Alligatorinae

Alligators and caimans split in North America during the early Tertiary or late Cretaceous (about 53 million to about 65 million years ago).{{cite journal|last10= Wu|first10=X.-B.|last9= Zhang|first9=B.-W.|last8= Deng|first8=Y.-P.|last7= Ouyang|first7=J.-H.|last6= Jiang|first6=X.-Y.|last5= Lee|first5=P.-S.|last4= Yan|first4=P.|last3= Zhang|first3=H.-B.|last2= Miao|first2=J.-S.|last1= Pan|first1=T.|title= Near-complete phylogeny of extant Crocodylia (Reptilia) using mitogenome-based data|journal= Zoological Journal of the Linnean Society |year= 2020|volume=191|issue=4|pages=1075–1089|doi= 10.1093/zoolinnean/zlaa074}}{{cite journal|last1= Oaks|first1= J.R.|title=A time-calibrated species tree of Crocodylia reveals a recent radiation of the true crocodiles |journal= Evolution |volume= 65|issue= 11|year= 2011|pages= 3285–3297|doi= 10.1111/j.1558-5646.2011.01373.x|pmid= 22023592|s2cid= 7254442|doi-access= free}} 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.{{cite journal|doi= 10.2307/3889340|title= Phylogenetics, Taxonomy, and Historical Biogeography of Alligatoroidea|last=Brochu|first=Christopher A.|journal=Society of Vertebrate Paleontology Memoir|volume=6|year=1999|pages=9–100|jstor=3889340}} The alligator's full mitochondrial genome was sequenced in the 1990s.{{cite journal|author1=Janke, A. |author2=Arnason, U. |year=1997|title=The complete mitochondrial genome of Alligator mississippiensis and the separation between recent archosauria (birds and crocodiles)|journal=Molecular Biology and Evolution|volume= 14|issue= 12|pages= 1266–72|pmid= 9402737|doi= 10.1093/oxfordjournals.molbev.a025736|doi-access= free}} The full genome, published in 2014, suggests that the alligator evolved much more slowly than mammals and birds.{{cite journal |vauthors=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 |title=Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs |journal=Science |volume=346 |issue=6215 |page=1254449 |year=2014 |pmid=25504731 |pmc=4386873 |doi=10.1126/science.1254449 }}

Alligatorinae is cladistically defined as Alligator mississippiensis (the American alligator) and all species closer to it than to Caiman crocodylus (the spectacled caiman).{{cite journal |last=Brochu |first=C. A. |year=2003 |title=Phylogenetic approaches toward crocodylian history |journal=Annual Review of Earth and Planetary Sciences |volume=31 |issue=31 |pages=357–97 |doi=10.1146/annurev.earth.31.100901.141308 |bibcode=2003AREPS..31..357B |url=http://www.naherpetology.org/pdf_files/970.pdf |access-date=2021-07-26 |archive-date=2015-04-02 |archive-url=https://web.archive.org/web/20150402192747/http://www.naherpetology.org/pdf_files/970.pdf |url-status=usurped }}{{Cite journal | last1 = Brochu | first1 = C. A. | doi = 10.1111/j.1096-3642.2011.00716.x | title = Phylogenetic relationships of Necrosuchus ionensis Simpson, 1937 and the early history of caimanines | journal = Zoological Journal of the Linnean Society | volume = 163 | pages = S228–S256 | year = 2011 | doi-access = free }} This is a stem-based definition for Alligatorinae, and means that it includes more basal extinct alligator ancestors that are more closely related to living alligators than to caimans.

The below cladogram shows the phylogeny of Alligatorinae.{{Cite journal | last1 = Hastings | first1 = A. K. | last2 = Bloch | first2 = J. I. | last3 = Jaramillo | first3 = C. A. | last4 = Rincon | first4 = A. F. | last5 = MacFadden | first5 = B. J. | title = Systematics and biogeography of crocodylians from the Miocene of Panama | doi = 10.1080/02724634.2012.713814 | journal = Journal of Vertebrate Paleontology | volume = 33 | issue = 2 | pages = 239 | year = 2013 | bibcode = 2013JVPal..33..239H | s2cid = 83972694 | doi-access = free }}

{{clade| style=font-size:85%;line-height:85%

|label1=Alligatoridae

|1={{clade

|1=Caimaninae

|label2=Alligatorinae

|2={{clade

|1=Ceratosuchus burdoshi{{extinct}}

|2=Hassiacosuchus haupti{{extinct}}

|3=Navajosuchus mooki{{extinct}}

|4={{clade

|1=Wannaganosuchus brachymanus{{extinct}}

|2=Arambourgia gaudryi{{extinct}}

|3={{clade

|1=Allognathosuchus polyodon{{extinct}}

|2=Allognathosuchus wartheni{{extinct}}

|3=Procaimanoidea kayi{{extinct}} }}

|label4=Alligator

|4={{clade

|1=Alligator prenasalis{{extinct}}

|2={{clade

|1=Alligator mcgrewi{{extinct}}

|2={{clade

|1=Alligator olseni{{extinct}}

|2={{clade

|1=Alligator sinensis Chinese alligator

|2={{clade

|1=Alligator thomsoni{{extinct}}

|2=Alligator mefferdi{{extinct}}

|3=Alligator mississippiensis American alligator }} }} }} }} }} }} }} }} }}

{{Reflist}}

{{Crocodilia|A.}}

{{Extinct Crocodilia|A.}}

{{Crocs}}

{{Taxonbar|from=Q3408905}}

Category:Alligatoridae

Category:Selandian first appearances

Category:Extant Paleocene first appearances

Category:Taxa named by John Edward Gray

Category:Reptile subfamilies

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