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.[2] This is a stem-based definition for alligators, and is more inclusive than the crown group Alligatoridae.[3] 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.[3][4][5]
The below detailed cladogram shows one proposal for the internal relationships within Alligatoridae[6] (although the exact alligatoroid phylogeny is still disputed).
The superfamily Alligatoroidea is thought to have split from the crocodile-gharial lineage in the late Cretaceous, about 87 million years ago.[7][8]Leidyosuchus of Alberta is the earliest known genus. Fossil alligatoroids have been found throughout Eurasia as land bridges across both the North Atlantic and the Bering Strait have connected North America to Eurasia during the Cretaceous, Paleogene, and Neogene periods. Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million[8] to about 65 million years ago[7]) and the latter reached South America by the Paleogene, before the closure of the Isthmus of Panama during the Neogene period. The Chinese alligator split from the American alligator about 33 million years ago[8] 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.[9] The alligator's full mitochondrial genome was sequenced in the 1990s.[10] The full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds.[11]
True alligators
The lineage including alligators proper (Alligatorinae) occurs in the fluvial deposits of the age of the Upper Chalk in Europe, where they did not die out until the Pliocene age. The true alligators are today represented by two species, A. mississippiensis in the southeastern United States, which can grow to 15.6 ft (4.6 m) and weigh 1000 lbs(453 kg),[12] with unverified sizes of up to 19.2 ft(5.9 m). And the small A. sinensis in the Yangtze River, China, which grows to an average of 5 ft (1.5 m). Their name derives from the Spanishel lagarto, which means "the lizard".
In Central and South America, the alligator family is represented by six species of the subfamily Caimaninae, which differ from the alligator by the absence of a bony septum between the nostrils, and having ventral armour composed of overlapping bony scutes, each of which is formed of two parts united by a suture. Besides the three species in Caiman, the smooth-fronted caimans in genus Paleosuchus and the black caiman in Melanosuchus are described. Caimans tend to be more agile and crocodile-like in their movements, and have longer, sharper teeth than alligators.[13]
C. crocodilus, the spectacled caiman, has the widest distribution, from southern Mexico to the northern half of Argentina, and grows to a modest size of about 2.2 m (7.2 ft). The largest is the near-threatenedMelanosuchus niger, the jacaré-açu or large or black caiman of the Amazon River basin. Black caimans grow to 4.4 m (14.5 ft), with the unverified size of up to 5.7 m (19 ft). The black caiman and American alligator are the only members of the alligator family that pose the same danger to humans as the larger species of the crocodile family.
Although caimans have not been studied in depth, scientists have learned their mating cycles (previously thought to be spontaneous or year-round) are linked to the rainfall cycles and the river levels, which increases chances of survival for their offspring.
^Family Alligatoridae (Alligators and Caiman) 2016-03-04 at the Wayback Machine University of Bristol. Quote:"The Alligatoridae appears in the Upper Cretaceous while the genus Alligator first occurs in the Oligocene."
^Brochu, Christopher A. (2003). "Phylogenetic approaches toward crocodylian history" (PDF). Annual Review of Earth and Planetary Sciences. 31 (31): 357–97. Bibcode:2003AREPS..31..357B. doi:10.1146/annurev.earth.31.100901.141308. Archived (PDF) from the original on 2022-10-09.[permanent dead link]
^ abMichael S. Y. Lee; Adam M. Yates (27 June 2018). "Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil". Proceedings of the Royal Society B. 285 (1881). doi:10.1098/rspb.2018.1071. PMC6030529. PMID 30051855.
^Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC8428266. PMID 34567843.
^Hekkala, E.; Gatesy, J.; Narechania, A.; Meredith, R.; Russello, M.; Aardema, M. L.; Jensen, E.; Montanari, S.; Brochu, C.; Norell, M.; Amato, G. (2021-04-27). "Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus". Communications Biology. 4 (1): 505. doi:10.1038/s42003-021-02017-0. ISSN 2399-3642. PMC8079395. PMID 33907305.
^Paula Bona; Martín D. Ezcurra; Francisco Barrios; María V. Fernandez Blanco (2018). "A new Palaeocene crocodylian from southern Argentina sheds light on the early history of caimanines". Proceedings of the Royal Society B: Biological Sciences. 285 (1885): 20180843. doi:10.1098/rspb.2018.0843. PMC6125902. PMID 30135152.
^ abOaks, J.R. (2011). "A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles". Evolution. 65 (11): 3285–3297. doi:10.1111/j.1558-5646.2011.01373.x. PMID 22023592. S2CID 7254442.
^Brochu, Christopher A. (1999). "Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea". Society of Vertebrate Paleontology Memoir. 6: 9–100. doi:10.2307/3889340. JSTOR 3889340.
^Janke, A.; Arnason, U. (1997). "The complete mitochondrial genome of Alligator mississippiensis and the separation between recent archosauria (birds and crocodiles)". Molecular Biology and Evolution. 14 (12): 1266–72. doi:10.1093/oxfordjournals.molbev.a025736. PMID 9402737.
^Green RE, Braun EL, Armstrong J, Earl D, Nguyen N, Hickey G, Vandewege MW, St John JA, Capella-Gutiérrez S, Castoe TA, Kern C, Fujita MK, Opazo JC, Jurka J, Kojima KK, Caballero J, Hubley RM, Smit AF, Platt RN, Lavoie CA, Ramakodi MP, Finger JW, Suh A, Isberg SR, Miles L, Chong AY, Jaratlerdsiri W, Gongora J, Moran C, Iriarte A, McCormack J, Burgess SC, Edwards SV, Lyons E, Williams C, Breen M, Howard JT, Gresham CR, Peterson DG, Schmitz J, Pollock DD, Haussler D, Triplett EW, Zhang G, Irie N, Jarvis ED, Brochu CA, Schmidt CJ, McCarthy FM, Faircloth BC, Hoffmann FG, Glenn TC, Gabaldón T, Paten B, Ray DA (2014). "Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs". Science. 346 (6215): 1254449. doi:10.1126/science.1254449. PMC4386873. PMID 25504731.
^"American alligator". animals.nationalgeographic.com. National Geographic Society.
^Guggisberg, C.A.W. (1972). Crocodiles: Their Natural History, Folklore, and Conservation. p. 195. ISBN978-0-7153-5272-4.
^Adam P. Cossette (2020). "A new species of Bottosaurus (Alligatoroidea: Caimaninae) from the Black Peaks Formation (Palaeocene) of Texas indicates an early radiation of North American caimanines". Zoological Journal of the Linnean Society. 191: 276–301. doi:10.1093/zoolinnean/zlz178.
External links
"Crocodilians: Natural History & Conservation" 2011-07-08 at the Wayback Machinecrocodilian.com
Media related to Alligatoridae at Wikimedia Commons
Data related to Alligatoridae at Wikispecies
August 24, 2023
alligatoridae, family, crocodylians, includes, alligators, caimans, their, extinct, relatives, temporal, range, cretaceous, holocene, preꞒ, namerican, alligator, alligator, mississippiensis, scientific, classificationdomain, eukaryotakingdom, animaliaphylum, c. The family Alligatoridae of crocodylians includes alligators caimans and their extinct relatives AlligatoridaeTemporal range Cretaceous Holocene 1 82 0 Ma PreꞒ Ꞓ O S D C P T J K Pg NAmerican alligator Alligator mississippiensis Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass ReptiliaOrder CrocodiliaClade GlobidontaFamily AlligatoridaeGray 1844SubfamiliesAlligatorinae Caimaninae Contents 1 Phylogeny 2 Evolution 3 True alligators 4 Caimans 5 Taxonomy 6 References 7 External linksPhylogeny Edit A olseni fore limb Alligator prenasalis fossilThe 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 2 This is a stem based definition for alligators and is more inclusive than the crown group Alligatoridae 3 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 3 4 5 Crocodylia Alligatoroidea Leidyosuchus Diplocynodontinae Diplocynodon Globidonta extinct basal Alligatoroid Globidontans Alligatoridae Caimaninae Caiman Melanosuchus Paleosuchus stem based group Alligatorinae Alligator stem based group crown group stem based group stem based group extinct basal Crocodilians possibly including Mekosuchinae Longirostres Crocodyloidea extinct basal crocodiles Crocodylidae crown group stem based group Gavialoidea extinct basal Gavialoids Gavialidae Gavialis Tomistoma crown group stem based group crown group crown group The below detailed cladogram shows one proposal for the internal relationships within Alligatoridae 6 although the exact alligatoroid phylogeny is still disputed Alligatoroidea Leidyosuchus Diplocynodon Alligatoridae Alligatorinae Ceratosuchus Allognathosuchus Navajosuchus Arambourgia Procaimanoidea Wannaganosuchus Alligator prenasalis Alligator mcgrewi Alligator olseni Alligator sinensis Chinese alligatorCulebrasuchus Alligator mississippiensis American alligatorAlligator mefferdi Alligator thomsoni stem based group Caimaninae Stangerochampsa Albertochampsa Brachychampsa Protocaiman Gnatusuchus Globidentosuchus Eocaiman Notocaiman Kuttanacaiman Purussaurus Mourasuchus Necrosuchus Tsoabichi Paleosuchus trigonatus Smooth fronted caimanPaleosuchus palpebrosus Cuvier s dwarf caimanCentenariosuchus Caiman latirostris Broad snouted caimanMelanosuchus niger Black caimanCaiman yacare Yacare caimanCaiman crocodilus Spectacled caimanCaiman brevirostris La Venta Caiman Caiman wannlangstoni stem based group crown group stem based group Evolution EditThe superfamily Alligatoroidea is thought to have split from the crocodile gharial lineage in the late Cretaceous about 87 million years ago 7 8 Leidyosuchus of Alberta is the earliest known genus Fossil alligatoroids have been found throughout Eurasia as land bridges across both the North Atlantic and the Bering Strait have connected North America to Eurasia during the Cretaceous Paleogene and Neogene periods Alligators and caimans split in North America during the early Tertiary or late Cretaceous about 53 million 8 to about 65 million years ago 7 and the latter reached South America by the Paleogene before the closure of the Isthmus of Panama during the Neogene period The Chinese alligator split from the American alligator about 33 million years ago 8 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 9 The alligator s full mitochondrial genome was sequenced in the 1990s 10 The full genome published in 2014 suggests that the alligator evolved much more slowly than mammals and birds 11 True alligators EditThe lineage including alligators proper Alligatorinae occurs in the fluvial deposits of the age of the Upper Chalk in Europe where they did not die out until the Pliocene age The true alligators are today represented by two species A mississippiensis in the southeastern United States which can grow to 15 6 ft 4 6 m and weigh 1000 lbs 453 kg 12 with unverified sizes of up to 19 2 ft 5 9 m And the small A sinensis in the Yangtze River China which grows to an average of 5 ft 1 5 m Their name derives from the Spanish el lagarto which means the lizard Caimans Edit C crocodilus at the Helsinki Tropicario Zoo aquarium in Helsinki Finland in 2010In Central and South America the alligator family is represented by six species of the subfamily Caimaninae which differ from the alligator by the absence of a bony septum between the nostrils and having ventral armour composed of overlapping bony scutes each of which is formed of two parts united by a suture Besides the three species in Caiman the smooth fronted caimans in genus Paleosuchus and the black caiman in Melanosuchus are described Caimans tend to be more agile and crocodile like in their movements and have longer sharper teeth than alligators 13 C crocodilus the spectacled caiman has the widest distribution from southern Mexico to the northern half of Argentina and grows to a modest size of about 2 2 m 7 2 ft The largest is the near threatened Melanosuchus niger the jacare acu or large or black caiman of the Amazon River basin Black caimans grow to 4 4 m 14 5 ft with the unverified size of up to 5 7 m 19 ft The black caiman and American alligator are the only members of the alligator family that pose the same danger to humans as the larger species of the crocodile family Although caimans have not been studied in depth scientists have learned their mating cycles previously thought to be spontaneous or year round are linked to the rainfall cycles and the river levels which increases chances of survival for their offspring Taxonomy EditSee also List of crocodilians extinct An alligator nest at Everglades National Park Florida United States Spectacled caiman head Black caiman Jauaperi River Amazonia Head of smooth fronted caimanFamily Alligatoridae Subfamily Alligatorinae Genus Alligator Alligator hailensis Alligator mcgrewi Alligator mefferdi Alligator mississippiensis American alligator Alligator olseni Alligator prenasalis Alligator sinensis Chinese alligator Alligator thomsoni Genus Allognathosuchus Genus Arambourgia Genus Ceratosuchus Genus Chrysochampsa Genus Eoalligator Genus Hassiacosuchus Genus Krabisuchus Genus Navajosuchus Genus Procaimanoidea Genus Wannaganosuchus Subfamily Caimaninae Genus Acresuchus Genus Bottosaurus 14 Genus Caiman Caiman brevirostris Caiman crocodilus Spectacled caiman Caiman latirostris Broad snouted caiman Caiman lutescans Caiman venezuelensis Caiman wannlangstoni Caiman yacare Yacare caiman Genus Centenariosuchus Genus Chinatichampsus Genus Culebrasuchus Genus Eocaiman Genus Globidentosuchus Genus Gnatusuchus Genus Kuttanacaiman Genus Melanosuchus Melanosuchus fisheri Melanosuchus niger Black caiman Genus Mourasuchus Genus Necrosuchus Genus Orthogenysuchus Genus Paleosuchus Paleosuchus palpebrosus Cuvier s dwarf caiman Paleosuchus trigonatus Smooth fronted caiman Genus Protocaiman Genus Purussaurus Genus TsoabichiReferences Edit Family Alligatoridae Alligators and Caiman Archived 2016 03 04 at the Wayback Machine University of Bristol Quote The Alligatoridae appears in the Upper Cretaceous while the genus Alligator first occurs in the Oligocene Brochu Christopher A 2003 Phylogenetic approaches toward crocodylian history PDF Annual Review of Earth and Planetary Sciences 31 31 357 97 Bibcode 2003AREPS 31 357B doi 10 1146 annurev earth 31 100901 141308 Archived PDF from the original on 2022 10 09 permanent dead link a b Michael S Y Lee Adam M Yates 27 June 2018 Tip dating and homoplasy reconciling the shallow molecular divergences of modern gharials with their long fossil Proceedings of the Royal Society B 285 1881 doi 10 1098 rspb 2018 1071 PMC 6030529 PMID 30051855 Rio Jonathan P Mannion Philip D 6 September 2021 Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long standing gharial problem PeerJ 9 e12094 doi 10 7717 peerj 12094 PMC 8428266 PMID 34567843 Hekkala E Gatesy J Narechania A Meredith R Russello M Aardema M L Jensen E Montanari S Brochu C Norell M Amato G 2021 04 27 Paleogenomics illuminates the evolutionary history of the extinct Holocene horned crocodile of Madagascar Voay robustus Communications Biology 4 1 505 doi 10 1038 s42003 021 02017 0 ISSN 2399 3642 PMC 8079395 PMID 33907305 Paula Bona Martin D Ezcurra Francisco Barrios Maria V Fernandez Blanco 2018 A new Palaeocene crocodylian from southern Argentina sheds light on the early history of caimanines Proceedings of the Royal Society B Biological Sciences 285 1885 20180843 doi 10 1098 rspb 2018 0843 PMC 6125902 PMID 30135152 a b Oaks J R 2011 A time calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles Evolution 65 11 3285 3297 doi 10 1111 j 1558 5646 2011 01373 x PMID 22023592 S2CID 7254442 a b c Pan T Miao J S Zhang H B Yan P Lee P S Jiang X Y Ouyang J H Deng Y P Zhang B W Wu X B 2020 Near complete phylogeny of extant Crocodylia Reptilia using mitogenome based data Zoological Journal of the Linnean Society 191 4 1075 1089 doi 10 1093 zoolinnean zlaa074 Brochu Christopher A 1999 Phylogenetics Taxonomy and Historical Biogeography of Alligatoroidea Society of Vertebrate Paleontology Memoir 6 9 100 doi 10 2307 3889340 JSTOR 3889340 Janke A Arnason U 1997 The complete mitochondrial genome of Alligator mississippiensis and the separation between recent archosauria birds and crocodiles Molecular Biology and Evolution 14 12 1266 72 doi 10 1093 oxfordjournals molbev a025736 PMID 9402737 Green RE Braun EL Armstrong J Earl D Nguyen N Hickey G Vandewege MW St John JA Capella Gutierrez S Castoe TA Kern C Fujita MK Opazo JC Jurka J Kojima KK Caballero J Hubley RM Smit AF Platt RN Lavoie CA Ramakodi MP Finger JW Suh A Isberg SR Miles L Chong AY Jaratlerdsiri W Gongora J Moran C Iriarte A McCormack J Burgess SC Edwards SV Lyons E Williams C Breen M Howard JT Gresham CR Peterson DG Schmitz J Pollock DD Haussler D Triplett EW Zhang G Irie N Jarvis ED Brochu CA Schmidt CJ McCarthy FM Faircloth BC Hoffmann FG Glenn TC Gabaldon T Paten B Ray DA 2014 Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs Science 346 6215 1254449 doi 10 1126 science 1254449 PMC 4386873 PMID 25504731 American alligator animals nationalgeographic com National Geographic Society Guggisberg C A W 1972 Crocodiles Their Natural History Folklore and Conservation p 195 ISBN 978 0 7153 5272 4 Adam P Cossette 2020 A new species of Bottosaurus Alligatoroidea Caimaninae from the Black Peaks Formation Palaeocene of Texas indicates an early radiation of North American caimanines Zoological Journal of the Linnean Society 191 276 301 doi 10 1093 zoolinnean zlz178 External links Edit Crocodilians Natural History amp Conservation Archived 2011 07 08 at the Wayback Machine crocodilian com Family Alligatoridae Gray 1844 alligator fossilworks org Media related to Alligatoridae at Wikimedia Commons Data related to Alligatoridae at Wikispecies Retrieved from https en wikipedia org w index php title Alligatoridae amp oldid 1168398557, wikipedia, wiki, book, books, library,
