrewi
''Alligator mcgrewi'' is an extinct species of alligator described by K.P. Schmidt in 1941. They lived in the Early Miocene period, and their range was principally in what is now Nebraska, United States. It is a small alligator with an estimated body length of . ''A. mcgrewi'' has a unique snout, distinguishing it from other alligator species and implying that it evolved from specific environmental adaptations. Classification ''Alligator mcgrewi'' is a member of the subfamily Alligatorinae, within the larger family Alligatoridae. It is related to the living American alligator and Chinese alligator, as shown in the cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... below: References mcgrewi Miocene reptiles of North America Fossil taxa described in 1941 Taxa ... [...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 Formation, 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 Alligatorinae, 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: ''Caimanoideu ... [...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 crocodilian. 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 sho ... [...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 language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tr ... [...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] |
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. wouters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
