Metriorhynchidae

{{Short description|Extinct family of reptiles}} {{Automatic taxobox | name = Metriorhynchids | fossil_range = Middle Jurassic-Early Cretaceous, {{fossil_range|168|125}} | image = Cricosaurus albersdoerferi.jpg | image_upright = 1.2 | image_caption = Fossil of ''Cricosaurus'', Museum Eichstaett | taxon = Metriorhynchidae | authority = Fitzinger, 1843 | subdivision_ranks = Genera | subdivision = *{{extinct}}''Enaliosuchus'' *{{extinct}}''Neustosaurus'' *{{extinct}}'''Metriorhynchinae''' Lydekker, 1888 **{{extinct}}''Enalioetes'' **{{extinct}}''Gracilineustes'' **{{extinct}}''Metriorhynchus'' **{{extinct}}''Thalattosuchus'' **{{extinct}}'''Rhacheosaurini''' Young ''et al.'', 2011 ***{{extinct}}''Cricosaurus'' ***{{extinct}}''Maledictosuchus'' ***{{extinct}}''Rhacheosaurus'' *{{extinct}}'''Geosaurinae''' Bonaparte, 1845 **{{extinct}}''Neptunidraco'' **{{extinct}}'''Geosaurini''' Bonaparte, 1845 ***{{extinct}}''Aggiosaurus'' ***{{extinct}}''Dakosaurus'' ***{{extinct}}''Purranisaurus'' ***{{extinct}}''Torvoneustes'' ***{{extinct}}''Tyrannoneustes'' ***{{extinct}}'''Geosaurina''' Bonaparte, 1845 ****{{extinct}}''Geosaurus'' ****{{extinct}}''Ieldraan'' ***{{extinct}}'''Plesiosuchina''' Young ''et al.'', 2014 ****{{extinct}}''Plesiosuchus'' ****{{extinct}}''Suchodus''

| synonyms = *Geosauridae Andrews, 1913<ref name="Andrews, 1913">{{Cite book|last1=Andrews |first1=CW. |date=1913 |title=A descriptive catalogue of the marine reptiles of the Oxford Clay, Part Two |location=London |publisher=British Museum (Natural History) |page=206}}</ref> }} thumb|Life restoration of members of the Metriorhynchinae compared to a human '''Metriorhynchidae''' is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period (Bajocian to early Aptian<ref>{{cite journal|author=Alfio A. Chiarenza |author2=Davide Foffa |author3=Mark T. Young |author4=Gianni Insacco |author5=Andrea Cau |author6=Giorgio Carnevale |author7=Rita Catanzariti |year=2015 |title=The youngest record of metriorhynchid crocodylomorphs, with implications for the extinction of Thalattosuchia |journal=Cretaceous Research |volume=56 |pages=608–616 |doi=10.1016/j.cretres.2015.07.001 |bibcode=2015CrRes..56..608C |hdl=2318/1537833 |hdl-access=free }}</ref>) of Europe, North America and South America. The name Metriorhynchidae was coined by the Austrian zoologist Leopold Fitzinger in 1843.<ref name="Fitzinger, 1843">Fitzinger LJFJ. 1843. ''Systema Reptilium''. Wien: Braumüller et Seidel, 106 pp.</ref> The group contains two subfamilies, the Metriorhynchinae and the Geosaurinae.<ref name=YoungAndrade09>{{cite journal|author1=Mark T. Young |author2=Marco Brandalise de Andrade |year=2009 |title=What is ''Geosaurus''? Redescription of ''Geosaurus giganteus'' (Thalattosuchia: Metriorhynchidae) from the Upper Jurassic of Bayern, Germany |journal=Zoological Journal of the Linnean Society |volume=157 |issue=3 |pages=551–585 |doi=10.1111/j.1096-3642.2009.00536.x |doi-access=free }}</ref><ref name=Youngetal10>{{cite journal|author1=Mark T. Young |author2=Stephen L. Brusatte |author3=Marcello Ruta |author4=Marco Brandalise de Andrade |year=2010 |title=The evolution of Metriorhynchoidea (Mesoeucrocodylia, Thalattosuchia): an integrated approach using geometrics morphometrics, analysis of disparity and biomechanics |journal=Zoological Journal of the Linnean Society |issue=4 |volume=158 |pages=801–859 |doi=10.1111/j.1096-3642.2009.00571.x |doi-access=free }}</ref> They represent the most marine adapted of all archosaurs.

==Description== Metriorhynchids are fully aquatic crocodyliforms. Their forelimbs were small and paddle-like, and unlike living crocodylians, they lost their osteoderms ("armour scutes"). Their body shape maximised hydrodynamy (swimming efficiency), as they did have a shark-like tail fluke.<ref name="Fraas, 1902">{{cite journal | author = Fraas E | year = 1902 | title = Die Meer-Krocodilier (Thalattosuchia) des oberen Jura unter specieller Berücksichtigung von ''Dacosaurus'' und ''Geosaurus'' | journal = Palaeontographica | volume = 49 | pages = 1–72 }}</ref> Like ichthyosaurs and plesiosaurs, metriorhynchids developed smooth, scaleless skin.<ref>{{Cite journal|last1=Spindler|first1=Frederik|last2=Lauer|first2=René|last3=Tischlinger|first3=Helmut|last4=Mäuser|first4=Matthias|date=2021-07-05|title=The integument of pelagic crocodylomorphs (Thalattosuchia: Metriorhynchidae)|url=https://palaeo-electronica.org/content/2021/3399-metriorhynchid-skin|journal=Palaeontologia Electronica|language=English|volume=24|issue=2|pages=1–41|doi=10.26879/1099|issn=1094-8074|doi-access=free}}</ref> However, unlike those marine reptiles, they were poikilothermic with little to no endothermic ability.<ref>{{Cite journal |last=Séon |first=Nicolas |last2=Vincent |first2=Peggy |last3=Delsett |first3=Lene L. |display-authors=et al. |date=April 16, 2025 |title=Reassessment of body temperature and thermoregulation strategies in Mesozoic marine reptiles |url=https://www.cambridge.org/core/journals/paleobiology/article/reassessment-of-body-temperature-and-thermoregulation-strategies-in-mesozoic-marine-reptiles/5DB88592AC69236250A516904E20FEC4 |journal=Paleobiology |pages=1-21}}</ref>

Metriorhynchids were the only group of archosaurs to become fully adapted to the marine realm, becoming pelagic in lifestyle.<ref name="Steel, 1973">Steel R. 1973. ''Crocodylia. Handbuch der Paläoherpetologie, Teil 16''. Stuttgart: Gustav Fischer Verlag,116 pp.</ref> With tail flukes, reduced limb musculature, and long bones histologically comparable to other obligately aquatic animals, they were almost certainly incapable of terrestrial locomotion; combined with an unusually tall hip opening, as also seen in other obligately aquatic reptiles including the viviparous ''Keichousaurus'', these characters suggest that metriorhynchids gave live birth.<ref name="vivi">{{cite journal | first1 = Y. | last1 = Herrera | first2 = M.S. | last2 = Fernandez | first3 = S.G. | last3 = Lamas | first4 = L. | last4 = Campos | first5 = M. | last5 = Talevi | first6 = Z. | last6 = Gasparini | title = Morphology of the sacral region and reproductive strategies of Metriorhynchidae: a counter-inductive approach | doi = 10.1017/S1755691016000165 | journal = Earth and Environmental Science Transactions of the Royal Society of Edinburgh | volume = 106 | issue = 4 | pages = 247–255 | date = 2017| doi-access = free | hdl = 11336/66599 | hdl-access = free }}</ref> A fossil of a pregnant ''Dakosaurus'' female recovered from the Late Jurassic plattenkalk, Bavaria, preserves the complete skeleton of a neonate with small, paddle-like forelimbs unsuited for walking on land, similar to those of adults, further supporting live birth in metriorhynchids.<ref>{{cite book|year=2019|author=Spindler, Frederik|url=https://www.palaeontologie.geowissenschaften.uni-muenchen.de/pdfs/palges2019_abstracts.pdf#page=141|title=Live Birth in a Jurassic Marine Crocodile [abstract]. In: Abstracts of the 90th Annual Meeting of the Paläontologische Gesellschaft|publisher= SNSB - BSPG, München|page=141|isbn=978-3-946705-07-9|archive-url=https://web.archive.org/web/20230517045802/https://www.palaeontologie.geowissenschaften.uni-muenchen.de/pdfs/palges2019_abstracts.pdf#page=141|archive-date=2023-05-17|url-status=live}}</ref><ref>{{cite book|year=2019|author=Spindler, Frederik|url=https://www.palaeontologie.geowissenschaften.uni-muenchen.de/pdfs/palges2019_abstracts.pdf#page=10|title=When Bavaria was the Ancient Caribbean – Plattenkalk Fossil Treasures from Painten [abstract]. In: Abstracts of the 90th Annual Meeting of the Paläontologische Gesellschaft|publisher= SNSB - BSPG, München|page=10|isbn=978-3-946705-07-9|archive-url=https://web.archive.org/web/20230517045802/https://www.palaeontologie.geowissenschaften.uni-muenchen.de/pdfs/palges2019_abstracts.pdf#page=10|archive-date=2023-05-17|url-status=live}}</ref> Recent research posits that despite their successful adaptation to a pelagic lifestyle, basal metriorhynchids were uniquely disadvantaged among aquatic tetrapods in evolving into sustained swimmers due to little to no posterodorsal retraction of the external nares (unlike other reptilian groups such as mesosaurs, phytosaurs, thalattosaurians, saurosphargids, ichthyosauriforms, sauropterygians, pleurosaurids or mosasauroids, as well as mammalian cetaceans or sirenians).<ref name="Young2020">{{cite journal|author1= Young, M.T.|author2= Sachs, S.|author3= Abel, P.|author4= Foffa, D.|author5= Herrera, Y.|author6= Kitson, J.J.N.|year= 2020|title= Convergent evolution and possible constraint in the posterodorsal retraction of the external nares in pelagic crocodylomorphs |journal= Zoological Journal of the Linnean Society |volume= 189|issue= 2|pages= 494–520|doi= 10.1093/zoolinnean/zlaa021|doi-access= free|hdl= 11336/137182|hdl-access= free}}</ref> The family has a wide geographic distribution, with material found in Argentina, Chile, Cuba, England, France, Germany, Italy, Mexico, Poland, Russia, Switzerland and Czech Republic.<ref name="Steel, 1973" /><ref name="Youngetal10" /><ref name=Madzia2021>{{cite journal|author=Daniel Madzia, Sven Sachs, Mark T. Young, Alexander Lukeneder, Petr Skupien|year=2021|url=https://www.app.pan.pl/archive/published/app66/app008012020.pdf|title=Evidence of two lineages of metriorhynchid crocodylomorphs in the Lower Cretaceous of the Czech Republic|journal=Acta Palaeontologica Polonica|volume=66|issue=2|page=1-11|doi=10.4202/app.00801.2020|archive-url=https://web.archive.org/web/20210521113300/https://www.app.pan.pl/archive/published/app66/app008012020.pdf|archive-date=2021-05-21}}</ref>

==Classification== Phylogenetic analyses published during the 2000s cast doubt on the idea that many traditional metriorhynchid genera formed natural groups (i.e., include all descendants of a common ancestor). The traditional species of ''Geosaurus'',<ref name="Young, 2007"/><ref name="Wilkinson et al., 2008"/><ref name="Mueller-Töwe, 2005"/> ''Dakosaurus''<ref name="Young, 2007"/> and ''Cricosaurus''<ref name="Young, 2007"/> were found to represent unnatural groups, and the species traditionally classified in these genera were reshuffled in a study published in November 2009 by Mark T. Young and Marco Brandalise de Andrade.<ref name=YoungAndrade09/> The monophyly of ''Metriorhynchus''<ref name="Young, 2007">{{cite journal | author = Young MT | year = 2007 | title = The evolution and interrelationships of Metriorhynchidae (Crocodyliformes, Thalattosuchia) | doi = 10.1080/02724634.2007.10010458| journal = Journal of Vertebrate Paleontology | volume = 27 | issue = 3| page = 170A }}</ref><ref name="Wilkinson et al., 2008">{{cite journal |vauthors=Wilkinson LE, Young MT, Benton MJ | year = 2008 | title = A new metriorhynchid crocodilian (Mesoeucrocodylia: Thalattosuchia) from the Kimmeridgian (Upper Jurassic) of Wiltshire, UK. | journal = Palaeontology | volume = 51 | issue = 6| pages = 1307–1333 | doi=10.1111/j.1475-4983.2008.00818.x| doi-access = free | bibcode = 2008Palgy..51.1307W }}</ref><ref name="Gasparini''et al.'', 2006">{{cite journal |vauthors=Gasparini Z, Pol D, Spalletti LA | year = 2006 | title = An unusual marine crocodyliform from the Jurassic-Cretaceous boundary of Patagonia | journal = Science | volume = 311 | issue = 5757| pages = 70–73 | doi=10.1126/science.1120803| pmid = 16282526 | bibcode = 2006Sci...311...70G | s2cid = 10312971 | doi-access = free | hdl = 11336/73480 | hdl-access = free }}</ref> and ''Teleidosaurus''<ref name="Young, 2007"/><ref name="Mueller-Töwe, 2005">{{cite journal | author = Mueller-Töwe IJ | year = 2005 | title = Phylogenetic relationships of the Thalattosuchia | journal = Zitteliana | volume = A45 | pages = 211–213 }}</ref> is also unsupported, and the species of these genera are pending reclassification.<ref name=YoungAndrade09/>

The classification presented by Young and Andrade in 2009 was approved in later studies of the Metriorhynchidae.<ref name="Youngetal10"/><ref name=Neptunidraco>{{cite journal|author1=Andrea Cau |author2=Federico Fanti |year=2011 |title=The oldest known metriorhynchid crocodylian from the Middle Jurassic of North-eastern Italy: ''Neptunidraco ammoniticus'' gen. et sp. nov. |journal=Gondwana Research |volume=19 |issue=2 |pages=550–565 |doi=10.1016/j.gr.2010.07.007|bibcode=2011GondR..19..550C }}</ref><ref name=Rhacheosaurini>{{cite journal|author1=Mark T. Young |author2=Mark A. Bell |author3=Stephen L. Brusatte |year=2011 |title=Craniofacial form and function in Metriorhynchidae (Crocodylomorpha: Thalattosuchia): modelling phenotypic evolution with maximum-likelihood methods |journal=Biology Letters |volume=7 |issue=6 |pages=913–916 |doi=10.1098/rsbl.2011.0357 |pmid=21543396 |pmc=3210659}}</ref> Metriorhynchidae is a node-based taxon defined in the ''PhyloCode'' by Mark T. Young and colleagues in 2024 as "the smallest clade within Metriorhynchoidea containing ''Thalattosuchus superciliosus'', ''Gracilineustes leedsi'', ''Metriorhynchus brevirostris'', ''Rhacheosaurus gracilis'', and ''Geosaurus giganteus''" <ref name=Youngetal2024>{{cite journal |doi=10.1093/zoolinnean/zlad165 |title=The history, systematics, and nomenclature of Thalattosuchia (Archosauria: Crocodylomorpha) |date=2024 |last1=Young |first1=Mark T. |last2=Wilberg |first2=Eric W. |last3=Johnson |first3=Michela M. |last4=Herrera |first4=Yanina |last5=De Andrade |first5=Marco Brandalise |last6=Brignon |first6=Arnaud |last7=Sachs |first7=Sven |last8=Abel |first8=Pascal |last9=Foffa |first9=Davide |last10=Fernández |first10=Marta S. |last11=Vignaud |first11=Patrick |last12=Cowgill |first12=Thomas |last13=Brusatte |first13=Stephen L. |journal=Zoological Journal of the Linnean Society |volume=200 |issue=2 |pages=547–617 |doi-access=free }}</ref> The cladogram below follows the topology from the 2020 analyses by Young ''et al.'' and reduced to genera only.<ref name="Young2020" /><ref name="Youngetal.2020">{{cite journal|author=Young, M.T., Brignon, A., Sachs, S., Hornung J.J., Foffa, D., Kitson, J.J.N., Johnson, M.M., Steel, L.|date=November 2020|url=|title=Cutting the Gordian knot: a historical and taxonomic revision of the Jurassic crocodylomorph ''Metriorhynchus''|journal=Zoological Journal of the Linnean Society|volume=192|issue=2|pages=510–553 |doi=10.1093/zoolinnean/zlaa092}}</ref>

{{clade| style=font-size:100%;line-height:85% |label1='''Metriorhynchidae''' |1={{clade |label1='''Metriorhynchinae''' |1={{clade |1=''Thalattosuchus'' |2={{clade |1=''Gracilineustes'' |2={{clade |1=''Maledictosuchus'' |2={{clade |1=''Metriorhynchus'' |label2='''Rhacheosaurini''' |2={{clade |2=''Rhacheosaurus'' |1=''Cricosaurus'' }} }} }} }} }} |label2='''Geosaurinae''' |2={{clade |1=''Neptunidraco'' |2={{clade |label1='''Geosaurini''' |1={{clade |1={{clade |1=''Tyrannoneustes'' |2={{clade |1=''Torvoneustes'' |2='E-clade' |3=''Purranisaurus'' }} }} |2={{clade |1={{clade |1=''Ieldraan'' |2=''Geosaurus'' }} |2={{clade |1=''Dakosaurus'' |2={{clade |1=''Plesiosuchus'' |2=''Suchodus'' }} }} }} }} }} }} }} }}

===List of genera=== The type genus of the family Metriorhynchidae is ''Metriorhynchus'' from the Middle to Late Jurassic.<ref name="Youngetal.2020"/> Other genera included within this family are ''Cricosaurus'', ''Geosaurus'', and ''Dakosaurus''. Though once considered a metriorhynchid, ''Teleidosaurus'' has since been found to be slightly more distantly related to these animals within the superfamily Metriorhynchoidea.<ref>{{cite journal|author=Stéphane Hua|date=May 2020|title=A new specimen of ''Teleidosaurus calvadosii'' (Eudes-Deslongchamps, 1866) (Crocodylia, Thalattosuchia) from the Middle Jurassic of France|journal=Annales de Paléontologie|volume=106|issue=4|doi=10.1016/j.annpal.2020.102423|bibcode=2020AnPal.10602423H }}</ref>

Within this family, the genus ''Neustosaurus'' and ''Enaliosuchus'' are considered ''nomen dubium'' ("doubtful name").<ref name="Buffetaut, 1982b">{{cite journal | author = Buffetaut E | year = 1982 | title = Radiation évolutive, paléoécologie et biogéographie des Crocodiliens mésosuchienes | journal = Mémoires de la Société Géologique de France | volume = 142 | pages = 1–88 }}</ref>

The genus ''Capelliniosuchus'' was once thought to be a metriorhynchid similar to ''Dakosaurus''.<ref name="Simonelli, 1896">{{cite journal | author = Simonelli V | year = 1896 | title = Intoro agli avanzi di coccodrilliano scoperti a San Valentino (provincial di Reggio Emilia) nel 1886 | journal = Atli della Reale Accademia dei Lincei, Series Qunita Rendiconti | volume = 5 | issue = 2| pages = 11–18 }}</ref> However, it was later found to be a mosasaur.<ref>{{Cite journal |last1=Fanti |first1=Federico |last2=Cau |first2=Andrea |last3=Negri |first3=Alessandra |date=2014-05-01 |title=A giant mosasaur (Reptilia, Squamata) with an unusually twisted dentition from the Argille Scagliose Complex (late Campanian) of Northern Italy |url=https://www.sciencedirect.com/science/article/pii/S0195667114000068 |journal=Cretaceous Research |language=en |volume=49 |pages=91–104 |doi=10.1016/j.cretres.2014.01.003 |bibcode=2014CrRes..49...91F |issn=0195-6671|url-access=subscription }}</ref>

{| class="wikitable" align="center" |- ! Genus ! Status ! Author ! Age ! Location ! Description ! Synonyms ! Images |- | *''Aggiosaurus'' | | Ambayrac, 1913 | late Oxfordian | France. |Sometimes considered to be a ''nomen dubium''. | | rowspan="47"| [[Image:Geosaurus BW.jpg|thumb|center|150px|''Cricosaurus suevicus'']] [[Image:Dakosaurus BW.jpg|thumb|center|150px|''Dakosaurus andiniensis'']] [[Image:Metriorhynchus superciliosum.jpg|thumb|center|150px|''Thalattosuchus superciliosus'']] [[Image:Neptunidraco NT.jpg|thumb|center|150px|''Neptunidraco ammoniticus'']] [[Image:Suchodus BW.jpg|thumb|center|150px|'''Metriorhynchus' casamiquelai'']] [[Image:Suchodus durobrivense.jpg|thumb|center|150px|''Suchodus durobrivensis'']] |- | *''Cricosaurus'' | Valid | Wagner, 1858 | middle Oxfordian to upper Valanginian | Argentina, Chile, Cuba, England, France, Germany, Mexico, Russia and Switzerland. | | |- | *''Dakosaurus''<ref name="Quenstedt, 1856">Quenstedt FA. 1856. ''Sonst und Jetzt: Populäre Vortäge über Geologie''. Tübingen: Laupp, 131.</ref> | Valid | von Quenstedt, 1856 | upper Kimmeridgian to lower Berriasian | Argentina, England, France, Germany, Mexico, Poland, Switzerland and possibly Russia. | | *''Dacosaurus'' (''lapsus calami'') |- | *''Enaliosuchus''<ref name="Koken, 1883">{{cite journal | author = Koken E | year = 1883 | title = Die reptilian der norddeutschen unteren Kreide | journal = Zeitschrift der Deutschen Geologischen Gesellschaft | volume = 35 | pages = 735–827 }}</ref> | ''nomen dubium''<ref name="Sachs et al., 2020">{{cite journal | author = Sachs S, Young MT, Hornung JJ | year = 2020 | title = The enigma of Enaliosuchus, and a reassessment of the Lower Cretaceous fossil record of Metriorhynchidae | journal = Cretaceous Research | volume = 114 | article-number = 104479 | doi = 10.1016/j.cretres.2020.104479 | bibcode = 2020CrRes.11404479S | hdl = 20.500.11820/c52d1d56-1bf3-4aae-b2e1-38c85eed44fa | s2cid = 218996914 | url = https://www.pure.ed.ac.uk/ws/files/143193289/171._Mark_Young.pdf | hdl-access = free }}</ref> | Koken, 1883 | Valanginian | Germany. | |- | *''Geosaurus''<ref name="Cuvier, 1824">Cuvier G. 1824. Sur les ossements fossiles de crocodiles, 5. In: Dufour & D'Occagne, eds. ''Recherches sur les ossements fossiles, 2nd édition''. Paris: 143-160</ref> | Valid | Cuvier, 1824 | upper Kimmeridgian to upper Valanginian | France, Germany, Italy and Switzerland. | | *''Brachytaenius'' *''Halilimnosaurus'' |- | *''Gracilineustes''<ref name="Youngetal.2010">{{cite journal | author = Young Mark T., Brusatte Stephen L., Ruta M., Andrade Marco B. | year = 2009 | title = The evolution of Metriorhynchoidea (Mesoeucrocodylia, Thalattosuchia): an integrated approach using geometrics morphometrics, analysis of disparity and biomechanics | journal = Zoological Journal of the Linnean Society | volume = 158 | issue = 4| pages = 801–859 | doi=10.1111/j.1096-3642.2009.00571.x| doi-access = free }}</ref> | Valid | Young ''et al.'', 2010 | middle Callovian to lower Kimmeridgian | England and France. | | |- | *''Maledictosuchus'' | Valid | Parrilla-Bel ''et al.'', 2013 | middle Callovian to Kimmeridgian | Spain and Mexico. | | |- | *''Metriorhynchus'' | Valid | von Meyer, 1832 | lower Kimmeridgian. | France. | | *''Metiorychus'' (''lapsus calami'') |- | *''Neptunidraco''<ref name="Neptunidraco"/> | Valid | Cau & Fanti, 2011 | earliest Bathonian | Italy. | | |- | *''Neustosaurus'' | ''nomen dubium'' | | Valanginian | | — potential senior synonym of ''Enaliosuchus'' | |- | *''Plesiosuchus'' | Valid | Owen, 1884 | late Kimmeridgian to early Tithonian | England and possibly Spain. | | |- | *''Purranisaurus'' | Valid | Rusconi, 1948 | upper Tithonian | Argentina and Chile. | | |- | *''Rhacheosaurus'' | Valid | von Meyer, 1831 | lower Tithonian | Germany. | | |- | *''Suchodus'' | Valid | Lydekker, 1890 | middle Callovian to lower Oxfordian | England and France. | | |- | *''Thalattosuchus'' | Valid | Young ''et al.'', 2020 | lower Callovian to lower Oxfordian | England and France. | | |- | *''Torvoneustes''<ref name=Aetal10>{{cite journal |last=Andrade |first=M.B.D. |author2=Young, M.T. |author3=Desojo, J.B. |author4= Brusatte, S.L. |year=2010 |title=The evolution of extreme hypercarnivory in Metriorhynchidae (Mesoeucrocodylia: Thalattosuchia) based on evidence from microscopic denticle morphology |journal=Journal of Vertebrate Paleontology |volume=30 |issue=5 |pages=1451–1465 |doi=10.1080/02724634.2010.501442|bibcode=2010JVPal..30.1451D |s2cid=83985855 |hdl=11336/69039 |hdl-access=free }}</ref> | Valid | Andrade ''et al.'', 2010 | Kimmeridgian to Tithonian | England. | | |- | *''Tyrannoneustes'' | Valid | Young ''et al.'', 2013 | Callovian | England. | | |}

==Subclades==

Summary of the phylogenetic definitions of '''metriorhynchid''' subclades shown in the classification section. These are based on Young and colleagues 2024.<ref name=Youngetal2024/>

{| class="wikitable sortable" align="center" width="100%" ! Name ! Named by ! Definition |- | '''Dakosaurina''' | Young ''et al.'', 2024<ref name=Youngetal2024/> | The largest clade within Metriorhynchidae containing ''Dakosaurus maximus'', but not ''Metriorhynchus brevirostris'', ''Geosaurus giganteus'', ''Plesiosuchus manselii'', and ''Torvoneustes carpenteri''. |- | '''Geosaurina''' | Bonaparte, 1845 | The largest clade within Metriorhynchidae containing ''Geosaurus giganteus'', but not ''Metriorhynchus brevirostris'', ''Plesiosuchus manselii'', ''Torvoneustes carpenteri'', and ''Dakosaurus maximus''. |- | '''Geosaurinae''' | Bonaparte, 1845 | The largest clade within Metriorhynchidae containing ''Geosaurus giganteus'', but not ''Rhacheosaurus gracilis'', ''Metriorhynchus brevirostris'', and ''Gracilineustes leedsi''. |- | '''Geosaurini''' | Bonaparte, 1845 | The smallest clade within Metriorhynchidae containing ''Tyrannoneustes lythrodectikos'', ''Geosaurus giganteus'', ''Torvoneustes carpenteri'', and ''Dakosaurus maximus''. |- | '''Metriorhynchidae''' | Fitzinger, 1843 | The smallest clade within Metriorhynchoidea containing ''Thalattosuchus superciliosus'', ''Gracilineustes leedsi'', ''Metriorhynchus brevirostris'', ''Rhacheosaurus gracilis'', and ''Geosaurus giganteus''. |- | '''Metriorhynchinae''' | Lydekker, 1888 | The smallest clade within Metriorhynchidae containing ''Rhacheosaurus gracilis'', ''Metriorhynchus brevirostris'', and ''Gracilineustes leedsi''. |- | '''Plesiosuchina''' | Young ''et al.'',2014 | The largest clade within Metriorhynchidae containing ''Plesiosuchus manselii'', but not ''Metriorhynchus brevirostris'', ''Geosaurus giganteus'', ''Torvoneustes carpenteri'', and ''Dakosaurus maximus''. |- | '''Rhacheosaurini''' | Young ''et al.'', 2011 | The largest clade within Metriorhynchidae containing ''Rhacheosaurus gracilis'', but not ''Metriorhynchus brevirostris'' and ''Gracilineustes leedsi''. |- |}

==See also== {{Portal|Paleontology}} *List of marine reptiles

==References== {{Reflist|2}}

==External links== * {{cite web|url=http://palaeos.com/vertebrates/crocodilia/crocodyliformes.html#Metriorhynchidae|title=Crocodilia: Crocodyliformes (Gobiosuchids, Teleosaurs & Metriorhynchids)|website=Palaeos|archive-url=https://web.archive.org/web/20230217000801/http://palaeos.com/vertebrates/crocodilia/crocodyliformes.html#Metriorhynchidae|archive-date=2023-02-17|url-status=live}}

Category:Thalattosuchia Category:Middle Jurassic crocodylomorphs Category:Early Cretaceous crocodylomorphs Category:Pseudosuchian families Category:Prehistoric marine crocodylomorphs Category:Middle Jurassic first appearances Category:Early Cretaceous extinctions Category:Late Jurassic crocodylomorphs