Captorhinidae

{{Short description|Extinct family of tetrapods}} {{Automatic taxobox | name = Captorhinids | fossil_range = Pennsylvanian - Lopingian {{Fossilrange|300|252}} | image = Captorhinus aguti p.jpg | image_caption = Fossil ''Captorhinus'' specimens | taxon = Captorhinidae | authority = Case, 1911 | type_species = {{extinct}}''Captorhinus aguti'' | type_species_authority = Cope, 1895 | subdivision_ranks = Genera | subdivision = See text | synonyms = '''Romeriidae''' <small>Price, 1937</small> }}

'''Captorhinidae''' is an extinct family of tetrapods, traditionally considered primitive reptiles, known from the late Carboniferous to the Late Permian. They had a cosmopolitan distribution across Pangea. They ecologically ranged from small carnivores to large herbivores.

==Description== [[File:Captorhinus kierani.jpg|left|thumb|Skull of ''Captorhinus kierani'']]

Captorhinids are a clade of small to very large lizard-like animals that date from the Late Carboniferous through the Permian. Their skulls were much stronger than those of their relatives, the protorothyridids, and had teeth that were better able to deal with tough plant material. The postcranial skeleton is similar to those of seymouriamorphs and diadectomorphs; these animals were grouped together with the captorhinids in the order Cotylosauria as the first reptiles in the early 20th century,<ref name="goodrich1916">{{cite journal|last=Goodrich|first=E.S.|title=On the classification of the Reptilia|journal=Proceedings of the Royal Society of London|volume= 89B|issue=615|pages=261–276|year=1916|doi=10.1098/rspb.1916.0012|bibcode=1916RSPSB..89..261G|doi-access=}}</ref> but are now usually regarded as stem-amniotes no closer to reptiles than to mammals. Captorhinids have broad, robust skulls that are generally triangular in shape when seen in dorsal view. The premaxillae are characteristically downturned. The largest captorhinid, the herbivorous ''Moradisaurus'', could reach an estimated snout-vent length (head and body length) of 2 meters (6.5 feet).<ref>[https://ejournals.library.ualberta.ca/index.php/VAMP/article/download/24960/18848 Multiple tooth-rowed captorhinids from the early Permian fissure fills of the Bally Mountain Locality of Oklahoma]</ref> Early, smaller forms possessed single rows of teeth, and were likely carnivorous or omnivorous, while the larger, more derived captorhinids belonging to the subfamily Moradisaurinae were herbivorous and developed multiple (up to 11) rows of teeth in the jaws alongside propalinal (back and forth) jaw motion, which created an effective apparatus for grinding and shredding plant matter.<ref>{{Cite journal|last=Brocklehurst|first=Neil|date=2017-04-13|title=Rates of morphological evolution in Captorhinidae: an adaptive radiation of Permian herbivores|journal=PeerJ|language=en|volume=5|article-number=e3200|doi=10.7717/peerj.3200|pmid=28417061|issn=2167-8359|pmc=5392250 |doi-access=free }}</ref>

Histological and SEM analysis of captorhinid tail vertebrae concluded in a 2018 study that captorhinids were the first amniotes to develop caudal autotomy as a defensive function. In studied specimens a split line is present in certain caudal vertebrae that is similar to those found in modern reptiles that perform caudal autonomy. This behaviour represented significant evolutionary benefit for the animals, allowing for escape and distracting predators, as well as minimizing blood loss at an injury site.<ref>{{Cite journal|last1=LeBlanc|first1=A. R. H.|last2=MacDougall|first2=M. J.|last3=Haridy|first3=Y.|last4=Scott|first4=D.|last5=Reisz|first5=R. R.|date=2018-03-05|title=Caudal autotomy as anti-predatory behaviour in Palaeozoic reptiles|journal=Scientific Reports|language=En|volume=8|issue=1|page=3328|doi=10.1038/s41598-018-21526-3|issn=2045-2322|pmc=5838224|pmid=29507301|bibcode=2018NatSR...8.3328L}}</ref>

Mummified specimens of ''Captorhinus'' indicate that captorhinids were covered in epidermal scales, similar to modern reptiles, and they had a cartilaginous sternum and cartilaginous extensions of the cervical ribs and trunk ribs, suggesting that they used the intercostal muscles to breathe similarly to modern lizards as opposed to the buccal breathing utilized by amphibians.<ref>{{Cite journal |last=Reisz |first=Robert R. |last2=Mooney |first2=Ethan D. |last3=Maho |first3=Tea |last4=Mazierski |first4=David |last5=Chu |first5=Xu |last6=Bevitt |first6=Joseph J. |last7=Lee |first7=Yao-Chang |last8=Huang |first8=Pei-Yu |last9=Li |first9=Xiaobo |last10=Chen |first10=Jun |date=2026-04-08 |title=Mummified early Permian reptile reveals ancient amniote breathing apparatus |url=https://www.nature.com/articles/s41586-026-10307-y |journal=Nature |language=en |doi=10.1038/s41586-026-10307-y |issn=0028-0836|url-access=subscription }}</ref>[[File:Labidos1.jpg|thumb|left|An impression of ''Labidosaurikos'']]

==Classification==

===Taxonomy=== The following taxonomy follows Reisz et al., 2011 and Sumida et al., 2010 unless otherwise noted.<ref name="Gansurhinus">{{Cite journal |author1=Robert R. Reisz |author2=Jun Liu |author3=Jin-Ling Li |author4=Johannes Müller |year=2011 |title=A new captorhinid reptile, ''Gansurhinus qingtoushanensis'', gen. et sp. nov., from the Permian of China |journal=Naturwissenschaften |volume=98 |issue=5 |pages=435–441 |bibcode=2011NW.....98..435R |doi=10.1007/s00114-011-0793-0 |pmid=21484260 |s2cid=20274349}}</ref><ref name=Sumida2010>{{cite journal |last=Sumida |first=S.S. |author2=Dodick, J. |author3=Metcalf, A. |author4=Albright, G. |year=2010 |title=''Reiszorhinus olsoni'', a new single-tooth-rowed captorhinid reptile of the Lower Permian of Texas |journal=Journal of Vertebrate Paleontology |volume=30 |issue=3 |pages=704–714 |doi=10.1080/02724631003758078|bibcode=2010JVPal..30..704S |s2cid=31500853 }}</ref>

*Family '''Captorhinidae''' ** ''Captorhinoides''? ** ''Acrodenta''<ref name=Acrodentanew>{{cite journal|author1=Nor-Eddine Jalil |author2=Jean-Michel Dutuit |year=1996 |title=Permian captorhinid reptiles from the Argana formation, Morocco |url=http://palaeontology.palass-pubs.org/pdf/Vol%2039/Pages%20907-918.pdf |journal=Palaeontology |volume=39 |issue=4 |pages=907–918 |url-status=usurped |archive-url=https://web.archive.org/web/20120425051119/http://palaeontology.palass-pubs.org/pdf/Vol%2039/Pages%20907-918.pdf |archive-date=2012-04-25 }}</ref> ** ''Baeotherates''<ref name=Baeotherates>{{cite journal |author=W. J. May |author2=Richard L. Cifelli |name-list-style=amp |year=1998 |title=''Baeotherates fortsillensis'', A New Captorhinid Reptile from the Fort Sill Fissures, Lower Permian of Oklahoma |journal=Oklahoma Geology Notes |volume=58 |pages=128–137 }}</ref> ** ''Captorhinus'' ** ''Euconcordia'' ** ''Labidosauriscus'' ** ''Opisthodontosaurus'' ** ''Protocaptorhinus'' ** ''Reiszorhinus'' ** ''Rhiodenticulatus'' ** ''Romeria'' ** ''Saurorictus'' ** Subfamily '''Moradisaurinae''' *** ''Amenoyengi''<ref name="Amenoyengi">{{Cite journal |last1=Jenkins |first1=Xavier A. |last2=Browning |first2=Claire |last3=Choiniere |first3=Jonah |last4=Peecook |first4=Brandon R. |date=2025-08-07 |title=A new moradisaurine captorhinid from the Upper Permian (Lopingian) upper Madumabisa Mudstone Formation (Luangwa Basin) of Zambia |journal=Journal of Vertebrate Paleontology |language=en |volume=45 |issue=sup1 |doi=10.1080/02724634.2024.2427529 |issn=0272-4634}}</ref> *** ''Balearosaurus'' *** ''Captorhinikos'' *** ''Gansurhinus'' *** ''Gecatogomphius''<ref name="PBDB">[http://www.paleodatabase.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=134808 The Paleobiology Database: Moradisaurinae] {{webarchive|url=https://web.archive.org/web/20111004042054/http://www.paleodatabase.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=134808|date=2011-10-04}}</ref> *** ''Indosauriscus''<ref name="Reisz2024">{{cite journal |last1=Reisz |first1=R. R. |last2=Chatterjee |first2=S. |last3=Modesto |first3=S. P. |title=A new moradisaurine captorhinid reptile (Amniota: Eureptilia) from the upper Permian of India |journal=PeerJ |date=2024 |volume=12 |article-number=e18394 |doi=10.7717/peerj.18394|doi-access=free |pmc=11569782 }}</ref> *** ''Kahneria''<ref name = PBDB/> *** ''Labidosaurikos'' *** ''Labidosaurus'' *** ''Moradisaurus'' *** ''Rothianiscus'' *** ''Sumidadectes''<ref name="Jung2024">{{cite journal |last1=Jung |first1=J. P. |last2=Sues |first2=H.-D. |title=Reassessment of ''{{'}}Captorhinikos{{'}} chozaensis'', an early Permian (Cisuralian: Kungurian) captorhinid reptile from Oklahoma and north-central Texas |journal=Journal of Paleontology |date=2024 |volume=98 |issue=1 |pages=115–127 |doi=10.1017/jpa.2023.85|bibcode=2024JPal...98..115J }}</ref> *** ''Tramuntanasaurus''<ref>{{cite journal |last1=Matamales-Andreu |first1=R. |last2=Mujal |first2=E |last3=Galobart |first3=À |last4=Fortuny |first4=J |title=A new medium-sized moradisaurine captorhinid eureptile from the Permian of Mallorca (Balearic Islands, western Mediterranean) and correlation with the co-occurring ichnogenus ''Hyloidichnus'' |journal=Papers in Palaeontology |date=2023 |volume=9 |issue=3 |article-number=e1498 |doi=10.1002/spp2.1498 |bibcode=2023PPal....9E1498M |url=https://onlinelibrary.wiley.com/doi/abs/10.1002/spp2.1498}}</ref> * '''Dubious captorhinids''' ** ''Puercosaurus'' ** ''Riabininus'' ** ''Chamasaurus'' ''Euconcordia cunninghami'' is thought to be the basalmost known member of Captorhinidae. A phylogenic study of primitive reptile relationships by Muller & Reisz in 2006 recovered ''Thuringothyris'' as a sister taxon of the Captorhinidae.<ref name="muller&reisz2006">Muller, J. and Reisz, R.R. (2006). "The phylogeny of early eureptiles: Comparing parsimony and Bayesian approaches in the investigation of a basal fossil clade." ''Systematic Biology'', '''55'''(3):503-511. {{doi|10.1080/10635150600755396}}</ref> The same results were obtained in later phylogenic analyses.<ref name="Gansurhinus" /><ref name="Sumida2010" />

Captorhinidae contains a single subfamily, the '''Moradisaurinae'''. Moradisaurinae was named and assigned to the family Captorhinidae by A. D. Ricqlès and P. Taquet in 1982. Moradisaurinae was defined as "all captorhinids more closely related to ''Moradisaurus'' than to ''Captorhinus''". The moradisaurines inhabited what is now China, Morocco, Niger, Russia, Texas and Oklahoma.<ref name="Gansurhinus" />

Captorhinids were once thought to be the ancestors of turtles. The Middle Permian reptile ''Eunotosaurus'' from South Africa was seen as the "missing link" between cotylosaurs and chelonians throughout much of the early 20th century.<ref name="WDMS14">{{cite journal |last=Watson |first=D.M.S. |year=1914 |title=''Eunotosaurus africanus'' Seeley and the ancestors of the Chelonia |journal=Proceedings of the Zoological Society of London |volume=11 |pages=1011–1020}}</ref> However, more recent fossil finds have shown that ''Eunotosaurus'' was either a parareptile or a diapsid, and therefore unrelated to captorhinids.<ref name="AAR">{{cite web |title=Facts About Turtles: Eunotosaurus And Turtle Evolution |url=http://www.all-about-reptiles.com/facts-about-turtles.html |archive-url=https://web.archive.org/web/20100912082824/http://www.all-about-reptiles.com/facts-about-turtles.html |archive-date=12 September 2010 |access-date=1 August 2010 |work=All-About-Reptiles.com |df=dmy-all}}</ref><ref name="Schoch2015">{{cite journal |last1=Schoch |first1=R. R. |last2=Sues |first2=H.-D. |date=2015 |title=A Middle Triassic stem-turtle and the evolution of the turtle body plan |journal=Nature |volume=523 |issue=7562 |pages=584–587 |bibcode=2015Natur.523..584S |doi=10.1038/nature14472 |pmid=26106865}}</ref>

===Phylogeny=== The cladogram below follows the topology from a 2011 analysis by paleontologists Robert R. Reisz, Jun Liu, Jin-Ling Li and Johannes Müller.<ref name=Gansurhinus/>

{{clade| style=font-size:85%;line-height:85% |1={{clade |1=''Paleothyris'' |2={{clade |1=''Thuringothyris'' |label2='''Captorhinidae''' |2={{clade |1=''Concordia'' |2={{clade |1=''Rhiodenticulatus'' |2={{clade |1=''Romeria'' |2={{clade |1=''Protocaptorhinus'' |2={{clade |1=''Saurorictus'' |2={{clade |label1=''Captorhinus'' |1={{clade |1=''C. laticeps'' |2={{clade |1=''C. aguti'' |2=''C. magnus'' }} }} |2={{clade |1=''Captorhinikos'' |2={{clade |1=''Labidosaurus'' |label2='''Moradisaurinae''' |2={{clade |1=''Labidosaurikos'' |2={{clade |1=''Moradisaurus'' |2={{clade |1=''Rothianiscus'' |2=''Gansurhinus'' }} }} }} }} }} }} }} }} }} }} }} }} }} }}

Traditional classification of Captorhinidae within Eureptilia, after Muller and Reisz (2006):<ref name="muller&reisz2006" />{{clade|{{clade |1=†Parareptilia |label2=Eureptilia |2={{clade |1=†''Coelostegus'' |2={{clade |1={{clade |1=†''Thuringothyris'' |2=†Captorhinidae }} |2={{clade |1=†''Brouffia'' |label2= |2={{clade |1=†''Paleothyris'' |2={{clade |1=†''Hylonomus'' |2={{clade |1={{clade |1=†''Anthracodromeus'' |2=†''Cephalerpeton'' |3=†''Protorothyris'' }} |2=Diapsida }} }} }} }} }} }} }}|style=font-size:100%;line-height:85%|label1=Reptilia/Sauropsida}}

Simões et al. (2022) recovered captorhinids as stem-amniotes instead, as the sister group to ''Protorothyris archeri'', while the clade including captorhinids and ''P. archeri'' was recovered as the sister group to Araeoscelidia. A cladogram from that study is shown below.<ref name="Simões2022">{{Cite journal |last1=Simões |first1=T. R. |last2=Kammerer |first2=C. F. |last3=Caldwell |first3=M. W. |last4=Pierce |first4=S. E. |title=Successive climate crises in the deep past drove the early evolution and radiation of reptiles |year=2022 |journal=Science Advances |volume=8 |issue=33 |article-number=eabq1898 |doi=10.1126/sciadv.abq1898 |pmid=35984885 |pmc=9390993 |doi-access=free |bibcode=2022SciA....8.1898S }}</ref> {{clade|{{clade |1=Seymouriamorpha 100px |2={{clade |1=Diadectomorpha 100px |2={{clade |1={{clade |1=Araeoscelidia 100px |2={{clade |1=''Protorothyris'' 100px |2=Captorhinidae 100px }}}} |label2=Amniota |2={{clade |1=Synapsida 100px |label2=Sauropsida |2={{clade |1=Acleistorhinidae 100px |2={{clade |1=Millerettidae 100px |2={{clade |1=Mesosauria 100px |label2=Neoreptilia |2={{clade |1=Procolophonia 100px |2=Neodiapsida (including modern reptiles and birds) }}}}}}}}}}}}}}}}|label1=Reptiliomorpha}}

Using an updated version of this data matrix, Klembara et al. (2023) recovered comparable results.<ref name="Klembara2023">{{cite journal |last1=Klembara |first1=J. |last2=Ruta |first2=M. |last3=Anderson |first3=J. |last4=Mayer |first4=T. |last5=Hain |first5=M. |last6=Valaška |first6=D. |date=2023 |title=A review of ''Coelostegus prothales'' Carroll and Baird, 1972 from the Upper Carboniferous of the Czech Republic and the interrelationships of basal eureptiles |journal=PLOS ONE |volume=18 |issue=9 |article-number=e0291687 |bibcode=2023PLoSO..1891687K |doi=10.1371/journal.pone.0291687 |pmc=10513281 |pmid=37733816 |doi-access=free}}</ref>

In contrast, Kelsey M. Jenkins et al. (2025) found a clade containing Captorhinidae and Araeoscelidia as the most basal branch of Sauropsida, supporting the traditional classification of captorhinids as a reptiles, though more basal than traditionally assumed,<ref>{{Cite journal |last=Jenkins |first=Kelsey M |last2=Meyer |first2=Dalton L |last3=Bhullar |first3=Bhart-Anjan S |date=2025-12-13 |title=Phylogenetic paradigm shifts in early amniote evolution |url=https://academic.oup.com/sysbio/advance-article/doi/10.1093/sysbio/syaf087/8379424 |journal=Systematic Biology |language=en |doi=10.1093/sysbio/syaf087 |issn=1063-5157|url-access=subscription }}</ref> though Xavier A. Jenkins et al. (2025) instead found captorhinids to be considerably outside Amniota.<ref name=":2">{{cite journal |last1=Jenkins|first1=Xavier A|last2=Benson|first2=Roger BJ|last3=Ford|first3=David P|last4=Browning|first4=Claire|last5=Fernandez|first5=Vincent|last6=Dollman|first6=Kathleen|last7=Gomes|first7=Timothy|last8=Griffiths|first8=Elizabeth|last9=Choiniere|first9=Jonah N|last10=Peecook|first10=Brandon R|title=Evolutionary assembly of crown reptile anatomy clarified by late Paleozoic relatives of Neodiapsida|journal=Peer Community Journal|date=28 August 2025|volume=5|article-number=e89|doi=10.24072/pcjournal.620|eissn=2804-3871|s2cid=274305322|doi-access=free}}</ref>{{clade|{{clade |1=Temnospondyli 50px |label2=Reptiliomorpha |sublabel2=(Pan-Amniota) |2={{clade |1={{extinct}}''Seymouria'' sp. 50px |2={{clade |1={{extinct}}Recumbirostra 50px |2={{clade |1={{extinct}}''Hylonomus'' 50px |2={{clade |1={{extinct}}Captorhinidae 50px |2={{clade |1={{extinct}}Diadectomorpha 55px |2={{clade |1={{extinct}}Protorothyrididae 50px |label2=Amniota |2={{clade |1=Synapsida 45px |2=Sauropsida/Reptilia 50px }} }} }} }} }} }} }} }}|label1=Tetrapoda}}

==References== {{Reflist}}

{{Portal|Paleontology}} {{Reptiliomorpha|A.}} {{Sauropsida|E.}} {{Taxonbar|from=Q141936}}

Category:Captorhinidae Category:Prehistoric tetrapod families Category:Carboniferous tetrapods Category:Permian tetrapods Category:Pennsylvanian first appearances Category:Lopingian extinctions Category:Taxa named by Ermine Cowles Case