Gryposuchinae: Difference between revisions

| subdivision_ranks = SubgroupsGenera

Gryposuchines havehad long, narrow snouts and protruding eye sockets. One distinguishing feature of the group is the lack of a large exposure of the [[prootic bone]] around the trigeminal foramen, a hole in the side of the [[braincase]] wall.<ref name=V-JBS07>{{cite journal |last=Vélez-Juarbe |first=Jorge |author2=Brochu, C.A. |author3= Santos, H. |year=2007 |title=A gharial from the Oligocene of Puerto Rico: transoceanic dispersal in the history of a non-marine reptile |journal=Proceedings of the Royal Society B |volume=274 |issue=1615 |pages=1245–1254 |doi=10.1098/rspb.2006.0455 |pmid=17341454 |pmc=2176176}}</ref>

Gryposuchinae was named in 2007 as a subfamily of closely related gavialid crocodilians. It was [[cladistics|cladistically]] defined as a [[stem-based taxon]] including ''Gryposuchus jessei'' and all crocodilians more closely related to it than to ''Gavialis gangeticus'' (the [[gharial]]) or ''Tomistoma schlegelii'' (the [[False gharial]]).<ref name=V-JBS07/> The [[tomistominae|tomistomines]] (including the living [[false gharial]]) were long thought to be classified as [[crocodile]]s and not closely related to [[gavialoids]].<ref name=Brochu2000>{{cite journal |last=Brochu |first=C.A. |author2=Gingerich, P.D. |year=2000 |title=New tomistomine crocodylian from the Middle Eocene (Bartonian) of Wadi Hitan, Fayum Province, Egypt |journal=University of Michigan Contributions from the Museum of Paleontology |volume=30 |issue=10 |pages=251–268}}</ref> However, recent molecular studies using [[DNA sequencing]] have consistently indicated that the [[false gharial]] (''Tomistoma'') (and by inference other related extinct forms in [[Tomistominae]]) actually belong to [[Gavialoidea]] (and [[Gavialidae]]).<ref name="Harshman2003">{{cite journal |pmid=12775527 |year=2003 |last1=Harshman |first1=J. |title=True and false gharials: A nuclear gene phylogeny of crocodylia |journal=Systematic Biology |volume=52 |issue=3 |pages=386–402 |last2=Huddleston |first2=C. J. |last3=Bollback |first3=J. P. |last4=Parsons |first4=T. J. |last5=Braun |first5=M. J. |doi=10.1080/10635150309323 |url=http://si-pddr.si.edu/bitstream/handle/10088/6275/2003C_Harshman_et_al.pdf |doi-access=free |access-date=2021-06-29 |archive-date=2022-10-09 |archive-url=https://ghostarchive.org/archive/20221009/http://si-pddr.si.edu/bitstream/handle/10088/6275/2003C_Harshman_et_al.pdf |url-status=dead }}</ref><ref name="Gatesy2003">{{cite journal |last=Gatesy |first=Jorge |author2=Amato, G. |author3=Norell, M. |author4=DeSalle, R. |author5= Hayashi, C. |year=2003 |title=Combined support for wholesale taxic atavism in gavialine crocodylians |journal=Systematic Biology |volume=52 |issue=3 |pages=403–422 |doi= 10.1080/10635150309329|pmid=12775528 |url=http://www.faculty.ucr.edu/~mmaduro/seminarpdf/GatesyetalSystBiol2003.pdf|doi-access=free }}</ref><ref name="Willis2007">{{Cite journal | last1 = Willis | first1 = R. E. | last2 = McAliley | first2 = L. R. | last3 = Neeley | first3 = E. D. | last4 = Densmore Ld | first4 = L. D. | title = Evidence for placing the false gharial (''Tomistoma schlegelii'') into the family Gavialidae: Inferences from nuclear gene sequences | doi = 10.1016/j.ympev.2007.02.005 | journal = Molecular Phylogenetics and Evolution | volume = 43 | issue = 3 | pages = 787–794 | date = June 2007 | pmid = 17433721}}</ref><ref name="Gatesy2008">{{cite journal|last1=Gatesy |first1=J. |last2=Amato |first2=G. |year=2008 |title=The rapid accumulation of consistent molecular support for intergeneric crocodylian relationships |journal=[[Molecular Phylogenetics and Evolution]]|volume=48 |issue=3 |pages=1232–1237 |doi=10.1016/j.ympev.2008.02.009|pmid=18372192}}</ref><ref name=bite>{{cite journal| author=Erickson, G. M.| author2=Gignac, P. M.| author3=Steppan, S. J.| author4=Lappin, A. K.| author5=Vliet, K. A.| author6=Brueggen, J. A.| author7=Inouye, B. D.| author8=Kledzik, D.| author9=Webb, G. J. W. | year=2012 | title=Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation | journal=PLOS ONE | volume=7 |issue=3 |page=e31781 |doi=10.1371/journal.pone.0031781|editor1-last=Claessens|editor1-first=Leon|bibcode = 2012PLoSO...731781E | pmid=22431965 | pmc=3303775| doi-access=free}}</ref><ref name="LeeYates2018">{{cite journal | author=Michael S. Y. Lee |author2=Adam M. Yates |date=27 June 2018 |title=Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil |journal=[[Proceedings of the Royal Society B]] |volume=285 |issue=1881 |doi=10.1098/rspb.2018.1071 |pmid=30051855 |pmc=6030529 |doi-access=free}}</ref><ref name="Hekkala2021">{{Cite journal|last1=Hekkala |first1=E. |last2=Gatesy |first2=J. |last3=Narechania |first3=A. |last4=Meredith |first4=R. |last5=Russello |first5=M. |last6=Aardema |first6=M. L. |last7=Jensen |first7=E. |last8=Montanari |first8=S. |last9=Brochu |first9=C. |last10=Norell |first10=M. |last11=Amato |first11=G. |date=2021-04-27 |title=Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, Voay robustus |journal=Communications Biology |language=en |volume=4 |issue=1 |page=505 |doi=10.1038/s42003-021-02017-0 |pmid=33907305 |pmc=8079395 |issn=2399-3642 |doi-access=free}}</ref>

A [[phylogenetic]] analysis conducted in the 2007 study found Gryposuchinae to include the genera ''Aktiogavialis'', ''Gryposuchus'', ''[[Ikanogavialis]]'', ''[[Piscogavialis]]'', and ''[[Siquisiquesuchus]]''. BelowThe is abelow [[cladogram]] is from the 2007 analysis showing the phylogenetic relationships of gryposuchines among [[Gavialoidea|gavialoids]]:.<ref name=V-JBS07/> ''Hesperogavialis'' was excluded due to a lack of skull material, and ''[[Dadagavialis]]'' due to its 2018 discovery.<ref>{{Cite journal|last1=Salas-Gismondi|first1=Rodolfo|last2=Moreno-Bernal|first2=Jorge W.|last3=Scheyer|first3=Torsten M.|last4=Sánchez-Villagra|first4=Marcelo R.|last5=Jaramillo|first5=Carlos|date=2019-06-18|title=New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians|journal=Journal of Systematic Palaeontology|volume=17|issue=12|pages=1049–1075|doi=10.1080/14772019.2018.1495275|s2cid=91495532|issn=1477-2019}}</ref>

The subfamily ''Gryposuchinae'' are the sole members of the superfamily ''[[Gavialoidea]]'' to occupy South America, the duration of which is entirely limited to the Miocene. However, although most of their history is recorded on the continent, dispersion was achieved via a prior presence in the Caribbean (''Aktiogavialis'', the oldest known gryposuchine, from in the Middle Oligocene of Puerto Rico, and ''Dadagavialis'' in the Early Miocene of Panama, respectively).<ref name="V-JBS07" /><ref>{{Cite journal|last1=Salas-Gismondi|first1=Rodolfo|last2=Moreno-Bernal|first2=Jorge W.|last3=Scheyer|first3=Torsten M.|last4=Sánchez-Villagra|first4=Marcelo R.|last5=Jaramillo|first5=Carlos|date=2019-06-18|title=New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians|journal=Journal of Systematic Palaeontology|volume=17|issue=12|pages=1049–1075|doi=10.1080/14772019.2018.1495275|s2cid=91495532|issn=1477-2019}}</ref> Furthermore, indeterminate gavialoid remains have recovered from the Oligo-Miocene boundary of coastal Brazil.<ref name=":1">{{Cite journal|last1=Moraes-Santos|first1=Heloisa|last2=Villanueva|first2=Jean Bocquentin|last3=Toledo|first3=Peter Mann|date=2011-12-01|title=New remains of a gavialoid crocodilian from the late Oligocene−early Miocene of the Pirabas Formation, Brazil|journal=Zoological Journal of the Linnean Society|language=en|volume=163|issue=suppl_1|pages=S132–S139|doi=10.1111/j.1096-3642.2011.00710.x|issn=0024-4082|doi-access=free}}</ref> The origin of these gryposuchines is unclear, although traditionally, an African origin has been favoured as gavialids would have been more likely to cross the [[Atlantic Ocean]] than the longer expanses of the [[Pacific Ocean]]. Moreover, warm equatorial currents run across the Atlantic from Africa to the Americas, assisting in travel.

''[[Gryposuchus]]'', ''[[Ikanogavialis]]'' and ''[[Siquisiquesuchus]]'' represent the first known members of ''Gryposuchinae'' in Early Miocene of South America, colonizing around Colombia and Venezuela. Additionally, indeterminate finds of gavialoids (all in either coastal or marine sediments) are present in early Miocene [[Jimol Formation]] and for the early/middle Miocene [[Castilletes Formation]] in Colombia,<ref name=":0">{{Cite journal|last1=Cidade|first1=Giovanne|last2=Fortier|first2=Daniel|last3=Hsiou|first3=Annie|date=2018-12-01|title=The crocodylomorph fauna of the cenozoic of South America and its evolutionary history: A review|url=https://www.researchgate.net/publication/329960611|journal=Journal of South American Earth Sciences|volume=90|pages=392–411|doi=10.1016/j.jsames.2018.12.026|s2cid=134902094}}</ref><ref name=":2">{{Cite journal|last1=Moreno-Bernal|first1=Jorge W.|last2=Head|first2=Jason|last3=Jaramillo|first3=Carlos A.|date=2016-05-03|title=Fossil Crocodilians from the High Guajira Peninsula of Colombia: Neogene faunal change in northernmost South America|journal=Journal of Vertebrate Paleontology|volume=36|issue=3|pages=e1110586|doi=10.1080/02724634.2016.1110586|s2cid=130332367|issn=0272-4634}}</ref> and from the Oligo-Miocene boundary [[Pirabas Formation]] of coastal Brazil,<ref name=":1" /> ''Gryposuchus'' and ''Ikanogavialis'' persist into the Middle Miocene, with the freshwater-adapting ''Gryposuchus'' expanding throughout the [[Pebas Formation|Pebas mega-wetlands]] into inland Peru and Argentina. In the Late Miocene, ''Gryposuchinae'' diversity explodes, with ''Gryposuchus'' and ''Ikanogavialis'' being joined by ''Hesperogavialis'', of Venezuela and Brazil, ''Piscogavialis'' of coastal Peru, and ''Aktiogavialis'', re-appearing in the fossil record once more, also in Venezuela. At this point, five of the seven genera are present in the Late Miocene, with four genera overlapping in the [[Urumaco formation|Urumaco Formation]] of Venezuela alone, a particular hotspot for crocodilian diversity in the Miocene. Based on the deposits in which they were found, most genera of gryposuchines were solely estuarine, coastal or marine-dwelling; only the genera ''Gryposuchus'' and ''Hesperogavialis'' had some level of freshwater presence. On the flipside, whereas most gryposuchines were restricted to a certain coastal region and time period, ''Gryposuchus'' enjoyed a continent wide distribution, spread from Andeo-Venezuelan drainage basin to Argentina from the Middle Miocene onwards. Additionally, whereas the other genera had one or two species each, ''Gryposuchus'' had five, one of which (''G. croizati'') was the largest of the superfamily on record, at an estimated length of 10m.<ref>{{Cite journal|last1=Cidade|first1=Giovanne|last2=Fortier|first2=Daniel|last3=Hsiou|first3=Annie|date=2018-12-01|title=The crocodylomorph fauna of the cenozoic of South America and its evolutionary history: A review|url=https://www.researchgate.net/publication/329960611|journal=Journal of South American Earth Sciences|volume=90|pages=392–411|doi=10.1016/j.jsames.2018.12.026|s2cid=134902094}}</ref>

At the Miocene/Pliocene boundary, all gryposuchines, and thus the entire superfamily of ''Gavialoidae''Gavialoidea, along with the first wave of [[Crocodyloidea|crocodyloids]] (''Brasilosuchus'' and ''Charactosuchus'', which also colonized during the Miocene'')'' were likely extirpated from South America, with ''[[Caimaninae]]'' undergoing a severe reduction in size and diversity as well. This was likely due to the continuing elevation of the northern sections of the Andes chain reshaping the future Amazonian drainage system, re-rerouting flow to the Venezuelan Caribbean to the much cooler Atlantic, and transforming the mega-wetlands into a fully developed riverine system. The co-current aridification of the continental interior, and isolation of the peripheral wetland basins, also restricted the space and food resources of these large, food intensive specialist crocodilians, and has thus also been suggested as an essential factor in their extinction.<ref name=":2" /><ref>{{Cite journal|last1=Cidade|first1=Giovanne|last2=Fortier|first2=Daniel|last3=Hsiou|first3=Annie|date=2018-12-01|title=The crocodylomorph fauna of the cenozoic of South America and its evolutionary history: A review|url=https://www.researchgate.net/publication/329960611|journal=Journal of South American Earth Sciences|volume=90|pages=392–411|doi=10.1016/j.jsames.2018.12.026|s2cid=134902094}}</ref><ref>{{Cite web|url=https://www.sciencedaily.com/releases/2013/05/130521121323.htm|title=Fourteen closely related crocodiles existed around 5 million years ago|website=ScienceDaily|language=en|access-date=2020-04-19}}</ref> Several other [[Gavialidae|gavialid]] taxa also went extinct globally, suggesting a major global climate change event. However, there may be evidence that ''Piscogavialis'' survived this mass extinction, persisting on the Pacific coast of Pliocene Peru for a few million more years.<ref>{{Cite journal|last1=Salas-Gismondi|first1=Rodolfo|last2=Moreno-Bernal|first2=Jorge W.|last3=Scheyer|first3=Torsten M.|last4=Sánchez-Villagra|first4=Marcelo R.|last5=Jaramillo|first5=Carlos|date=2019-06-18|title=New Miocene Caribbean gavialoids and patterns of longirostry in crocodylians|journal=Journal of Systematic Palaeontology|volume=17|issue=12|pages=1049–1075|doi=10.1080/14772019.2018.1495275|s2cid=91495532|issn=1477-2019}}</ref> Furthermore, crocodyloids would recolonize South America via the African ''[[Crocodylus falconensis|Crocodylus]]'' in the early Pliocene,<ref name=":2" /> whereas gryposuchines would only re-appear in the fossil record six million years later, as [[Ikanogavialis|"''Ikanogavialis''" ''papuensis'']], in the Late Pleistocene/Holocene marine sediments of the [[Woodlark Island]], in the [[Solomon Sea]]. Separated by a geographical barrier of at least 10,000&nbsp;km, this gavialoid had presumably reached [[Melanesia]] in a similar fashion as ''[[Brachylophus]]'' and ''[[Lapitiguana]]'' iguanas, being carried by Pacific oceanic currents. Found in association with [[dugong]]s and [[sea turtle]]s, "''"Ikanogavialis" papuensis''" was a marine animal like its ancestors, a 2-3 meter long coastal piscivore so far known only from [[Woodlark Island|Murua]]. Like other Pleistocene gharials, the species was presumably was hunted to extinction by humanity.<ref>Molnar, R. E. 1982. A longirostrine crocodilian from Murua (Woodlark), Solomon Sea. Memoirs of the Queensland Museum 20, 675-685.</ref>