Parasuchus

{{Short description|Extinct genus of reptiles}} {{Automatic taxobox | fossil_range = [[Late Triassic]], {{fossil_range|222.5|212}}| | image = Parasuchus hislopi skull.png | image_upright = 1.15 | image_caption = The skull of ISI R42, the [[neotype]] of ''Parasuchus hislopi'' | taxon = Parasuchus | authority = [[Richard Lydekker|Lydekker]], [[1885 in paleontology|1885]] | type_species = {{extinct}}'''''Parasuchus hislopi''''' | type_species_authority = Lydekker, 1885 }}

'''''Parasuchus''''' is an [[extinct]] [[genus]] of [[Basal (phylogenetics)|basal]] [[phytosaur]] known from the [[Late Triassic]] (late [[Carnian]] to early [[Norian]] stage) of [[Telangana]] and [[Madhya Pradesh]], [[India]]. At its most restricted definition, ''Parasuchus'' contains a single species, '''''Parasuchus hislopi'''''.<ref name=Chatterjee78>{{cite journal |author=Sankar Chatterjee |year=1978 |title=A primitive parasuchid (phytosaur) reptile from the Upper Triassic Maleri Formation of India |url=http://palaeontology.palass-pubs.org/pdf/Vol%2021/Pages%2083-127.pdf |journal=Palaeontology |volume=21 |issue=1 |pages=83–127 |access-date=2012-05-12 |url-status=usurped |archive-url=https://web.archive.org/web/20130810232427/http://palaeontology.palass-pubs.org/pdf/Vol%2021/Pages%2083-127.pdf |archive-date=2013-08-10 }}</ref><ref name=Nesbitt11/> ''Parasuchus hislopi'' is one of several species belonging to a basal [[Evolutionary grade|grade]] of phytosaurs, typified by the genus ''[[Paleorhinus]]''. Historically, ''Paleorhinus'' has been known from better-described fossils, and many species have been [[Lumpers and splitters|lumped]] into that genus. ''Parasuchus hislopi'', despite being described earlier than ''Paleorhinus'', was considered an undiagnostic [[Chimera (paleontology)|chimera]] until new [[neotype]] fossils were described in the late 1970s. ''Parasuchus hislopi'' and the two unambiguously valid species of ''Paleorhinus'' (''P. bransoni'' and ''P. angustifrons'') are all closely related; some authors have historically described them all under the species ''Paleorhinus'', while others place the two ''Paleorhinus'' species into ''Parasuchus'' according to the [[principle of priority]].<ref name=":0" /> The bite force of ''Parasuchus hislopi'' is estimated to be 450 newtons at the anterior portion of the jaw, with 1,958 newtons at the posterior portion.<ref>{{cite journal | doi=10.7717/peerj.13731 | title=Estimating bite force in extinct dinosaurs using phylogenetically predicted physiological cross-sectional areas of jaw adductor muscles | year=2022 | last1=Sakamoto | first1=Manabu | journal=PeerJ | volume=10 | article-number=e13731 | pmid=35846881 | pmc=9285543 | doi-access=free }}</ref>

==History== The name ''Parasuchus'' was first used by [[Thomas Henry Huxley]] (1870) in a faunal list. Since a diagnosis wasn't provided, it would have been considered a ''[[nomen nudum]]'' at the time. [[Richard Lydekker]] (1885) formally described and named ''P. hislopi'', and proposed the family name [[Parasuchidae]]. However, Lydekker's description was based on a [[Chimera (paleontology)|chimeric]] [[syntype]], combining fossils from multiple unrelated reptiles: a [[rhynchosauria]]n [[basicranium]] mixed with the partial snout of a [[phytosauria|phytosaur]], scutes and some teeth. [[Friedrich von Huene]] (1940) identified the basicranium as belonging to ''[[Paradapedon huxleyi]]'' (now known as ''[[Hyperodapedon]] huxleyi'') and the phytosaurian material to a newly named species, "aff." ''[[Brachysuchus]] maleriensis''. Later, [[Edwin Harris Colbert]] (1958) designated all the Indian parasuchian material as ''[[Phytosaurus]] maleriensis'' while Gregory (1962) considered the material undiagnostic.

[[Sankar Chatterjee]] (1978) described many complete remains of the Indian parasuchian and showed that it is not assignable either to ''[[Brachysuchus]]'' (which is closely related to or synonymous with ''[[Angistorhinus]]''), or to ''[[Phytosaurus]]'' (a [[Nomen dubium|dubious name]], probably the [[senior synonym]] of ''[[Nicrosaurus]]''). He argued that the rhynchosaur basicranium qualifies as neither the [[holotype]] of ''P. hislopi'', nor the [[lectotype]] of ''Paradapedon huxleyi.'' He re-introduced ''P. hislopi'', based on Lydekker's snout fossil and new well-preserved material.<ref name="Chatterjee78" /> To avoid additional confusion, the nondiagnostic holotype of ''P. hislopi'' was replaced by a [[neotype]] (ISI R 42) with approval from the [[International Commission on Zoological Nomenclature|ICZN]] (Opinion 2045) following the application of Chatterjee (2001).<ref name="ICZN">{{cite journal |year=2003 |title=''Parasuchus Hislopi'' Lydekker, 1885 (Reptilia, Archosauria): Lectotype Replaced By A Neotype |url=http://biostor.org/cache/pdf/b8/fc/68/b8fc688a53ce7a142c5951d1ed169396.pdf |journal=Bulletin of Zoological Nomenclature |volume=60 |pages=174–175 |archive-date=2015-06-11 |access-date=2012-05-12 |archive-url=https://web.archive.org/web/20150611061903/http://biostor.org/cache/pdf/b8/fc/68/b8fc688a53ce7a142c5951d1ed169396.pdf |url-status=dead }}</ref>

=== Fossil material === The partial [[premaxillary]] [[Rostrum (anatomy)|rostrum]] (snout) originally described by Lydekker, [[Indian Museum Collection, Calcutta|GSI]] H 20/11, was chosen as the [[lectotype]] of ''Parasuchus hislopi'' by Sankar Chatterjee. GSI H 20/11 was collected from the [[Lower Maleri Formation]] ([[Pranhita–Godavari Basin]]), near the [[Maleri village]] of [[Adilabad district]], Telangana. The lectotype was rendered obsolete when neotype fossils were approved for the genus in 2003.<ref name="ICZN" /> [[File:Parasuchus hislopi skull side view.png|left|thumb|The [[neotype]] skull of ''Parasuchus hislopi'' (ISI R42)]] Sankar Chatterjee later described more comprehensive remains from the Lower Maleri Formation, as well as one nearly complete [[skull]] form the [[Tiki Formation]] that he also assigned to ''Parasuchus hislopi''. Two complete and articulated [[skeleton]]s that include complete skulls were collected from the Lower Maleri Formation in the vicinity of the [[Mutapyram village]] of Adilabad district. Both individuals were roughly {{convert|8|ft|m|abbr=on}} in length, lying side by side. The left individual, [[Geology Museum, Indian Statistical Institute|ISI]] R 42, is perfectly preserved, and was designated as the [[neotype]] of the species.<ref name="ICZN" /> The right individual, ISI R 43, is nearly complete and only missing part of the snout.<ref name="Chatterjee78" /><ref name=":0" />

Two [[Joint|articulated]] and almost complete [[skeleton]]s of ''[[Malerisaurus robinsonae]]'' (both designated as ISIR 150), an [[Azendohsauridae|azendohsaurid]] [[archosauromorph]], were found as presumable gastric contents of these two skeletons.<ref name="Malerisaurus">{{cite journal |author=Sankar Chatterjee |year=1980 |title=''Malerisaurus'', A New Eosuchian Reptile from the Late Triassic of India |journal=Philosophical Transactions of the Royal Society of London, Series B |volume=291 |issue=1048 |pages=163–200 |doi=10.1098/rstb.1980.0131|bibcode=1980RSPTB.291..163C |doi-access=free }}</ref> From the same locality as the neotype, three isolated conjoined basioccipital/basisphenoids (ISI R 45-47) were also recovered. A couple of miles north of that locality, near the [[Venkatapur village]], two more excellently preserved skulls were found. ISI R 160 represents an isolated but nearly complete skull, while ISI R 161 represents partial skull and articulated postcranial remains.<ref name="Chatterjee78" /> Finally, a skull recovered from the ''[[Tikisuchus]]'' holotype site of the Tiki Formation ([[Gondwana Group]]),<ref name="Tikisuchus">{{cite journal |author1=S. Chatterjee |author2=P. K. Majumdar |year=1987 |title=''Tikisuchus romeri'', a new rauisuchid reptile from the Late Triassic of India |journal=Journal of Paleontology |volume=61 |issue=4 |pages=787–793 |doi=10.1017/S0022336000029139 |s2cid=130472911 }}</ref> about 4 miles west of [[Tiki village]] of [[Shadol District]], Madhya Pradesh, is missing only the end of the snout and the [[squamosal]]. As the lectotype of the genus, it was found nearby ''[[Paradapedon]]'' remains.<ref name="Chatterjee78" /> Both formations date to the late [[Carnian]] to early [[Norian]] stage of the [[Late Triassic]] [[geological timescale|period]], about 222.5-212 [[million years ago]].<ref name="Tikisuchus" /><ref name="biostrati98">{{cite journal |author=Lucas, S. G. |year=1998 |title=Global Triassic tetrapod biostratigraphy and biochronology |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=143 |issue=4 |pages=347–384 |doi=10.1016/s0031-0182(98)00117-5|bibcode=1998PPP...143..347L |citeseerx=10.1.1.572.872 }}</ref>

== Classification == [[File:Paleorhinus.jpg|left|thumb|244x244px|''[[Paleorhinus]] cf. arenaceus'', a [[Poland|Polish]] phytosaur species tentatively referred to the genus ''Paleorhinus''. ''[[Paleorhinus]]'' is sometimes considered a [[junior synonym]] of ''Parasuchus,'' due to being described later]]The two articulated skeletons, ISI R 42-43, alone represent the most complete phytosaurs known to date. Additionally, ''Parasuchus'' has been found as one of the most primitive phytosaurs in phylogenetic analyses of Phytosauria, making it very significant for understanding the origin of the Phytosauria.<ref name="Nesbitt11">{{cite journal|author=Sterling J. Nesbitt |year=2011|title=The Early Evolution of Archosaurs: Relationships and the Origin of Major Clades|url=https://digitallibrary.amnh.org/handle/2246/6112|journal=Bulletin of the American Museum of Natural History|volume=352|pages=1–292|doi=10.1206/352.1|hdl=2246/6112|s2cid=83493714|doi-access=free}}</ref> Some studies, like Chatterjee (1978) and Lucas ''et al.'' (2007), synonymized ''Parasuchus'' with another [[basal (phylogenetics)|basal]] phytosaur, ''[[Paleorhinus]]''. If this is the case, the name ''Parasuchus'' would have precedence over ''Paleorhinus'' because ''Paleorhinus'' was named in 1904, nineteen years after ''Parasuchus'' was named. A phylogenetic analysis conducted by Kammerer ''et al.'' (2016) confirmed that ''Parasuchus hislopi'' is nested within the least inclusive clade containing the species ''Paleorhinus bransoni'' and ''Paleorhinus angustifrons''. The authors thus considered the genus ''Parasuchus'' to be a senior synonym of the genus ''Paleorhinus'' (as well as ''[[Arganarhinus]]''), and referred the species ''Paleorhinus bransoni'', ''Paleorhinus angustifrons'' and ''Arganarhinus magnoculus'' to the genus ''Parasuchus''.<ref name=":0">{{Cite journal|author1=Christian F. Kammerer |author2=Richard J. Butler |author3=Saswati Bandyopadhyay |author4=Michelle R. Stocker |year=2016 |title=Relationships of the Indian phytosaur ''Parasuchus hislopi'' Lydekker, 1885 |journal=Papers in Palaeontology |volume=2 |issue=1 |pages=1–23 |doi=10.1002/spp2.1022 |s2cid=83780331 |url=http://pure-oai.bham.ac.uk/ws/files/19880739/Kammerer_et_al._2015._Accepted_MS.pdf }}</ref> The [[cladogram]] below follows Kammerer ''et al.'' (2016).<ref name=":0" />

{{clade| style=font-size:100%;line-height:85% |label1=[[Parasuchidae]] |1={{clade |1=''[[Wannia scurriensis]]'' |2={{clade |1={{clade |1=''[[Parasuchus bransoni|Parasuchus (Paleorhinus) bransoni]]'' |2={{clade |1=''[[Parasuchus angustifrons|Parasuchus (Paleorhinus) angustifrons]]'' |2='''''Parasuchus hislopi''''' }} }} |2={{clade |1=''[[Ebrachosuchus neukami]]'' |label2=[[Mystriosuchinae]] |2={{clade |1=''[[Angistorhinus]]'' |2=''"Paleorhinus" sawini'' |3=''[[Brachysuchus megalodon]]'' |4={{clade |1=''[[Protome batalaria]]'' |2=''"Machaeroprosopus" zunii'' |3=''[[Rutiodon carolinensis]]'' |label4=[[Leptosuchomorpha]] |4={{clade |1=TMM 31173-120 |2=''"Phytosaurus" doughtyi'' |DUP-3={{clade |1=''[[Leptosuchus studeri]]'' |2={{clade |1=''[[Leptosuchus imperfecta]]'' |2=''[[Leptosuchus crosbiensis]]'' }} }} |3={{clade |1={{clade |1=''[[Smilosuchus lithodendrorum]]'' |2={{clade |1=''[[Smilosuchus gregorii]]'' |2=''[[Smilosuchus adamanensis]]'' }} }} |2={{clade |1=''[[Pravusuchus hortus]]'' |label2=[[Mystriosuchini]] |2={{clade |1=''[[Machaeroprosopus mccauleyi]]'' |2={{clade |1=''[[Machaeroprosopus pristinus]]'' |2={{clade |1=''[[Machaeroprosopus jablonskiae]]'' |2=''[[Mystriosuchus westphali]]''}} }} }} }} }} }} }} }} }} }} }} }}

==Etymology== ''Parasuchus'' was first described and named by [[Richard Lydekker]] in [[1885 in paleontology|1885]] and the [[type species]] is ''Parasuchus hislopi''. The [[name of a biological genus|generic name]] is derived from the [[Ancient Greek|Greek]] ''para''/παρα meaning "beside" or "near" and ''suchus'' from the Greek ''souchos'', which refers to the Egyptian crocodile-headed god [[Sobek]]. The [[specific name (zoology)|specific name]], ''hislopi'', honors Hislop who drawn attention in 1854 to the red clays near [[Maleri village]] in which the holotype (and later the neotype and other specimens) of ''P. hislopi'' was recovered.<ref name=oriParasuchus>{{cite journal |author=Richard Lydekker |year=1885 |title=Maleri and Denwa Reptilia and Amphibia |journal=Palaeontology Indica |volume=1 |pages=1–38 }}</ref>

==References== {{Reflist}} {{Portal|Paleontology}}

[[Category:Phytosauria]] [[Category:Prehistoric reptile genera]] [[Category:Late Triassic reptiles of Asia]] [[Category:Triassic India]] [[Category:Fossils of India]] [[Category:Taxa named by Richard Lydekker]] [[Category:Fossil taxa described in 1885]]