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A new Pliosaurus species (Sauropterygia, Plesiosauria) from the Upper Jurassic of Patagonia: new insights on the Tithonian morphological disparity of mandibular symphyseal morphology

  • José P. O’Gorman (a1) (a2), Zulma Gasparini (a1) (a2) and Luis A. Spalletti (a2) (a3)

Most species of the genus Pliosaurus Owen, 1842 come from the Northern Hemisphere, however, a growing number of new specimens are now available from the Southern Hemisphere. Here, a new species of Pliosaurus is described, the second for the genus from the Southern Hemisphere, collected from the upper Tithonian (Jurassic) levels of the Vaca Muerta Formation, Neuquén Province, Patagonia. Pliosaurus almanzaensis new species is characterized by two autapomophies: the angular participating in the mandibular symphysis and the occipital condyle without a notochordal pit or several, irregularly arranged grooves. Additionally, P. almanzaensis n. sp. can be differentiated from other Pliosaurus species by the following characters: trihedral teeth, nine or more symphyseal alveoli, 15–17 post-symphyseal alveoli, and the parasphenoid without a ventral keel. Pliosaurus almanzaensis n. sp. shows that Pliosaurus species with nine or more symphyseal alveoli persisted until the late Tithonian, contrary to previous assumptions that only species with six symphyseal alveoli were present.

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Albright, L.B. III, Gillette, D.D., and Titus, A.L., 2007, Plesiosaurs from the Upper Cretaceous (Cenomanian–Turonian) Tropic Shale of southern Utah, part 1: new records of the pliosaur Brachauchenius lucasi : Journal of Vertebrate Paleontology, v. 27, p. 3140.
Barrientos-Lara, J.I., Fernández, M.S., and Alvarado-Ortega, J., 2015, Kimmeridgian pliosaurids (Sauropterygia, Plesiosauria) from Tlaxiaco, Oaxaca, southern Mexico: Revista Mexicana de Ciencias Geológicas, v. 32, p. 293304.
Benson, R.B., and Druckenmiller, P.S., 2014, Faunal turnover of marine tetrapods during the Jurassic-Cretaceous transition: Biological Reviews, v. 89, p. 123.
Benson, R.B., Ketchum, H.F., Noè, L.F., and Gómez‐Pérez, M., 2011, New information on Hauffiosaurus (Reptilia, Plesiosauria) based on a new species from the Alum Shale Member (lower Toarcian: Lower Jurassic) of Yorkshire, UK: Palaeontology, 547571.
Benson, R.B., Evans, M., Smith, A.S., Sassoon, J., Moore-Faye, S., Ketchum, H.F., and Forrest, R., 2013, A giant pliosaurid skull from the Late Jurassic of England: PLoS ONE, v. 8, e65989, doi: 10.1371/journal.pone.0065989.
Bremer, K., 1994, Branch support and tree stability: Cladistics, v. 10, p. 295304.
Buchy, M.C., Frey, E., Stinnesbeck, W., and López-Oliva, J.G., 2003, First occurrence of a gigantic pliosaurid plesiosaur in the Late Jurassic (Kimmeridgian) of Mexico: Bulletin de la Société Géologique de France, v. 174, p. 271278.
Carte, A., and Bailey, W.H., 1863, Description of a new species of Plesiosaurus, from the Lias, near Whitby, Yorkshire: Journal of Royal Dublin Society, v. 4, p. 160170.
de Blainville, H.D., 1835, Description de quelques espèces de reptiles de la Californie, précédée de l’analyse d’un système général d’herpétologie et d’amphibiologie: Nouvelles Archives du Museum d’Histoire Naturelle, v. 4, p. 233296.
Digregorio, R.E., Gulisano, C.A., Gutiérrez Pleimling, A.R., and Minitti, S.A., 1984, Esquema de la evolución geodinámica de la Cuenca Neuquina y sus implicancias paleogeográficas: IX Congreso Geológico Argentino Actas II, S.C. de Bariloche, p. 147162.
Druckenmiller, P.S., and Russell, A.P., 2008, A phylogeny of Plesiosauria (Sauropterygia) and its bearing on the systematic status of Leptocleidus Andrews, 1922: Zootaxa, v. 1863, p. 1120.
Farris, J.S., 1989, The retention index and homoplasy excess: Systematic Biology, v. 38, p. 406407.
Fischer, V., Arkhangelsky, M.S., Stenshin, I.M., Uspensky, G.N., Zverkov, N.G., and Benson, R.B., 2015, Peculiar macrophagous adaptations in a new Cretaceous pliosaurid: Royal Society Open Science, v. 2, 150552, doi: 10.1098/rsos.150552.
Foffa, D., Cuff, A.R., Sassoon, J., Rayfield, E.J., Mavrogordato, M.N., and Benton, M.J., 2014a, Functional anatomy and feeding biomechanics of a giant Upper Jurassic pliosaur (Reptilia: Sauropterygia) from Weymouth Bay, Dorset, UK: Journal of Anatomy, v. 225, p. 209219.
Foffa, D., Sassoon, J., Cuff, A.R., Mavrogordato, M.N., and Benton, M.J., 2014b, Complex rostral neurovascular system in a giant pliosaur: Naturwissenschaften, v. 101, p. 453456.
Gasparini, Z., 2009, A new Oxfordian pliosaurid (Plesiosauria, Pliosauridae) in the Caribbean seaway: Palaeontology, v. 52, p. 661669.
Gasparini, Z., and O’Gorman, J.P., 2014, A new species of Pliosaurus (Sauropterygia, Plesiosauria) from the Upper Jurassic of northwestern Patagonia, Argentina: Ameghiniana, v. 51, p. 269283.
Gasparini, Z.B., Spalletti, L., and de la Fuente, M.S., 1997, Marine reptiles of a Tithonian transgression, Western Neuquén Basin, Argentina: facies and palaeonvironments: Geobios, v. 30, p. 701712.
Goloboff, P.A., and Catalano, S.A., 2016, TNT version 1.5, including a full implementation of phylogenetic morphometrics: Cladistics, v. 32, p. 221238.
Halstead, L.B., 1971, Liopleurodon rossicus (Novozhilov)—a pliosaur from the lower Volgian of the Moscow basin: Palaeontology, v. 14, p. 566570.
Hampe, O., 2005, Considerations on a Brachauchenius skeleton (Pliosauroidea) from the lower Paja Formation (late Barremian) of Villa de Leyva area (Colombia): Fossil Record, v. 8, p. 3751.
Kear, B.P., 2012, A revision of Australia’s Jurassic plesiosaurs: Palaeontology, v. 55, p. 11251138.
Ketchum, H.F., and Benson, R.B., 2010, Global interrelationships of Plesiosauria (Reptilia, Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses: Biological Reviews, v. 85, p. 361392.
Ketchum, H.F., and Benson, R.B.J., 2011, A new pliosaurid (Sauropterygia, Plesiosauria) from the Oxford Clay Formation (Middle Jurassic, Callovian) of England: evidence for a gracile, longirostrine grade of Early–Middle Jurassic pliosaurids: Special Papers in Palaeontology, v. 86, p. 109129.
Knutsen, E.M., 2012, A taxonomic revision of the genus Pliosaurus (Owen, 1841a) Owen, 1841b: Norwegian Journal of Geology, v. 92, p. 259276.
Knutsen, E.M., Druckenmiller, P.S., and Hurum, J.H., 2012, A new species of Pliosaurus (Sauropterygia: Plesiosauria) from the middle Volgian of central Spitsbergen, Norway: Norwegian Journal of Geology, v. 92, p. 235258.
Leanza, H., Marchese, H., and Riggi, J., 1977, Estratigrafía del Grupo Mendoza con especial referencia a la Formación Vaca Muerta entre los paralelos 35º y 40º L.S., Cuenca Neuquina-Mendocina: Revista de la Asociación Geológica Argentina, v. 32, p. 190208.
Leanza, H.A., 1981, The Jurassic-Cretaceous boundary beds in west-central Argentina and their ammonite zones: Neues Jahrbuch Geologisches Palaeontologisches, v. 161, p. 6292.
Legarreta, L., and Gulisano, C., 1989, Análisis estratigráfico secuencial de la Cuenca Neuquina (Triásico Superior–Terciario Inferior), Argentina, in Chebli, G.A., and Spalletti. L.A., eds., Cuencas Sedimentarias Argentinas, Serie Correlación Geológica 6, p. 221243.
Legarreta, L., and Uliana, M.A., 1991, Jurassic-Cretaceous marine oscillations and geometry of backarc basin fill, central Argentine Andes, in Macdonald, D.I., ed., Sedimentation, Tectonics and Eustasy: Sea level Changes at Active Plate Margins, IAS Special Publication 12, p. 429450.
Lydekker, R., 1889, On the remains and affinities of five genera of Mesozoic reptiles: Quarterly Journal of the Geological Society of London, v. 45, p. 4159.
Maddison, W.P., and Maddison, D.R., 2011, Mesquite R, a package of modules for access to R functions, version 0.7: (accessed 5 August 2017).
Massaferro, J.L., Zeller, M., Giunta, D.L., Sagasti, G., and Eberli, G.P., 2014, Evolución del sistema mixto tithoniano-valanginiano (formaciones Vaca Muerta, Quintuco y equivalentes) a partir de estudios de afloramientos y subsuelo, centro- sur de la Cuenca Neuquina, in Ninth Congreso de Exploración y Desarrollo de Hidrocarburos, Simposio de Recursos No Convencionales, Ampliando el Horizonte Energético, p. 251–274.
Mitchum, R.M., and Uliana, M.A., 1985, Seismic stratigraphy of carbonate depositional sequences, Upper Jurassic–Lower Cretaceous, Neuquén Basin, Argentina, in Bero, B.R., and Woolverton, D.G., eds., Seismic Stratigraphy: an Integrated Approach to Hydrocarbon Exploration, American Association of Petroleum Geologists, Memoir 39, p. 255274.
Noè, L.F., 2001, A taxonomic and functional study of the Callovian (Middle Jurassic) Pliosauroidea (Reptilia, Sauropterygia) [Ph.D. Thesis]: Derby, UK, University of Derby, Volume 1: xxxii + 347 p.; Volume 2: xxxii+182 p.
Noè, L.F., Smith, D.T.J., and Walton, D.I., 2004, A new species of Kimmeridgian pliosaur (Reptilia; Sauropterygia) and its bearings on the nomenclature of Liopleurodon macromerus : Proceedings of the Geologists’ Association, v. 115, p. 1324.
Novozhilov, N., 1948, [Two new pliosaurs from the lower Volga beds Povolzhe (right bank of Volga)]: Doklady Akademii Nauk SSSR, v. 60, p. 115118.
Novozhilov, N., 1964, Order of Sauropterygia: Osnovy Paleontologii, v. 12, p. 309332.
O’Keefe, F.R., 2001, A cladistic analysis and taxonomic revision of the Plesiosauria (Reptilia: Sauropterygia): Acta Zoologica Fennica, v. 213, p. 163.
Otero, R.A., O’Gorman, J.P., Hiller, N., O’Keefe, F.R., and Fordyce, R.E., 2016, Alexandronectes zealandiensis gen. et sp. nov., a new aristonectine plesiosaur from the lower Maastrichtian of New Zealand: Journal of Vertebrate Paleontology, v. 36, e1054494, doi: 10.1080/02724634.2015.1054494.
Owen, R., 1840, Report on British fossil reptiles Part 1: Report of the Ninth Meeting for the British Association for the Advancement of Science (Birmingham), v. 9, p. 43–126.
Owen, R., 1841, Odontography Part 2: London, Hippolyte Bailliere, 655 p.
Owen, R., 1842, Report on British fossil reptiles Part 2: Report of the Eleventh Meeting for the British Association for the Advancement of Science (Plymouth), v. 11, p. 60–204.
Owen, R., 1860, On the orders of fossil and Recent Reptilia, and their distribution in time: Reports of the British Association for the Advancement of Sciences for 1859, v. 29, p. 153166.
Páramo-Fonseca, M.E., Gómez-Pérez, M., Noé, L.F., and Etayo-Serna, F., 2016, Stenorhynchosaurus munozi, gen. et sp. nov. a new pliosaurid from the Upper Barremian (Lower Cretaceous) of Villa de Leiva, Colombia, South America: Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales, v. 40, p. 84103.
Parent, H., Garrido, A.C., Scherzinger, A., Schweigert, G., and Fözy, I., 2015, The Tithonian-lower Valanginian stratigraphy and ammonite fauna of the Vaca Muerta Formation in Pampa Tril, Neuquén Basin, Argentina: Boletín del Instituto de Fisiografía y Geología, v. 86, p. 196.
Phillips, J., 1871, Geology of Oxford and the Valley of the Thames: Oxford, UK, The Clarendon Press, 523 p.
Pol, D., and Escapa, I.H., 2009, Unstable taxa in cladistic analysis: identification and the assessment of relevant characters: Cladistics, v. 25, p. 515527.
Sagasti, G., Remírez, M., and Spalletti, L.A., 2015, Relationships between depositional processes, geochemical signature and seismic geometries in the Vaca Muerta Formation: AAPG Annual Convention and Exhibition 2015, Neuquén Basin, Argentina, Abstracts (CD).
Sassoon, J., Noè, L.F., and Benton, M.J., 2012, Cranial anatomy, taxonomic implications and palaeopathology of an Upper Jurassic pliosaur (Reptilia: Sauropterygia) from Westbury, Wiltshire, UK: Palaeontology, v. 55, p. 743773.
Sato, T., Wu, X.C., Tirabasso, A., and Bloskie, P., 2011, Braincase of a polycotylid plesiosaur (Reptilia: Sauropterygia) from the Upper Cretaceous of Manitoba, Canada: Journal of Vertebrate Paleontology, v. 31, p. 313329.
Sauvage, H.-E., 1873, Notes sur les reptiles fossils: Bulletin de la Société Géologique de France, série 3, v. 1, p. 365386.
Schumacher, B.A., Carpenter, K., and Everhart, M.J., 2013, A new Cretaceous pliosaur (Plesiosauria, Pliosauridae, Brachauchenius eulerti) from the Carlile Shale (middle Turonian) of Russell County, Kansas: Journal of Vertebrate Paleontology, v. 33, p. 613628.
Seeley, H.G., 1869, Index to the Fossil Remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata, Arranged in the Woodwardian Museum of the University of Cambridge: Cambridge, UK, Deighton, Bell, and Company, 143 p.
Seeley, H.G., 1874, Note on some of the generic modifications of the plesiosaurian pectoral arch: Quarterly Journal of the Geological Society of London, v. 30, p. 436449.
Smith, A.S., and Dyke, G.J., 2008, The skull of the giant predatory pliosaur Rhomaleosaurus cramptoni: implications for plesiosaur phylogenetics: Naturwissenschaften, v. 95, p. 975980.
Storrs, G.W., Arkhangelskii, M.S., and Efimov, V.M., 2000, Mesozoic marine reptiles of Russia and other former Soviet republics, in Benton, M., Shishkin, M., Unwin, D., and Kurochkin, E.N., eds., The Age of Dinosaurs in Russia and Mongolia: Cambridge, UK, Cambridge University Press, p. 187210.
Tarlo, L.B., 1960, A review of the Late Jurassic pliosaurs: Bulletin of the British Museum (Natural History), Geology, v. 4, p. 147189.
Weaver, C.E., 1931, Paleontology of the Jurassic and Cretaceous of west central Argentina: University of Washington, Memoir 1, 469 pp.
Wegner, T.H., 1914, Brancasaurus brancai n. g. n. sp., ein Elasmosauride aus dem Wealden Westfalens, in Festschrift für Wilhelm Branca zum 70. Geburtstage 1914, Leipzig, Germany, Borntraeger, p. 235305.
Williston, S. W., 1902, Restoration of Dolichorhynchops osborni, a new Cretaceous plesiosaur: Kansas University Science Bulletin, v. 1, no. 9, p. 241244.
Williston, S.W., 1925, The Osteology of the Reptiles: Cambridge, Massachusetts, Harvard University Press, 300 p.
Yrigoyen, M.R., 1991, Hydrocarbon resources of Argentina: Petrotecnia, Special Issue (13th World Petroleum Congress), Buenos Aires: p. 3854.
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Journal of Paleontology
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