Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-19T23:01:48.369Z Has data issue: false hasContentIssue false

A new early-diverging sphenodontian (Lepidosauria, Rhynchocephalia) from the Upper Triassic of Virginia, U.S.A.

Published online by Cambridge University Press:  10 November 2020

Hans-Dieter Sues
Affiliation:
Department of Paleobiology, National Museum of Natural History, MRC 121, P.O. Box 37012, Washington, DC20013-7012, USA
Rainer R. Schoch
Affiliation:
Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, D-70191Stuttgart, Germany

Abstract

A new taxon of sphenodontian reptile, Micromenodon pitti new genus new species is described from the Upper Triassic (Carnian) Vinita Formation of the Richmond basin of the Newark Supergroup in Virginia. It is diagnosed by a dorsoventrally deep facial process of the maxilla that extends for almost the entire anteroposterior length of the bone and by obtusely conical, strongly ribbed additional teeth in the maxilla that comprise a greatly enlarged tooth followed by smaller teeth posteriorly. Phylogenetic analysis found Micromenodon pitti n. gen. n. sp. as an early-diverging sphenodontian with fully acrodont tooth implantation. The maxillary dentition appears functionally suited for processing hard arthropod exoskeletons and snail shells.

UUID: http://zoobank.org/40ed7cb6-4867-464b-8bfb-db07febfe97c

Type
Articles
Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press on behalf of The Paleontological Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Apesteguía, S., Gómez, R.O., and Rougier, G.W., 2014, The youngest South American rhynchocephalian, a survivor of K/Pg extinction: Proceedings of the Royal Society, Series B, v. 281, n. 20140811. doi:10.1098/rspb.2014.0811.Google ScholarPubMed
Benton, M.J., and Walker, A.D., 1985, Palaeoecology, taphonomy, and dating of Permo-Triassic reptiles from Elgin, north-east Scotland: Palaeontology, v. 28, p. 207234.Google Scholar
Carroll, R.L., 1985, A pleurosaur from the Lower Jurassic and the taxonomic position of Sphenodontia: Palaeontographica, Abteilung A, vol. 189, p. 128.Google Scholar
Cree, A., 2014, Tuatara: Biology and Conservation of a Venerable Survivor: Canterbury, New Zealand, Canterbury University Press, 583 p.Google Scholar
Deutsche Stratigraphische Kommission, ed., 2005, Stratigraphie von Deutschland. IV—Keuper: Courier Forschungsinstitut Senckenberg, v. 253, 296 p.Google Scholar
Estes, R., and Williams, E.E., 1984, Ontogenetic variation in the molariform teeth of lizards: Journal of Vertebrate Paleontology, v. 4, p. 96107.CrossRefGoogle Scholar
Evans, S.E., 1980, The skull of a new eosuchian reptile from the Lower Jurassic of South Wales: Zoological Journal of the Linnean Society, v. 70, p. 203264.CrossRefGoogle Scholar
Evans, S.E., 1998, Crown group lizards from the Middle Jurassic of Britain: Palaeontographica, Abteilung A, v. 250, p. 123154.Google Scholar
Fraser, N.C., 1982, A new rhynchocephalian from the British Upper Trias: Palaeontology, v. 25, p. 709725.Google Scholar
Fraser, N.C., 1988, The osteology and relationships of Clevosaurus (Reptilia: Sphenodontida): Philosophical Transactions of the Royal Society of London, Series B, v. 321, p. 125178.Google Scholar
Fraser, N.C., and Benton, M.J., 1989, The Triassic reptiles Brachyrhinodon and Polysphenodon and the relationships of sphenodontids: Zoological Journal of the Linnean Society, v. 96, p. 413445.CrossRefGoogle Scholar
Fraser, N.C., and Shelton, C.G., 1988, Studies of tooth implantation in fossil tetrapods using high-resolution X-radiography: Geological Magazine, v. 125, p. 117122.CrossRefGoogle Scholar
Gauthier, J.A., Estes, R., and de Queiroz, K., 1988, A phylogenetic analysis of Lepidosauromorpha, in Estes, R., and Pregill, G., eds., Phylogenetic Relationships of the Lizard Families: Essays Commemorating Charles L. Camp: Stanford, California, Stanford University Press, p. 1598.Google Scholar
Gray, J.E., 1842, Description of two hitherto unrecorded species of reptiles from New Zealand; presented to the British Museum by Dr. Dieffenbach: The Zoological Miscellany, n. 4, p. 72.Google Scholar
Gray, J.E., 1845, Catalogue of the Specimens of Lizards in the Collection of the British Museum: London, Printed by Order of the Trustees by Edward Newman, 289 p.Google Scholar
Günther, A., 1867, Contribution to the anatomy of Hatteria (Rhynchocephalus, Owen): Philosophical Transactions of the Royal Society of London, v. 157, p. 595629.Google Scholar
Haeckel, E., 1866, Generelle Morphologie der Organismen. Allgemeine Grundzüge der organischen Formen-Wissenschaft, mechanisch begründet durch die von Charles Darwin reformirte Descendenz-Theorie. V. 2: Berlin, Verlag von Georg Reimer, 462 p.Google Scholar
Heckert, A.B., 2004, Late Triassic microvertebrates from the lower Chinle Group (Otischalkian-Adamanian: Carnian), southwestern U.S.A.: New Mexico Museum of Natural History & Science Bulletin, v. 27, 170 p.Google Scholar
Herrera-Flores, J.A., Stubbs, T.L., Elsler, A., and Benton, M.J., 2019, Taxonomic reassessment of Clevosaurus latidens Fraser, 1993 (Lepidosauria, Rhynchocephalia) and rhynchocephalian phylogeny based on parsimony and Bayesian inference: Journal of Paleontology, v. 92, p. 734742.CrossRefGoogle Scholar
Hsiou, A.S., de França, M.A.G., and Ferigolo, J., 2015, New data on the Clevosaurus (Sphenodontia: Clevosauridae) from the Upper Triassic of southern Brazil: PLoS ONE 10(9), n. 0137523. doi:10.1371/journal.pone.0137523.CrossRefGoogle ScholarPubMed
Hsiou, A.S., Nydam, R.L., Simões, T.R., Pretto, F.A., Onary, S., Martinelli, A.G., Liparini, A., de Vivar Martínez, P.R.R., Soares, M.B., Schultz, C.L., and Caldwell, M.W., 2019, A new clevosaurid from the Triassic (Carnian) of Brazil and the rise of sphenodontians in Gondwana: Scientific Reports 9, n. 11821. doi:10.1038/s41598-019-48297-9.CrossRefGoogle ScholarPubMed
Huber, P., Lucas, S.G., and Hunt, A.P., 1993, Vertebrate biochronology of the Newark Supergroup, Triassic, eastern North America: New Mexico Museum of Natural History and Science Bulletin, v. 3, p. 179186.Google Scholar
Huene, F. von, 1910, Über einen echten Rhynchocephalen aus der Trias von Elgin, Brachyrhinodon Taylori: Neues Jahrbuch für Mineralogie, Geologie und Paläontologie, Jahrgang 1910, v. 2, p. 2962.Google Scholar
Jaekel, O., 1911, Die Wirbeltiere. Eine Übersicht über die fossilen und lebenden Formen: Berlin, Verlag von Gebrüder Borntraeger, 252 p.CrossRefGoogle Scholar
Jenkins, K.M., Jones, M.E.H., Zikmund, T., Boyde, A., and Daza, J.D., 2017, A review of tooth implantation among rhynchocephalians (Lepidosauria): Journal of Herpetology, v. 51, p. 300306.CrossRefGoogle Scholar
Jones, M.E.H., 2008, Skull shape and feeding strategy in Sphenodon and other Rhynchocephalia (Diapsida: Lepidosauria): Journal of Morphology, v. 269, p. 945966.CrossRefGoogle Scholar
Jones, M.E.H., 2009, Dentary tooth shape in Sphenodon and its fossil relatives (Diapsida: Lepidosauria: Rhynchocephalia): Frontiers of Oral Biology, v. 13, p. 915.CrossRefGoogle Scholar
Jones, M.E.H., Curtis, N., Fagan, M.J., O'Higgins, P., and Evans, S.E., 2011, Hard tissue anatomy of the cranial joints in Sphenodon (Rhynchocephalia): sutures, kinesis, and skull mechanics: Palaeontologia Electronica, article 14.2.17A, 92 p. palaeo-electronica.org/2011_2/251/index.html.Google Scholar
Jones, M.E.H., Anderson, C.L., Hipsley, C.A., Müller, J., Evans, S.E., and Schoch, R.R., 2013, Integration of molecules and new fossils supports a Triassic origin for Lepidosauria (lizards, snakes, and tuatara): BMC Evolutionary Biology, v. 13, n. 208. doi:10.1186/1471-2148-13-208.CrossRefGoogle Scholar
Kent, D.V., Olsen, P.E., and Muttoni, G., 2017, Astrochronostratigraphic polarity time scale (APTS) for the Late Triassic and Early Jurassic from continental sediments and correlation with standard marine stages: Earth-Science Reviews, v. 166, p. 153180.CrossRefGoogle Scholar
Kowalski, J., Bodzioch, A., Janecki, P.A., Ruciński, M.R., and Antczak, M., 2019, Preliminary report on the microvertebrate faunal remains from the Late Triassic locality at Krasiejów, SW Poland: Annales Societatis Geologorum Poloniae, v. 89, p. 291305.Google Scholar
LeTourneau, P.M., 2003, Stratigraphic architecture and paleomagnetic reversal stratigraphy of the Late Triassic Taylorsville Basin, Virginia and Maryland, in LeTourneau, P.M., and Olsen, P.E., eds., The Great Rift Valleys of Pangea in Eastern North America, Volume 2: Sedimentology, Stratigraphy, and Paleontology: New York, Columbia University Press, p. 1258.CrossRefGoogle Scholar
Martínez, R.N., Apaldetti, C., Colombi, C.E., Praderio, A., Fernandez, E., Malnis, P.S., Correa, G.A., Abelin, D., and Alcober, O., 2013, A new sphenodontian (Lepidosauria: Rhynchocephalia) from the Late Triassic of Argentina and the early origin of the herbivore opisthodontians: Proceedings of the Royal Society, Series B, v. 280, n. 20132057. doi:10.1098/rspb.2013.2057.Google ScholarPubMed
Martz, J.W., and Parker, W.G., 2017, Revised formulation of the Late Triassic Land Vertebrate “Faunachrons” of western North America: recommendations for codifying nascent systems of vertebrate biochronology, in Zeigler, K.E., and Parker, W.G., eds., Terrestrial Depositional Systems: Deciphering Complexities through Multiple Stratigraphic Methods: Amsterdam, Elsevier, p. 39124.Google Scholar
Olsen, P.E., Kent, D.V., and Whiteside, J.H., 2011, Implications of the Newark Supergroup-based astrochronology and geomagnetic polarity time scale (Newark-APTS) for the tempo and mode of the early diversification of the Dinosauria: Earth and Environmental Science Transactions of the Royal Society of Edinburgh, v. 101, p. 201229.CrossRefGoogle Scholar
Robinson, P.L., 1976, How Sphenodon and Uromastyx grow their teeth and use them, in Bellairs, A.d'A., and Cox, C.B., eds., Morphology and Biology of Reptiles: London, Academic Press, p. 4364.Google Scholar
Schoch, R.R., 2015, Reptilien des Lettenkeupers, in Hagdorn, H., Schoch, R., and Schweigert, G., eds., Der Lettenkeuper—Ein Fenster in die Zeit vor den Dinosauriern: Stuttgart and Ingelfingen, Palaeodiversity—Sonderband, p. 231264.Google Scholar
Sues, H.-D., and Fraser, N.C., 2010, Triassic Life on Land: The Great Transition: New York, Columbia University Press, 236 p.Google Scholar
Sues, H.-D., Olsen, P.E., and Kroehler, P.A., 1994, Small tetrapods from the Upper Triassic of the Richmond basin of Virginia, in Fraser, N.C., and Sues, H.-D., eds., In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods: New York, Cambridge University Press, p. 161170.Google Scholar
Whiteside, D.I., 1986, The head skeleton of the Rhaetian sphenodontid Diphydontosaurus avonis gen. et sp. nov. and the modernizing of a living fossil: Philosophical Transactions of the Royal Society of London, Series B, v. 312, p. 379430.Google Scholar
Whiteside, D.I., and Duffin, C.J., 2017, Late Triassic terrestrial microvertebrates from Charles Moore's ‘Microlestes’ quarry, Holwell, Somerset, UK: Zoological Journal of the Linnean Society, v. 179, p. 677705.CrossRefGoogle Scholar
Whiteside, D.I., Duffin, C.J., and Furrer, H., 2017, The Late Triassic lepidosaur fauna from Hallau, north-eastern Switzerland, and a new ‘basal’ rhynchocephalian Deltadectes elvetica gen. et sp. nov.: Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen, v. 285, p. 5374.CrossRefGoogle Scholar
Williston, S.W., 1925, The Osteology of the Reptiles: Cambridge, Massachusetts, Harvard University Press, 300 p.Google Scholar