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Journal of Iberian Geology

, Volume 45, Issue 2, pp 317–340 | Cite as

Taxonomy, morphometry and morphospace of cranial bones of Panthasaurus gen. nov. maleriensis from the Late Triassic of India

  • Sanjukta ChakravortiEmail author
  • Dhurjati Prasad Sengupta
Research Paper

Abstract

Metoposaurids are an important Late Triassic temnospondyl family known from nonmarine sediments of Europe, North-America, North Africa and India. Indian taxon Metoposaurus maleriensis became Buettneria maleriensis. “Metoposaurus” was thereafter restricted to encompass only M. diagnosticus from Germany and M. bakeri from North America, whose lacrimals are excluded from the orbital margin. However, some specimens of M. diagnosticus also exhibit lacrimals contributing to the orbital margins, as in Buettneria. Also, the generic name Buettneria was preoccupied, and Koskinonodon represents the senior synonym. Hence, the taxonomic status of the Indian metoposaurids became questionable. Metoposaurids being extremely conservative in nature, no single character could be assigned to distinguish them at the species level and there is no alpha level taxonomy available. Assigning a taxonomic status of the Indian taxon along with alpha taxonomy of all the other metoposaurids viewed through the lights of morphometry and morphospace is the main purpose of this paper. All genera were studied first hand from different museums of the world. Detailed measurements of skull bones and morphological properties are critically appraised. Biometric studies were done to analyse the variation between different taxa. Morphospace of different bones are constructed after conducting elliptical Fourier analysis and PCA using R. Cladogram using TNT and comparison of the cranial morphology is provided. Fourteen parsimonious trees, 50% majority rule consensus, Bremer support value and bootstrap resampling all reveals that Indian taxon occupies a distinct position somewhere between the European Metoposaurus and North American Koskinonodon. This fact corroborates with the morphospace analysis. There is also a strong bio geographic correlation in the fact that the Indian taxon was widely separated from the main cluster of the European and the North American taxa. Panthasaurus gen. nov. maleriensis is erected for the Indian taxon of metoposaurids. Biometry and morphospace studies supports Indian Metoposaurus to be a separate taxon.

Keywords

Metoposauridae India Morphometry Morphospace Taxonomy 

Resumen

Los metoposáuridos son una importante familia de temnospóndilos del Triásico Superior conocida de sedimentos no marinos de Europa, Norte América, Norte de África e India. El taxón Indio Metoposaurus maleriensis se convirtió en Buettneria maleriensis. “Metoposaurus” fue posteriormente restringido para englobar solamente M. diagnosticus de Alemania y M.bakeri de Norte América, cuyos lacrimales están excluidos del margen orbital. Sin embargo, algunos especímenes de M. diagnosticus también exhiben lacrimales que contribuyen a los márgenes orbitales, como en Buettneria. Además, el nombre genérico Buettneria era presentaba problemas, dado que Koskinonodon es el sinónimo juvenil. Por lo tanto, el estatus taxonómico de los metoposáuridos indios se convirtió en cuestionable. Los metoposáuridos, siendo de naturaleza extremadamente conservadora, no presentan un solo carácter que pueda ser asignado para distinguirlos a nivel de especie y no se dispone de una taxonomía alfa para este grupo. Asignar un estatus taxonómico al taxón Indio junto con una taxonomía alfa del resto de metoposáuridos vista a través de la luz de la morfometría y morfoespacio son los principales propósitos de este artículo. Los géneros, procedentes de diferentes museos de todo el mundo, fueron estudiados por primera vez. Las medidas de detalle de los huesos craneales y propiedades, morfológicas han sido evaluadas críticamente. Los estudios biométricos fueron también realizados para analizar la variación entre diferentes taxones. El morfoespacio de diferentes huesos fue construido después de realizar análisis elípticos de Fourier y PCA usando R. Se presentan cladogramas usando TNT y comparación de la morfología craneal. Catorce arboles parsimoniosos, regla del cincuenta por ciento del consenso de la mayoría, valores de Bremer Support y remuestreo por bootstrap revelan en todos los casos que el taxón Indio ocupa una posición distinta en algún lugar entre el taxón europeo Metoposaurus y el taxón norteamericanos Koskinonodon. Este hecho se corrobora con los análisis de morfoespacio. Existe también una fuerte correlación biogeográfica en el hecho que el taxón Indio está ampliamente separado del clúster principal de los taxones europeos y norteamericanos. Panthasaurus gen. nov. maleriensis se erige como el taxón Indio de metoposáuridos. Estudios biométricos y de morfoespacio soportan que los metoposáuridos Indios correspondan a un taxón separado.

Palabras clave

Metoposauridae India Morfometría Morfoespacio Taxonomía 

Notes

Acknowledgements

One of the authors (SC) acknowledges the authorities of MNHN, Paris including Dr. Damien Germain for allowing us to study their collection. SC thanks Dr. Josep Fortuny for sharing his images with us thereby enriching our data. SC also thanks Dr. Brussate and Dr. Sulej for sharing their images. SC acknowledges Dr. Julien Claude for his help in R and for other useful advice. She also thanks Thomas Arbez for all his support during her stay. The authors thank the organisers of the special seminar on “Early tetrapods awaken—New insights into the evolution of temnospondyls” as a part of the European Association of Vertebrate Paleontologists annual meeting at Harlem, 2016. The authors also thank the reviewers Josep Fortuny, Bryan G and a third reviewer whose critical comments enriched the manuscript. They also thank the authorities of the Indian Statistical Institute for funding and for providing infrastructural support. DPS wants to acknowledge the late Prof. T. K. Roychowdhury of Indian Statistical Institute for introducing him to the world of the metoposaurid amphibians.

Supplementary material

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Supplementary material 1 (DOCX 5035 kb)

References

  1. Bandyopadhyay, S., & Sengupta, D. P. (2006). Vertebrate faunal turnover during the Triassic–Jurassic transition: An Indian scenario. New Mexico Museum of Natural History & Science Bulletin, 37, 77–85.Google Scholar
  2. Bonhomme, V. (2012). A graphical introduction to Momocs and outline analysis using R. Pondicherry: French Institute of Pondicherry.Google Scholar
  3. Bonhomme, V., Picq, S., Gaucherel, C., & Claude, J. (2014). Momocs: Outline analysis using R. Journal of Statistical Software, 56(13), 1–24.CrossRefGoogle Scholar
  4. Branson, E. B. (1905). Structure and relationships of American Labyrinthodontidae. The Journal of Geology, 13(7), 568–610.CrossRefGoogle Scholar
  5. Brusate, S. L., Butler, R. J., Mateus, O., & Steyer, J. S. (2015). A new species of Metoposaurus from the Late Triassic of Portugal and comments on the systematics and biogeography of metoposaurid temnospondyls. Journal of Vertebrate Paleontology, 35(3), e912988.CrossRefGoogle Scholar
  6. Case, E. C. (1922). New reptiles and stegocephalians from the Upper Triassic of western Texas (Vol. 321, pp. 1–84). Washington: Carnegie Institution of Washington.CrossRefGoogle Scholar
  7. Case, E. C. (1931). Description of a new species of Buettneria, with a discussion of the brain case. In: Contributions from the Museum of Paleontology, University of Michigan (Vol. 3(11), pp. 187–206). Ann Arbor: University of Michigan Press.Google Scholar
  8. Case, E. C. (1932). A collection of stegocephalians from Scurry County, Texas (Vol. 4, pp. 1–56). Ann Arbor: University of Michigan Press.Google Scholar
  9. Charrad, M., Ghazzali, N., Boiteau, V., Niknafs, A., & Charrad, M. M. (2014). Package ‘NbClust’. Journal of Statistical Software, 61, 1–36.CrossRefGoogle Scholar
  10. Claude, J. (2008). Morphometrics with R. Berlin: Springer Science & Business Media.Google Scholar
  11. Colbert, E. H. (1958). Relationships of the Triassic Maleri fauna. Journal of the Paleontological Society of India, 3, 68–81.Google Scholar
  12. Colbert, E. H., & Imbrie, J. (1956). Triassic metoposaurid amphibians. Bulletin of the AMNH, 110(6), 405–452.Google Scholar
  13. Dutuit, J. M. (1976). Introduction à l’étude paléontologique du Trias continental marocain. Description des premiersstegocephalesrecueillisdans le couloir d’Argana (Atlas occidental). Memoires du Museum National d’HistoireNaturelle, Paris, Series C, 36, 1–253.Google Scholar
  14. Dutuit, J. M. (1978). Description de quelques fragments osseux provenant de la région de Folakara (Trias supérieur malgache). Bulletin de Museum Nationale d’Histoire naturelle, Paris. Series III, 516, 79–89.Google Scholar
  15. Fortuny, J., Marcé-Nogué, J., & Konietzko-Meier, D. (2017). Feeding biomechanics of Late Triassic metoposaurids (Amphibia: Temnospondyli): A 3D finite element analysis approach. Journal of Anatomy, 230(6), 752–765.CrossRefGoogle Scholar
  16. Fraas, E. (1913). Neue Labyrinthodontenaus der SchwäbischenTrias. Palaeontographica, 60, 275–294.Google Scholar
  17. Gee, B. M., Parker, W. G., & Marsh, A. D. (2017). Microanatomy and paleohistology of the intercentra of North American metoposaurids from the Upper Triassic of Petrified Forest National Park (Arizona, USA) with implications for the taxonomy and ontogeny of the group. PeerJ, 5, e3183.CrossRefGoogle Scholar
  18. Goloboff, P. A., Farris, J. S., & Nixon, K. C. (2008). TNT, a free program for phylogenetic analysis. Cladistics, 24(5), 774–786.CrossRefGoogle Scholar
  19. Gregory, J. T. (1980). The otic notch of metoposaurid labyrinthodonts. Aspects of vertebrate history (pp. 125–135). Flagstaff: Museum of Northern Arizona Press.Google Scholar
  20. Hunt, A. P. (1989). Late Triassic vertebrate localities in New Mexico. In: Lucas, S. G., & Hunt, A. P. (Eds.), Dawn of the age of dinosaurs in the American Southwest. New Mexico museum of natural history and science (pp. 72–101). Albuquerque: New Mexico Museum of Natural History.Google Scholar
  21. Hunt, A. P. (1993). Revision of the Metoposauridae (Amphibia: Temnospondyli) and description of a new genus from Western North America. Museum of Northern Arizona Bulletin, 59, 67–97.Google Scholar
  22. Kassambara, A. (2017). A practical guide to cluster analysis in R: Unsupervised machine learning (Vol. 1, pp. 0–147). STHDA.Google Scholar
  23. Kaufman, L., & Rousseeuw, P. J. (1990). Partitioning around medoids (program PAM). In: Finding groups in data: an introduction to cluster analysis, Wiley Series in Probability and Statistics (pp. 68–125). Wiley.Google Scholar
  24. Kodinariya, T. M., & Makwana, P. R. (2013). Review on determining number of Cluster in K-Means Clustering. International Journal, 1(6), 90–95.Google Scholar
  25. Konietzko-Meier, D., Gruntmejer, K., Marcé-Nogué, J., Bodzioch, A., & Fortuny, J. (2018). Merging cranial histology and 3D-computational biomechanics: a review of the feeding ecology of a Late Triassic temnospondyl amphibian. PeerJ, 6, e4426.CrossRefGoogle Scholar
  26. Kuhn, O. (1933). Labyrinthodonten und Parasuchier aus dem mittleren Keuper von Ebrach in Oberfranken. Neues Jahrbuch fur Mineralo- €gie, Geologie und Pal€aontologie, Beilage-Band, Abteilung B, 69, 94–144.Google Scholar
  27. Long, R. A., & Murry, P. A. (1995). Late Triassic (Carnian and Norian) tetrapods from the Southwestern United States: Bulletin 4 (Vol. 4). Albuquerque: New Mexico Museum of Natural History and Science.Google Scholar
  28. Lucas, S. G., Rinehart, L. F., Heckert, A. B., Hunt, A. P., & Spielmann, J. A. (2016). Rotten Hill: A Late Triassic bonebed in the Texas Panhandle, USA. New Mexico Museum of Natural History and Science Bulletin, 72, 1–97.Google Scholar
  29. McGhee, G. R. (1999). Theoretical morphology: The concept and its applications. Columbia: Columbia University Press.Google Scholar
  30. McHugh, J. B. (2012). Temnospondyl ontogeny and phylogeny, a window into terrestrial ecosystems during the Permian–Triassic mass extinction. Ph.D. Dissertation, The University of Iowa.Google Scholar
  31. Meyer, E. (1842). Labyrinthodonten—Genera. Neues Jahrbuchfür Mineralogie, Geographie, Geologie, Paläeontologie, 1842, 301–330.Google Scholar
  32. Milner, A. R. (1990). The radiation of temnospondyl amphibians. In P. D. Taylor & G. P. Larwood (Eds.), Major evolutionary radiations (pp. 321–349). Oxford: Clarendon Press.Google Scholar
  33. Milner, A. R., & Schoch, R. R. (2004). The latest metoposaurid amphibians from Europe. (With 4 figures). Neues Jahrbuch fur Geologie und Palaontologie-Abhandlungen, 232(2–3), 231–252.Google Scholar
  34. Milner, A. R. (1994). Late Triassic and Jurassic amphibians: fossil record and phylogeny. In: Fraser, N. C., & Sues, H.-D. (eds) In the shadow of the dinosaurs: Early Mesozoic Tetrapods (pp. 5–22). Cambridge: Cambridge University Press.Google Scholar
  35. Mueller, B. D. (2007). Koskinonodon Branson and Mehl, 1929, a replacement name for the preoccupied temnospondyl Buettneria Case, 1922. Journal of Vertebrate Paleontology, 27(1), 225-225.CrossRefGoogle Scholar
  36. Novas, F. E., Ezcurra, M. D., Chatterjee, S., & Kutty, T. S. (2010). New dinosaur species from the Upper Triassic Upper Maleri and Lower Dharmaram formations of central India. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 101(3–4), 333–349.CrossRefGoogle Scholar
  37. Romer, A. S. (1947). Review of the Labyrinthodontia. Museum of Comparative Zoology, Harvard, 99(1), 1–368.Google Scholar
  38. RoyChowdhury, T. R. (1965). A new metoposaurid amphibian from the Upper Triassic Maleri Formation of Central India. Philosophical Transactions of the Royal Society of London B, 250, 1–52.CrossRefGoogle Scholar
  39. Sawin, H. J. (1945). Amphibians from the Dockum Triassic of Howard County, Texas. University of Texas Publication, 4401, 361–399.Google Scholar
  40. Schoch, R. R. (2008). A new stereospondyl from the German Middle Triassic, and the origin of the Metoposauridae. Zoological Journal of the Linnean Society, 152(1), 79–113.CrossRefGoogle Scholar
  41. Schoch, R. R. (2013). The evolution of major temnospondyl clades: an inclusive phylogenetic analysis. Journal of Systematic Palaeontology, 11(6), 673–705.CrossRefGoogle Scholar
  42. Schoch, R. R. (2014). Amphibian evolution: the life of early land vertebrates. New York: Wiley.CrossRefGoogle Scholar
  43. Schoch, R. R., & Milner, A. R. (2000). Handbuch der Palaoherpetologie 3B: Stereospondyli. München: Pfeil.Google Scholar
  44. Sengupta, D. P. (1992). Metoposaurus maleriensis Roychowdhury from the Tiki Formation of Son—Mahanadi Valley of Central India. Indian Journal of Geology, 64, 300–305.Google Scholar
  45. Sengupta, D. P. (2002). Indian metoposaurid amphibians revised. Paleontological Research, 6, 41–65.Google Scholar
  46. Sengupta, D. P. (2003). Triassic temnospondyls of the Pranhita–Godavari basin, India. Journal of Asian Earth Sciences, 21(6), 655–662.CrossRefGoogle Scholar
  47. Spielmann, J. A., & Lucas, S. G. (2012). Tetrapod fauna of the Upper Triassic Redonda Formation east-central New Mexico: The characteristic assemblage of the Apachean Land-vertebrate Faunachron: Bulletin 55 (Vol. 55). Albuquerque: New Mexico Museum of Natural History and Science.Google Scholar
  48. Sues, H.-D., & Olsen, P. E. (2015). Stratigraphic and temporal context and faunal diversity of Permian–Jurassic continental tetrapod assemblages from the Fundy rift basin, eastern Canada. Atlantic Geology, 51, 139–205.CrossRefGoogle Scholar
  49. Sulej, T. (2002). Species discrimination of the Late Triassic temnospondyl amphibian Metoposaurus diagnosticus. Acta Palaeontologica Polonica, 47, 535–546.Google Scholar
  50. Sulej, T. (2007). Osteology, variability, and evolution of Metoposaurus, a temnospondyl from the Late Triassic of Poland. Palaeontologia Polonica, 64, 29–139.Google Scholar
  51. Teschner, E. M., Sander, P. M., & Konietzko-Meier, D. (2018). Variability of growth pattern observed in Metoposaurus krasiejowensis humeri and its biological meaning. Journal of Iberian Geology, 44(1), 99–111.CrossRefGoogle Scholar
  52. Watson, D. M. S. (1919). The structure, evolution and origin of the Amphibia. The orders Rhachitomi and Stereospondyli. Philosophical Transactions of the Royal Society of London. Series B, 209, 1–73.CrossRefGoogle Scholar
  53. Wilson, J. A. (1941). An interpretation of the skull of Buettneria, with special reference to the cartilages and soft parts: Contributions from the Museum of Paleontology (vol. 6, pp. 71–111). University of Michigan.Google Scholar
  54. Yates, A. M., & Warren, A. A. (2000). The phylogeny of the ‘higher’ temnospondyls (Vertebrata: Choanata) and its implications for the monophyly and origins of the Stereospondyli. Zoological Journal of the Linnean Society, 128(1), 77–121.CrossRefGoogle Scholar
  55. Zittel, K. A. (1888). Handbuch der Paläeontologie. Abteilung 1.PaläozoologieBand III. Vertebrata (Pisces, Amphibia, Reptilia, Aves) (pp. 1–90). München: Oldenbourg.Google Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Indian Statistical InstituteKolkataIndia

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