Clevosaurus (meaning "Gloucester lizard") is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassicperiods. Species of Clevosaurus were widespread across Pangaea, and have been found on all continents except Australia and Antarctica.[1] Five species of Clevosaurus have been found in ancient fissure fill deposits in south-west England and Wales, alongside other sphenodontians, early mammals and dinosaurs. In regards to its Pangaean distribution, C. hadroprodon is the oldest record of a sphenodontian from Gondwana,[2] though its affinity to Clevosaurus has been questioned.[3]
Another notable specimen was discovered in 1953 in Cromhall Quarry alongside the holotype of Cryptovaranoides microlanius.[5]
Descriptionedit
Skull of Clevosaurus brasiliensis
Species of Clevosaurus varied in body size, with Clevosaurus sectumsemper having an estimated total length of 12 centimetres (4.7 in), while C. hudsoni had a total length of around 25 centimetres (9.8 in). The skull length could range from as little as 1.4 centimetres (0.55 in) in C. sectumsemper and up to 4 centimetres (1.6 in) in C. hudsoni.[6] Notable for their greatly reduced number of teeth (3-6 per jaw quadrant), broad skulls and shortened snouts. The teeth of european clevosaurs tended to be mesio-distally elongated, blade-like, and occluded precisely with the opposite pair of teeth, leaving conspicuous diagonal wear facets and acting as a self-sharpening cutting surface.[7] However, the teeth of C. brasiliensis have a very different morphology with no diagonal wear facets, the teeth of the dentary are all conical excluding the posterior-most tooth which can be up to three-times bigger than any of the other teeth, they also have a unique form of implantation, where the base of the teeth sit deeply within the jaw bones, which is not known of in any other rhynchocephalian.[3]
Paleobiologyedit
Life restoration of Clevosaurus hadroprodon
Species of Clevosaurus were likely insectivorous. Biomechanical modelling suggests that they had high enough tooth pressures and strong enough bite force to crush chitin, indicating that they had the ability to feed on thick-shelled beetles as well as possibly small vertebrates.[7]
Taxonomyedit
At least 9 species of Clevosaurus are considered valid:
†Clevosaurus minor Fraser 1988 Cromhall Quarry fissure fill, England, Rhaetian
†Clevosaurus sectumsemper Klein et al. 2015[11] Woodleaze Quarry fissure fill, England, Rhaetian
†Clevosaurus nicholasi Bhat et al. 2023[12]Tiki Formation, India, late Carnian-middle Norian
The three species known from the Sinemurian aged Lufeng Formation of China (C. mcgilli, C.wangi and C. petilus) are now considered indeterminate within the genus.[13] Indeterminate remains are also known from the Stormberg Group (either Elliot or Clarens Formation) of South Africa, dating to the Hettangian.[1]
Clevosaurus is considered to be a member of the group Eusphenodontia by the groups definition, due to it possessing characters not shared with more primitive sphenodontians. By definition, it is excluded from Neosphenodontia.[15]
Position of Clevosaurus within Rhynchocephalia, after DeMar et al. 2022.[16]
^ abSues, H. D.; Reisz, R. (1995). "First record of the early mesozoic sphenodontian clevosaurus (lepidosauria: rhynchocephalia) from the southern hemisphere". Journal of Paleontology. 69 (1): 123–126. Bibcode:1995JPal...69..123S. doi:10.1017/s0022336000026974. S2CID 131414921.
^"A new sphenodontian from Brazil is the oldest record of the group in Gondwana". phys.org. Retrieved 2019-08-15.
^ abChambi-Trowell, Sofia A. V.; Martinelli, Agustín G.; Whiteside, David I.; Vivar, Paulo R. Romo de; Soares, Marina Bento; Schultz, Cesar L.; Gill, Pamela G.; Benton, Michael J.; Rayfield, Emily J. (2021-06-03). "The diversity of Triassic South American sphenodontians: a new basal form, clevosaurs, and a revision of rhynchocephalian phylogeny". Journal of Systematic Palaeontology. 19 (11): 787–820. Bibcode:2021JSPal..19..787C. doi:10.1080/14772019.2021.1976292. hdl:1983/af14affc-a26e-426b-83ca-e1833e355882. ISSN 1477-2019. S2CID 240487298.
^W. E. Swinton. (1939). A new Triassic rhynchocephalian from Gloucestershire. Annals and Magazine of Natural History: Zoology, Botany, and Geology4:591-594
^Whiteside, D. I.; Chambi-Trowell, S. A. V.; Benton, M. J. (2022). "A Triassic crown squamate". Science Advances. 8 (48): eabq8274. Bibcode:2022SciA....8.8274W. doi:10.1126/sciadv.abq8274. hdl:1983/a3c7a019-cfe6-4eb3-9ac0-d50c61c5319e. ISSN 2375-2548. PMID 36459546.
^ abKeeble, Emily; Whiteside, David I.; Benton, Michael J. (April 2018). "The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures, South Wales, UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)". Proceedings of the Geologists' Association. 129 (2): 99–119. Bibcode:2018PrGA..129...99K. doi:10.1016/j.pgeola.2017.11.001. hdl:1983/5afdc677-3ea0-4519-813d-6052ef8370ec.
^ abChambi-Trowell, Sofia A. V.; Whiteside, David I.; Benton, Michael J.; Rayfield, Emily J. (16 June 2020). Lautenschlager, Stephan (ed.). "Biomechanical properties of the jaws of two species of Clevosaurus and a reanalysis of rhynchocephalian dentary morphospace". Palaeontology. 63 (6): 919–939. Bibcode:2020Palgy..63..919C. doi:10.1111/pala.12493. ISSN 0031-0239. S2CID 220902843.
^Bonaparte, J. F.; Sues, H. D. (2006). "A new species of clevosaurus (lepidosauria: rhynchocephalia) from the upper Triassic of Rio Grande do Sul, Brazil". Palaeontology. 49 (1): 917–923. Bibcode:2006Palgy..49..917B. doi:10.1111/j.1475-4983.2006.00568.x. S2CID 26483165.
^Säilä, Laura K. (2005). "A new species of the sphenodontian reptile Clevosaurus from the Lower Jurassic of South Wales". Palaeontology. 48 (4): 817–831. Bibcode:2005Palgy..48..817S. doi:10.1111/j.1475-4983.2005.00486.x.
^Hsiou, Annie S.; Nydam, Randall L.; Simões, Tiago R.; Pretto, Flávio A.; Onary, Silvio; Martinelli, Agustín G.; Liparini, Alexandre; Martínez, Paulo R. Romo de Vivar; Soares, Marina B.; Schultz, Cesar L.; Caldwell, Michael W. (2019-08-14). "A New Clevosaurid from the Triassic (Carnian) of Brazil and the Rise of Sphenodontians in Gondwana". Scientific Reports. 9 (1): 11821. Bibcode:2019NatSR...911821H. doi:10.1038/s41598-019-48297-9. ISSN 2045-2322. PMC6694142. PMID 31413294.
^Klein, Catherine G.; Whiteside, David I.; de Lucas, Victor Selles; Viegas, Pedro A.; Benton, Michael J. (2015). "A distinctive Late Triassic microvertebrate fissure fauna and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia) from Woodleaze Quarry, Gloucestershire, UK". Proceedings of the Geologists' Association. 126 (3): 402–416. Bibcode:2015PrGA..126..402K. doi:10.1016/j.pgeola.2015.05.003.
^Bhat, Mohd Shafi; Datta, Debajit; Ray, Sanghamitra; Datta, P. M. (2023-01-02). "A new clevosaurid (Lepidosauria: Rhynchocephalia) from the Upper Triassic of IndiaCitation for this article: Bhat, M. S., Datta, D., Ray, S., & Datta, P. M. (2023) A new clevosaurid (Lepidosauria: Rhynchocephalia) from the Upper Triassic of India. Journal of Vertebrate Paleontology". Journal of Vertebrate Paleontology. 43 (1). Bibcode:2023JVPal..43E2833B. doi:10.1080/02724634.2023.2232833. ISSN 0272-4634. S2CID 260525273.
^Jones MEH. 2006 The Early Jurassic clevosaurs from China (Diapsida: Lepidosauria). New Mex. Museum Nat. Hist. Sci. Bull. 37, 548–562.
^ abAnnie Schmaltz Hsiou; Marco Aurélio Gallo De França; Jorge Ferigolo (2015). "New Data on the Clevosaurus (Sphenodontia: Clevosauridae) from the Upper Triassic of Southern Brazil". PLOS ONE. 10 (9): e0137523. Bibcode:2015PLoSO..1037523H. doi:10.1371/journal.pone.0137523. PMC4565693. PMID 26355294.
^ abJorge A. Herrera-Flores; Thomas L. Stubbs; Armin Elsler; Michael J. Benton (2018). "Taxonomic reassessment of Clevosaurus latidens Fraser, 1993 (Lepidosauria, Rhynchocephalia) and rhynchocephalian phylogeny based on parsimony and Bayesian inference". Journal of Paleontology. 92 (4): 734–742. Bibcode:2018JPal...92..734H. doi:10.1017/jpa.2017.136. hdl:1983/59126b60-16d8-46d2-b657-954693a39d4e.
^DeMar, David G.; Jones, Marc E. H.; Carrano, Matthew T. (2022-12-31). "A nearly complete skeleton of a new eusphenodontian from the Upper Jurassic Morrison Formation, Wyoming, USA, provides insight into the evolution and diversity of Rhynchocephalia (Reptilia: Lepidosauria)". Journal of Systematic Palaeontology. 20 (1): 1–64. doi:10.1080/14772019.2022.2093139. hdl:2440/136608. ISSN 1477-2019. S2CID 252325953.
Additional readingedit
Gill PG, Säilä LK, Corfe IJ, Challands TJ, Williams M, Clemens WA (2006). The fauna and palaeoenvironment of St. Brides Island: Evidence from the lower Jurassic fissure fills of South Wales. In Barrett PM, Evans SE (eds.). Ninth international symposium on Mesozoic terrestrial ecosystems and biota. pp 48−51. London: Natural History Museum.
Jones MEH (2006) The Early Jurassic clevosaurs from China (Diapsida: Lepidosauria). Natl Mus Nat Hist Sci Bull, 37:548–562.
Jones MEH (2009). Dentary tooth shape in Sphenodon and its fossil relatives (Diapsida: Lepidosauria: Rhynchocephalia). In Koppe T, Meyer G, Alt KW, (eds). Interdisciplinary Dental Morphology, Frontiers of Oral Biology (vol 13). Greifswald, Germany; Karger. 9–15.
clevosaurus, meaning, gloucester, lizard, extinct, genus, rhynchocephalian, reptile, from, late, triassic, early, jurassic, periods, species, were, widespread, across, pangaea, have, been, found, continents, except, australia, antarctica, five, species, have, . Clevosaurus meaning Gloucester lizard is an extinct genus of rhynchocephalian reptile from the Late Triassic and the Early Jurassic periods Species of Clevosaurus were widespread across Pangaea and have been found on all continents except Australia and Antarctica 1 Five species of Clevosaurus have been found in ancient fissure fill deposits in south west England and Wales alongside other sphenodontians early mammals and dinosaurs In regards to its Pangaean distribution C hadroprodon is the oldest record of a sphenodontian from Gondwana 2 though its affinity to Clevosaurus has been questioned 3 ClevosaurusTemporal range Late Triassic Early Jurassic Carnian Sinemurian PreꞒ Ꞓ O S D C P T J K Pg N Skulls of Clevosaurus hudsoni left and C cambrica right Scientific classification Domain Eukaryota Kingdom Animalia Phylum Chordata Class Reptilia Order Rhynchocephalia Family Clevosauridae Genus ClevosaurusSwinton 1939 Species See text Synonyms Dianosaurus Young 1982 Reconstructions of the skulls of C hudsoni A and C cambrica B reconstructed areas in orange Contents 1 History of discovery 2 Description 3 Paleobiology 4 Taxonomy 5 References 6 Additional readingHistory of discovery editThe first species of Clevosaurus to be described was C hudsoni which was described by William Elgin Swinton in 1939 from a fissure fill deposit in Cromhall Quarry Magnesian Conglomerate Formation in the county of Gloucestershire England with the name of the county lending its name to the genus 4 Another notable specimen was discovered in 1953 in Cromhall Quarry alongside the holotype of Cryptovaranoides microlanius 5 Description edit nbsp Skull of Clevosaurus brasiliensis Species of Clevosaurus varied in body size with Clevosaurus sectumsemper having an estimated total length of 12 centimetres 4 7 in while C hudsoni had a total length of around 25 centimetres 9 8 in The skull length could range from as little as 1 4 centimetres 0 55 in in C sectumsemper and up to 4 centimetres 1 6 in in C hudsoni 6 Notable for their greatly reduced number of teeth 3 6 per jaw quadrant broad skulls and shortened snouts The teeth of european clevosaurs tended to be mesio distally elongated blade like and occluded precisely with the opposite pair of teeth leaving conspicuous diagonal wear facets and acting as a self sharpening cutting surface 7 However the teeth of C brasiliensis have a very different morphology with no diagonal wear facets the teeth of the dentary are all conical excluding the posterior most tooth which can be up to three times bigger than any of the other teeth they also have a unique form of implantation where the base of the teeth sit deeply within the jaw bones which is not known of in any other rhynchocephalian 3 Paleobiology edit nbsp Life restoration of Clevosaurus hadroprodonSpecies of Clevosaurus were likely insectivorous Biomechanical modelling suggests that they had high enough tooth pressures and strong enough bite force to crush chitin indicating that they had the ability to feed on thick shelled beetles as well as possibly small vertebrates 7 Taxonomy editAt least 9 species of Clevosaurus are considered valid Clevosaurus bairdi Sues et al 1994 McCoy Brook Formation Canada Hettangian Clevosaurus brasiliensis Bonaparte and Sues 2006 8 Caturrita Formation Brazil Norian Clevosaurus cambrica Keeble et al 2018 6 Pant y ffynnon Quarry fissure fill Wales Rhaetian Clevosaurus convallis Saila 2005 9 St Bride s Island fissure fill Wales Hettangian Clevosaurus hadroprodon Hsiou et al 2019 10 Santa Maria Formation Brazil Carnian Clevosaurus hudsoni Swinton 1939 Cromhall Quarry fissure fill England Rhaetian Clevosaurus minor Fraser 1988 Cromhall Quarry fissure fill England Rhaetian Clevosaurus sectumsemper Klein et al 2015 11 Woodleaze Quarry fissure fill England Rhaetian Clevosaurus nicholasi Bhat et al 2023 12 Tiki Formation India late Carnian middle Norian The three species known from the Sinemurian aged Lufeng Formation of China C mcgilli C wangi and C petilus are now considered indeterminate within the genus 13 Indeterminate remains are also known from the Stormberg Group either Elliot or Clarens Formation of South Africa dating to the Hettangian 1 Below is a cladogram of the relationships within Clevosauridae based on the phylogenetic analysis of Hsiou et al 2015 14 Clevosauridae Polysphenodon mulleri Brachyrhinodon taylori Clevosaurus sp South Africa Clevosaurus convallis Clevosaurus hudsoni Clevosaurus petilus Clevosaurus bairdi Clevosaurus mcgilli Clevosaurus wangi Clevosaurus brasiliensis Clevosaurus cambrica Clevosaurus latidens was recovered outside of Clevosauridae as the sister taxon of Opisthodontia 14 It was subsequently assigned to a new genus Fraserosphenodon in 2018 15 Clevosaurus is considered to be a member of the group Eusphenodontia by the groups definition due to it possessing characters not shared with more primitive sphenodontians By definition it is excluded from Neosphenodontia 15 Position of Clevosaurus within Rhynchocephalia after DeMar et al 2022 16 Younginia capensis Prolacerta broomi Lepidosauria Pan Squamata Sophineta cracoviensis Pristidactylus Eichstaettisaurus schroederi Megachirella wachtleri Marmoretta oxoniensis Rhynchocephalia Gephyrosaurus bridensis Sphenodontia Diphydontosaurus avonis Acrosphenodontia Planocephalosaurus robinsonae Rebbanasaurus jaini Godavarisaurus lateefi Theretairus antiquus Eusphenodontia Polysphenodon mulleri Opisthiamimus gregori Clevosaurus Clevosaurus convallis Clevosaurus brasiliensis Clevosaurus hadroprodon Clevosaurus bairdi Clevosaurus hudsoni Clevosaurus cambrica Neosphenodontia Brachyrhinodon taylori Colobops noviportensis Sphenodontidae Sphenodon punctatus Cynosphenodon huizachalensis Sphenovipera jimmysjoyi Kawasphenodon expectatus Kawasphenodon peligrensis Pelecymala robustus Eilenodontinae Fraserosphenodon latidens Opisthias rarus Eilenodon robustus Sphenotitan leyesi Toxolophosaurus cloudi Priosphenodon avelasi Leptorhynchia Homoeosaurus maximiliani Kallimodon pulchellus Sigmala sigmala Vadasaurus herzogi Pleurosauridae Palaeopleurosaurus posidonae Pleurosaurus goldfussi Pleurosaurus ginsburgi Kallimodon cerinensis Sapheosauridae Sapheosaurus thiollierei Ankylosphenodon pachyostosus Oenosaurus muehlheimensisReferences edit a b Sues H D Reisz R 1995 First record of the early mesozoic sphenodontian clevosaurus lepidosauria rhynchocephalia from the southern hemisphere Journal of Paleontology 69 1 123 126 Bibcode 1995JPal 69 123S doi 10 1017 s0022336000026974 S2CID 131414921 A new sphenodontian from Brazil is the oldest record of the group in Gondwana phys org Retrieved 2019 08 15 a b Chambi Trowell Sofia A V Martinelli Agustin G Whiteside David I Vivar Paulo R Romo de Soares Marina Bento Schultz Cesar L Gill Pamela G Benton Michael J Rayfield Emily J 2021 06 03 The diversity of Triassic South American sphenodontians a new basal form clevosaurs and a revision of rhynchocephalian phylogeny Journal of Systematic Palaeontology 19 11 787 820 Bibcode 2021JSPal 19 787C doi 10 1080 14772019 2021 1976292 hdl 1983 af14affc a26e 426b 83ca e1833e355882 ISSN 1477 2019 S2CID 240487298 W E Swinton 1939 A new Triassic rhynchocephalian from Gloucestershire Annals and Magazine of Natural History Zoology Botany and Geology 4 591 594 Whiteside D I Chambi Trowell S A V Benton M J 2022 A Triassic crown squamate Science Advances 8 48 eabq8274 Bibcode 2022SciA 8 8274W doi 10 1126 sciadv abq8274 hdl 1983 a3c7a019 cfe6 4eb3 9ac0 d50c61c5319e ISSN 2375 2548 PMID 36459546 a b Keeble Emily Whiteside David I Benton Michael J April 2018 The terrestrial fauna of the Late Triassic Pant y ffynnon Quarry fissures South Wales UK and a new species of Clevosaurus Lepidosauria Rhynchocephalia Proceedings of the Geologists Association 129 2 99 119 Bibcode 2018PrGA 129 99K doi 10 1016 j pgeola 2017 11 001 hdl 1983 5afdc677 3ea0 4519 813d 6052ef8370ec a b Chambi Trowell Sofia A V Whiteside David I Benton Michael J Rayfield Emily J 16 June 2020 Lautenschlager Stephan ed Biomechanical properties of the jaws of two species of Clevosaurus and a reanalysis of rhynchocephalian dentary morphospace Palaeontology 63 6 919 939 Bibcode 2020Palgy 63 919C doi 10 1111 pala 12493 ISSN 0031 0239 S2CID 220902843 Bonaparte J F Sues H D 2006 A new species of clevosaurus lepidosauria rhynchocephalia from the upper Triassic of Rio Grande do Sul Brazil Palaeontology 49 1 917 923 Bibcode 2006Palgy 49 917B doi 10 1111 j 1475 4983 2006 00568 x S2CID 26483165 Saila Laura K 2005 A new species of the sphenodontian reptile Clevosaurus from the Lower Jurassic of South Wales Palaeontology 48 4 817 831 Bibcode 2005Palgy 48 817S doi 10 1111 j 1475 4983 2005 00486 x Hsiou Annie S Nydam Randall L Simoes Tiago R Pretto Flavio A Onary Silvio Martinelli Agustin G Liparini Alexandre Martinez Paulo R Romo de Vivar Soares Marina B Schultz Cesar L Caldwell Michael W 2019 08 14 A New Clevosaurid from the Triassic Carnian of Brazil and the Rise of Sphenodontians in Gondwana Scientific Reports 9 1 11821 Bibcode 2019NatSR 911821H doi 10 1038 s41598 019 48297 9 ISSN 2045 2322 PMC 6694142 PMID 31413294 Klein Catherine G Whiteside David I de Lucas Victor Selles Viegas Pedro A Benton Michael J 2015 A distinctive Late Triassic microvertebrate fissure fauna and a new species of Clevosaurus Lepidosauria Rhynchocephalia from Woodleaze Quarry Gloucestershire UK Proceedings of the Geologists Association 126 3 402 416 Bibcode 2015PrGA 126 402K doi 10 1016 j pgeola 2015 05 003 Bhat Mohd Shafi Datta Debajit Ray Sanghamitra Datta P M 2023 01 02 A new clevosaurid Lepidosauria Rhynchocephalia from the Upper Triassic of IndiaCitation for this article Bhat M S Datta D Ray S amp Datta P M 2023 A new clevosaurid Lepidosauria Rhynchocephalia from the Upper Triassic of India Journal of Vertebrate Paleontology Journal of Vertebrate Paleontology 43 1 Bibcode 2023JVPal 43E2833B doi 10 1080 02724634 2023 2232833 ISSN 0272 4634 S2CID 260525273 Jones MEH 2006 The Early Jurassic clevosaurs from China Diapsida Lepidosauria New Mex Museum Nat Hist Sci Bull 37 548 562 a b Annie Schmaltz Hsiou Marco Aurelio Gallo De Franca Jorge Ferigolo 2015 New Data on the Clevosaurus Sphenodontia Clevosauridae from the Upper Triassic of Southern Brazil PLOS ONE 10 9 e0137523 Bibcode 2015PLoSO 1037523H doi 10 1371 journal pone 0137523 PMC 4565693 PMID 26355294 a b Jorge A Herrera Flores Thomas L Stubbs Armin Elsler Michael J Benton 2018 Taxonomic reassessment of Clevosaurus latidens Fraser 1993 Lepidosauria Rhynchocephalia and rhynchocephalian phylogeny based on parsimony and Bayesian inference Journal of Paleontology 92 4 734 742 Bibcode 2018JPal 92 734H doi 10 1017 jpa 2017 136 hdl 1983 59126b60 16d8 46d2 b657 954693a39d4e DeMar David G Jones Marc E H Carrano Matthew T 2022 12 31 A nearly complete skeleton of a new eusphenodontian from the Upper Jurassic Morrison Formation Wyoming USA provides insight into the evolution and diversity of Rhynchocephalia Reptilia Lepidosauria Journal of Systematic Palaeontology 20 1 1 64 doi 10 1080 14772019 2022 2093139 hdl 2440 136608 ISSN 1477 2019 S2CID 252325953 Additional reading editPaleofile Gill PG Saila LK Corfe IJ Challands TJ Williams M Clemens WA 2006 The fauna and palaeoenvironment of St Brides Island Evidence from the lower Jurassic fissure fills of South Wales In Barrett PM Evans SE eds Ninth international symposium on Mesozoic terrestrial ecosystems and biota pp 48 51 London Natural History Museum Jones MEH 2006 The Early Jurassic clevosaurs from China Diapsida Lepidosauria Natl Mus Nat Hist Sci Bull 37 548 562 Jones MEH 2009 Dentary tooth shape in Sphenodon and its fossil relatives Diapsida Lepidosauria Rhynchocephalia In Koppe T Meyer G Alt KW eds Interdisciplinary Dental Morphology Frontiers of Oral Biology vol 13 Greifswald Germany Karger 9 15 nbsp Paleontology portal Retrieved from https en wikipedia org w index php title Clevosaurus amp oldid 1214157316, wikipedia, wiki, book, books, library,
