Benthosuchus

{{Short description|Extinct genus of amphibians}} {{Automatic taxobox | fossil_range = [[Early Triassic]], {{fossilrange|251|247}} | image = Бентозух2021.jpg | image_caption = Skull of ''Benthosuchus sushkini'' | parent_authority = Efremov, 1940 | taxon = Benthosuchus | authority = [[Ivan Yefremov|Efremov]], 1937<ref>{{cite journal|author=Igor Novikov|date=July 2012|title=New data on trematosauroid labyrinthodonts of Eastern Europe: 4. Genus Benthosuchus Efremov, 1937|journal=Paleontological Journal|volume=46|issue=4|doi=10.1134/S0031030112040089}}</ref> | subdivision_ranks = Species | subdivision = * {{extinct}}''B. sushkini'' (Efremov, 1929 [originally ''[[Benthosaurus]] sushkini'']) ([[Type species|type]]) * {{extinct}}''B. korobkovi'' Ivachnenko, 1972 * {{extinct}}''B. bashkiricus'' Otschev, 1972 * {{extinct}}''B. gusevae'' Novikov, 2012 * {{extinct}}''B. lukyanovi '' Morkovin, 2020 }} [[Image:Benthosuchus2DB2small.jpg|thumb|left|Life restoration of ''Benthosuchus sushkini'']] [[File:Benthosuchus korobkovi.JPG|thumb|left|Underside of the skull of the species ''Benthosuchus korobkovi'' showing double rows of small teeth and large fangs on the front palate]]

'''''Benthosuchus''''' (meaning "deep water crocodile") is an [[extinct]] [[genus]] of [[temnospondyli|temnospondyl]] [[amphibian]] from the [[Early Triassic]] of [[Russia]]. It was primarily aquatic, living in rivers and lakes. Multiple species are known, with the largest reaching about 2.5 meters in length.

Russian paleontologist [[Ivan Yefremov]] [Efremov] called the genus ''Benthosaurus'' "deep water lizard" (from Ancient Greek βένθος (''benthos'') "depth, deep water") in his original 1929 description, "in view of its clearly indicated adaptation to life in deep water" shown by "the position of the orbits and the flatness of the skull." The type species ''B. sushkini'' honored his late teacher [[Petr Sushkin]]. The generic name was preoccupied by ''Benthosaurus'' Goode & Bean, 1886, a fish, and he renamed the genus ''Benthosuchus'' ("deep water crocodile") in 1937.<ref name=Efremov1929>Efremov, I. A. (1929). ''Benthosaurus sushkini'', ein neuer Labyrinthodont der permotriassischen Ablagerungen der Sharschenga Flusses. ''Bulletin of the Academy of Sciences of the USSR'' '''8''':747-770. [English translation: https://paleoglot.org/files/Efremov%201929b.pdf]</ref><ref name=Efremov1937>Efremov, I.A. (1937). On the Stratification of Continental Permian and Triassic the Soviet Union Based on the Terrestrial Vertebrate Fauna. ''Doklady Akademii Nauk SSSR. Nov. Ser. 16(2)'': 125–132.</ref>

''Benthosuchus'' has traditionally been considered a member of the temnospondyl superfamily [[Trematosauroidea]], and the family Benthosuchidae was established in 1940 to include ''Benthosuchus'' and the related trematosauroid ''[[Thoosuchus]]''. Some recent [[phylogenetic]] studies have removed ''Benthosuchus'' from Trematosauroidea entirely, placing it as a closer relative of [[Mastodonsauroidea]], another group of Triassic temnospondyls. Other studies retain ''Benthosuchus'' within Trematosauroidea, but since ''Benthosuchus'' and ''Thoosuchus'' have successively [[basal (phylogenetics)|basal]] positions on these trees they form a [[paraphyletic]] grouping, not a valid clade.<ref name=DY03>{{cite journal |last=Damiani |first=R.J. |author2=Yates, A.M. |year=2003 |title=The Triassic amphibian ''Thoosuchus yakovlevi'' and the relationships of the Trematosauroidea (Temnospondyli: Stereospondyli) |journal=Records of the Australian Museum |volume=55 |issue=3 |pages=331–342 |url=http://australianmuseum.com/Uploads/Journals/17964/1388_complete.pdf |doi=10.3853/j.0067-1975.55.2003.1388 |archive-date=2014-05-04 |access-date=2012-04-04 |archive-url=https://web.archive.org/web/20140504172139/http://australianmuseum.com/Uploads/Journals/17964/1388_complete.pdf |url-status=dead }}</ref> Benthosuchidae was widely considered to be a [[monotypic]] family containing only ''Benthosuchus'', until the discovery of the related ''[[Kwatisuchus]]'' in 2024.<ref>{{Cite journal |last=Pinheiro |first=Felipe L. |last2=Eltink |first2=Estevan |last3=Paes‐Neto |first3=Voltaire D. |last4=Machado |first4=Arielli F. |last5=Simões |first5=Tiago R. |last6=Pierce |first6=Stephanie E. |date=2024-01-19 |title=Interrelationships among Early Triassic faunas of Western Gondwana and Laurasia as illuminated by a new South American benthosuchid temnospondyl |url=http://dx.doi.org/10.1002/ar.25384 |journal=The Anatomical Record |doi=10.1002/ar.25384 |issn=1932-8486|url-access=subscription }}</ref>

==Description== ''Benthosuchus'' [[skull]] is about 0.75 m long (it is comparatively short in young individuals but lengthens with age), and the overall body length is about 2.5 m. It existed in widely overflowing rivers of the [[East Russian Depression]].<ref>{{Cite web|url=https://encyclopedia2.thefreedictionary.com/Benthosuchus|title=Benthosuchus|access-date=Oct 16, 2020|via=The Free Dictionary}}</ref>

==Phylogeny== ''Benthosuchus'' is traditionally considered a close relative of a group of temnospondyls called [[capitosaurid]]s. In particular, it bears a close resemblance to the capitosaurid ''[[Wetlugasaurus]]''. Many of the early large-scale phylogenetic analyses of temnospondyls place ''Benthosuchus'' within a [[clade]] called [[Capitosauria]]. However, more recent analyses such as that of Fortuny ''et al.'' (2011) recover ''Benthosuchus'' within another clade called [[Trematosauria]]. Occasionally it is grouped near the trematosaurid family [[Trematosauridae]] as a [[basal (phylogenetics)|basal]] member of the group [[Trematosauroidea]].<ref name=SS09>{{cite journal |last=Shishkin |first=M.A. |author2=Sulej, T. |year=2009 |title=Early Triassic temnospondyls of the Czatkowice 1 tetrapod assemblage |journal=Palaeontologica Polonica |volume=65 |pages=31–77 |url=http://palaeontologia.pan.pl/PP65/PP65_031-078.pdf |access-date=2012-08-02 |archive-date=2012-03-01 |archive-url=https://web.archive.org/web/20120301040441/http://palaeontologia.pan.pl/PP65/PP65_031-078.pdf |url-status=dead }}</ref> Fortuny ''et al.'' found that ''Benthosuchus'' positioned outside Trematosauroidea as a more basal trematosaurian. Below is a [[cladogram]] from Fortuny ''et al.'' (2011) showing the [[phylogenetic]] placement of ''Benthosuchus'':<ref name=FGS11>{{Cite journal | last1 = Fortuny | first1 = J. | last2 = Galobart | first2 = À. | last3 = Santisteban | first3 = C. D. | doi = 10.4202/app.2010.0025 | title = A New Capitosaur from the Middle Triassic of Spain and the Relationships within the Capitosauria | journal = Acta Palaeontologica Polonica | volume = 56 | issue = 3 | pages = 553 | year = 2011 | doi-access = free }}</ref> {{clade| style=font-size:100%;line-height:85% |label1=[[Stereospondyli]] |1={{clade |1=''[[Lydekkerina huxleyi]]'' |label2=[[Rhinesuchidae]] |2={{clade |1=''[[Rhineceps nyasaensis]]'' |2=''[[Uranocentrodon senekalensis]]''}} |3={{clade |label1=[[Capitosauria]] |1={{clade |1=''[[Wetlugasaurus angustifrons]]'' |2={{clade |1={{clade |1=''[[Odenwaldia heidelbergensis]]'' |2=''[[Vladlenosaurus alexeyevi]]''}} |2={{clade |1={{clade |1={{clade |1=''[[Edingerella madagascariensis]]'' |2=''[[Watsonisuchus]] spp.''}} |2={{clade |1=''[[Xenotosuchus africanus]]'' |2={{clade |1=''[[Cherninia denwai]]'' |2={{clade |1=''[[Paracyclotosaurus crookshanki]]'' |2={{clade |1={{clade |1=''[[Stanocephalosaurus pronus]]'' |2=''[[Stanocephalosaurus birdi]]''}} |2={{clade |1=''[[Procyclotosaurus stantonensis]]'' |2={{clade |1=''[[Eocyclotosaurus]] spp.'' |2=''[[Quasicyclotosaurus campi]]''}} }} }} }} }} }} }} |2={{clade |1=''[[Parotosuchus orenburgensis]]'' |2={{clade |1=''[[Calmasuchus acri]]'' |2={{clade |1={{clade |1=''[[Cyclotosaurus robustus]]'' |2=''[[Tatrasuchus wildi]]''}} |2={{clade |1=''[[Eryosuchus garjainovi]]'' |2=''[[Mastodonsaurus giganteus]]''}} }} }} }} }} }} }} |label2=[[Trematosauria]] |2={{clade |1='''''Benthosuchus sushkini''''' |label2=[[Trematosauroidea]] |2={{clade |1=''[[Thoosuchus yakovlevi]]'' |2={{clade |1=''[[Angusaurus]] spp.'' |2=''[[Trematosaurus brauni]]'' }} }} }} }} }} }}

Cladogram after Novikov (2018) with only Early Triassic Eastern Europe taxa included:<ref name=Novikov2018>{{cite book|author=Novikov A.V.|year=2018|url=https://new.ras.ru/upload/iblock/7de/j85vtubof3mlf81izrqq9u9oh9eb5lrh.pdf|title=Early Triassic amphibians of Eastern Europe: evolution of dominant groups and peculiarities of changing communities|publisher=Moscow: RAS|page=138|lang=ru|isbn=978-5-906906-71-7|archive-date=December 8, 2023|access-date=February 8, 2024|archive-url=https://web.archive.org/web/20231208092959/https://new.ras.ru/upload/iblock/7de/j85vtubof3mlf81izrqq9u9oh9eb5lrh.pdf|url-status=bot: unknown}}</ref>

{{cladex| style=font-size:100%;line-height:100% |label1=[[Temnospondyli]] |1= {{Barlabel|size=24|at=2|label=[[Lydekkerinidae]]|colour=green|style=font-size:100% |cladogram= {{cladex |1=''[[Luzocephalus]]'' |barbegin1 = green |barend1 = green |2={{cladex |label1=[[Capitosauridae]] |1={{cladex |1={{cladex |1=''[[Samarabatrachus]]'' |2={{cladex |1=''[[Poryolosuchus]]'' |2=''[[Parotosuchus]]'' }} }} |2={{cladex |1=''[[Selenocara]]'' |2={{cladex |1=''[[Wetlugasaurus]]'' |2=''[[Vladlenosaurus]]'' }} }} }} |2= {{Barlabel|size=13|at=1|label=[[Qantasidae]]|colour=violet|style=font-size:100% |cladogram= {{clade |1=''[[Qantas (genus)|Qantas]]'' |barbegin1 = violet |barend1 = violet |2={{clade |label1=[[Trematosauridae]] |1={{clade |1=''[[Prothoosuchus]]'' |2={{clade |1=''[[Thoosuchus]]'' |2={{clade |1=''[[Trematotegmen]]'' |2={{clade |1=''[[Angusaurus]]'' |2={{clade |1=''[[Inflectosaurus]]'' |2=''[[Trematosaurus]]'' }} }} }} }} }} |2= {{Barlabel|size=4|at=1|label=[[Benthosuchidae]]|colour=blue|style=font-size:100% |cladogram= {{cladex |1=''[[Syrtosuchus]]'' |barbegin1 = blue |2={{cladex |1='''''Benthosuchus''''' |barend1 = blue |2={{cladex |label1=[[Yarengiidae]] |1={{cladex |1=''[[Vyborosaurus]]'' |2=''[[Yarengia]]'' }} }} }} }} }} }} }} }} }} }} }} }}

==References== {{Reflist}}

[[Category:Trematosauria]] [[Category:Triassic temnospondyls]] [[Category:Extinct animals of Russia]] [[Category:Fossil taxa described in 1937]] [[Category:Taxa named by Ivan Yefremov]] [[Category:Triassic Russia]]