Abstract
Among ancient and modern marine reptiles, several structural types of the locomotor apparatus were or are present, supporting different styles of swimming. Ichthyosaurs, mosasaurs, saltwater crocodiles, and representatives of many other groups swam or swim with horizontal undulations of the body primarily using the tail with a vertical caudal fin. Sea turtles with a reduced tail and their body completely immobilized by the shell use only limbs transformed into flippers for swimming. Sauropterygians had a substantially immobilized trunk and a horizontal caudal fin. They used a unique type of subaquatic locomotion with the leading role of two pairs of powerful flippers and vertical undulations of the tail, partial analogs of which are found in sea turtles, sirens, cetaceans, and some semi-aquatic mammals.
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REFERENCES
Abel, O., Die Eroberungszüge der Wirbelthiere in die Meere der Vorzeit, Jena: Gustav Fischer Verlag, 1924.
Alexander, R., McN., Dynamics of Dinosaurs and Other Extinct Giants, New York: Columbia Univ. Press, 1989.
Buchholtz, E.A., Swimming styles in Jurassic ichthyosaurs, J. Vertebr. Paleontol., 2001, vol. 21, no. 1, pp. 61–73.
Buchholtz, E.A., Booth, A.C., and Webbink, K.E., Vertebral anatomy in the Florida manatee, Trichechus manatus latirostris: a developmental and evolutionary analysis, Anat. Rec., 2007, vol. 290, no. 6, pp. 624–637.
Carpenter, K., Sanders, F., Reed, B., Reed, J., and Larson, P., Plesiosaur swimming as interpreted from skeletal analysis and experimental results, Trans. Kansas Acad. Sci., 2010, vol. 113, nos. 1–2, pp. 1–34.
Carroll, R.L., Plesiosaur ancestors from the Upper Permian of Madagascar, Phil. Trans. R. Soc., London, 1981, vol. 293B, no. 1066. pp. 315–383.
Carroll, R.L. and Gaskill, P., The nothosaur Pachypleurosaurus and the origin of plesiosaurs, Phil. Trans. R. Soc., London, 1985, vol. 309, no. 1139, pp. 315–383.
Cruickshank, A.R.I., Martill, D.M., and Noe, L.F., A pliosaur (Reptilia, Sauropterygia) exhibiting pachyostosis from the Middle Jurassic of England, J. Geol. Soc., London, 1996, vol. 153, pp. 873–879.
Dames, W., Die Plesiosaurier der Süddeutschen Liasformation, Abhandlungen Königliche Preussische Akademie der Wissenschaften fur Berlin (Phys.-Math.), 1895, no. 2, pp. 1–81.
Diedrich, C.G., The oldest “subaquatic flying” reptile in the world—Pistosaurus longaevus Meyer, 1839 (Sauropterygia) from the Middle Triassic of Europe, in The Triassic System, Bull. N. M. Mus. Nat. Hist. Sci., 2013, vol. 61, pp. 169–215.
Fish, F.E., Function of the compressed tail of surface swimming muskrats (Ondatra zibethicus), J. Mammal., 1982, vol. 63, no. 4, pp. 591–597.
Fraas, E., Die Meer-Krocodilier (Thalattosuchia) des oberen Jura unter specieller Berücksichtigung von Dacosaurus und Geosaurus, Palaeontographica, 1902, vol. 49, no. 1, pp. 1–72.
Fraas, E., Plesiosaurier aus dem oberen Lias von Holzmaden, Palaeontographica, 1910, vol. 57, nos. 3–4, pp. 105–140.
Frey, E., Mulder, E.W.A., Stinnesbeck, W., Rivera-Sylva, H.E., Padilla- Gutiérrez, J.M., and González-González, A.H., A new polycotylid plesiosaur with extensive soft tissue preservation from the early Late Cretaceous of northeast Mexico, Boletin de la Sociedad Geologica Mexicana, 2017, vol. 69, no. 1, pp. 87–134.
Gregory, W.K., Evolution Emerging, New York: Macmillan, 1951, vol. 2.
Huene, F., Von, Ein neuer Plesiosaurier aus dem oberen Lias Württembergs, Jahresheft Vereins Vaterlandische Naturkunde Württembergs, 1923¸vol. 79, pp. 1–21.
Ivlev, Yu.F., Kuznetsov, A.N., and Rutovskaya, M.V., Preliminary data on the swimming kinematics of the Russian desman (Desmana moschata L.), Dokl. Biol. Sci., 2010, vol. 431, no. 6, pp. 144–148.
Lamantin. Morfologicheskie adaptatsii (Manatee. Morphological Adaptations), Sokolov, V.E., Ed., Moscow: Nauka, 1986.
Lavrov, L.S., Bobry Paleoarktiki (Beavers of Palearctic), Voronezh: Voronezh. Univ., 1981.
Lindgren, J., Jagt, J.W.M., and Caldwell, M.W., A fishy mosasaur: the axial skeleton of Plotosaurus (Reptilia, Squamata) reassessed, Lethaia, 2007, vol. 40, no. 2, pp. 153–160.
Lindgren, J., Caldwell, M.W., and Jagt, J.W.M., New data on the postcranial anatomy of the California mosasaur Plotosaurus bennisoni (Camp, 1942) (Upper Cretaceous: Maastrichtian), and the taxonomic status of P. tuckeri (Camp, 1942), J. Vertebr. Paleontol., 2008, vol. 28, no. 4, pp. 1043–1054.
Lindgren, J., Caldwell, M.W., Konishi, T., and Chiappe, L.M., Convergent evolution in aquatic tetrapods: insights from an exceptional fossil mosasaur, PLoS One, 2010, vol. 5, no. 8, pp. 1–10. e11998.
Lindgren, J., Kaddumi, H.F., and Polcyn, M.J., Soft tissue preservation in a fossil marine lizard with a bilobed tail fin, Nat. Commun., 2013, vol. 4, no. 2423, pp. 1–8.
Lingham-Soliar, T. and Plodowski, G., Taphonomic evidence for high-speed adapted fins in thunniform ichthyosaurs, Naturwissenschaften, 2007, vol. 94, no. 1, pp. 65–70.
Mazin, J.-M., Mesozoic marine reptiles: an overview, in Secondary Adaptation of Tetrapods to Life in Water, Mazin, J.-M. and de Buffrénil, V., Eds., München: Verlag Dr. Friedrich Pfeil, 2001, pp. 95–117.
McGowan, C., The ichthyosaurian tail: sharks do not provide an appropriate analogue, Palaeontology, 1992, vol. 35, no. 2, pp. 555–570.
McHenry, C.R., Cook, A.G., and Wroe, S., Bottom-feeding plesiosaurs, Science, 2005, vol. 310, no. 5745, p. 75.
Mordvinov, Yu.E., Funktsional’naya morfologiya plavaniya ptits i poluvodnykh mlekopitayushchikh (Functional Morphology of Swimming in Birds and Semi-Aquatic Mammals), Kiev: Naukova Dumka, 1984.
Motani, R., Evolution of fish-shaped reptiles (Reptilia: Ichthyopterygia) in their physical environments and constraints, Annu. Rev. Earth Planet. Sci., 2005, vol. 33, pp. 395–420.
Motani, R., The evolution of marine reptiles, Evol.: Educ. Outreach, 2009, no. 2, pp. 224–235.
O’Keefe, F.R., Street, H.P., Wilhelm, B.C., Richards, C.D., and Zhu, H., A new skeleton of the cryptoclidid plesiosaur Tatenectes laramiensis reveals a novel body shape among plesiosaurs, J. Vertebr. Palaeontol., 2011, vol. 31, no. 2, pp. 330–339.
O’Keefe, F.R., Otero, R.A., Soto-Acuna, S., O’Gorman, J.P.O., Godfrey, S.J., and Chatterjee, S., Cranial anatomy of Morturneira seymourensis from Antarctica, and the evolution of filter feeding in plesiosaurs of the austral late cretaceous, J. Vertebr. Paleontol., 2017, vol. 37, no. 4, pp. 1–13. e1347570.
Otero, R.A., Soto-Acuna, S., Frank, R.O., and Keefe, F.R., Osteology of Aristonectes quiriquinensis (Elasmosauridae, Aristonectinae) from the Upper Maastrichtian of Central Chile, J. Vertebr. Palaeontol., 2018, vol. 38, no. 1, pp. 1–19. e1408638.
Pinna, G. and Nosotti, S., Anatomia, morfologia funzionale e paleoecologia del rettile Placodonte, Pseuphoderma alpinum Meyer, 1858, Memorie della Societa Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano, 1989, vol. 25, no. 2, pp. 17–50.
Renesto, S., A new specimen of Tanystropheus (Reptilia, Protorosauria) from the Middle Triassic of Switzerland and the ecology of the genus, Rivista Italiana di Paleontologia e Stratigrafia, 2005, vol. 111, no. 3, pp. 377–394.
Renesto, S. and Saller, F., Evidences for a semi aquatic life style in the Triassic diapsid reptile Tanystropheus,Rivista Italiana di Paleontologia e Stratigrafia, 2018, vol. 124, no. 1, pp. 23–34.
Renesto, S. and Tintori, A., Functional morphology and mode of life of the Late Triassic placodont Psephoderma alpinum, Meyer from the Calcare di Zorzino (Lombardy, N. Italy), Rivista Italiana di Paleontologia e Stratigrafia, 1995, vol. 101, no. 1, pp. 37–48.
Rieppel, O., Osteology of Simosaurus gaillardoti and the relationships of steam-group Sauropterygia, Fieldiana Geol. N.S, 1994, vol. 28, pp. 1–85.
Robinson, J.A., The locomotion of plesiosaurs, Neues Jahrbuch für Geologie und Palӓontologie, Abhandlungen, 1975, vol. 149, no. 3, pp. 286–332.
Romer, A.S., Osteology of the Reptilia, Chicago: Univ. of Chicago Press, 1956.
Sachs, S., Hornung, J.J., and Kear, B.P., Reappraisal of Europe’s most complete Early Cretaceous plesiosaurian: Brancasaurus brancai Wegner, 1914 from the “Wealden facies” of Germany, PeerJ, 2016, no. 4, pp. 1–79. e2813.
Sander, P.M., Ichthyosauria: their diversity, distribution, and phylogeny, Palӓontologische Zeitschrift, 2000, vol. 74, nos. 1–2, pp. 1–35.
Sennikov, A.G., New data on the herpetofauna of the Early Triassic Donskaya Luka locality, Volgograd region, Paleontol. J., 2015, vol. 49, no. 11, pp. 1161–1173.
Sennikov, A.G., On the structure and locomotor functions of the tail in marine reptiles, in Sovremennye problemy paleontologii. Materialy LXI sessii Paleontologicheskogo obshchestva pri Ross. Akad. Nauk (13–17 aprelya 2015 g., Sankt-Peterburg (Modern Problems of Paleontology: Proc. LXI Session of the Paleontological Society of Ross. Acad. Sci. (April 13–17, 2015, St. Petersburg)), St. Petersburg, 2015a, pp. 169–171.
Sennikov, A.G., Features of subaqueous locomotion of Mesozoic marine reptiles, in Melovaya sistema Rossii i blizhnego zarubezh’ya: problemy stratigrafii i paleogeografii. Sbornik Nauchnykh Trudov (Cretaceous System in Russia and Adjacent Countries: Problems of Stratigraphy and Paleogeography. Collected Scientific Papers), Baraboshkin, E.Yu., Ed., Simferopol: Chernomorpress, 2016, pp. 248–250.
Sennikov, A.G., The peculiarities of the structure and role of the tail in the subaqueous locomotion in Sauropterygia, in Evolyutsionnaya i funktsional’naya morfologiya pozvonochnykh, Materialy Vserossiiskoi konferentsii i shkoly dlya molodykh uchenykh pamyati Feliksa Yanovicha Dzerzhinskogo (The Evolutionary and Functional Morphology of Vertebrates: Proc. All-Russia Conf. and School for Young Scientists in Memory of Felix Yanovich Dzerzhinsky), Moscow: Tov. Nauch. Izd. KMK, 2017, pp. 260–266.
Smith, A.S., Morphology of the caudal vertebrae in Rhomaleosaurus zetlandicus and a review of the evidence for a tail fin in Plesiosauria, Paludicola, 2013, vol. 9, no. 3, pp. 144–158.
Sokolov, V.E., Sistematika mlekopitayushchikh (otryady: odnoprokhodnykh, sumchatykh, nasekomoyadnykh, sherstokrylov, rukokrylykh, primatov, nepolnozubykh, yashcherov) (Systematics of Mammals (Orders Monotremata, Marsupialia, Insectivora, Dermoptera, Chiroptera, Primates, Pilosa, and Manis)), Moscow: Vysshaya Shkola, 1973.
Sokolov, V.E., Sistematika mlekopitayushchikh (kitoobraznye, khishchnye, lastonogie, trubkozubye, khobotnye, damany, sireny, parnokopytnye, mozolenogie, neparnokopytnye) (Systematics of Mammals (Cetacea, Carnivora, Pinnipedia, Tubelidentia, Proboscidea, Hyracoidea, Sirenia, Artiodactyla, Tylopoda, and Perissodactyla)), Moscow: Vysshaya Shkola, 1979.
Storrs, G.W., Anatomy and relationships of Corosaurus alcovensis (Diapsida: Sauropterygia) and the Triassic Alcova Limestone of Wyoming, Bull. Peabody Mus. Nat. Hist., 1991, vol. 44, pp. 1–151.
Storrs, G.W., Function and phylogeny in sauropterygian (Diapsida) evolution, Am. J. Sci., 1993, vol. 293-A, pp. 63–90.
Sukhanov, V.B., Obshchaya sistema simmetrichnoi lokomotsii i osobennosti peredvizheniya nizshikh tetrapod (The General System of Symmetrical Locomotion and Features of Movement of Lower Tetrapods), Leningrad: Nauka, 1968.
Thewissen, J.G.M. and Fish, F.E., Locomotor evolution in the earliest cetaceans: functional model, modern analogues and paleontological evidence, Paleobiology, 1997, vol. 23, no. 4, pp. 482–490.
Wegner, T., Brancasaurus brancai n.g. n.sp., in Elasmosauridae aus dem Wealden Westfalens, Schoendorf, F., Ed., Berlin: Branca-Festschrift, Gebrüda Bornträga, 1914, pp. 235–305.
Wiffen, J., de Buffrénil, V., de Ricqlès, A., and Mazin, J.-M., Ontogenetic evolution of bone structure in Late Cretaceous Plesiosauria from New Zealand, Geobios, 1995, vol. 28, pp. 625–640.
Wilhelm, B.C. and O’Keefe, F.R., A new partial skeleton of a cryptoclidid plesiosaur from the Upper Jurassic Sundance formation of Wyoming, J. Vertebr. Paleontol., 2010, vol. 30, no. 6, pp. 1736–1742.
Williston, S.W., Water Reptiles of the Past and Present, Chicago: Univ. of Chicago Press, 1914.
Wiman, C.J., Some reptiles from the Niobrara group in Kansas, Bull. Geol. Inst. Uppsala, 1920, vol. 18, pp. 9–18.
Young, M.T., Brusatte, S.L., Ruta, M., and Andrade, M.B., The evolution of Metriorhynchoidea (Mesoeucrocodylia: Thalattosuchia): an integrated approach using geometric morphometrics, analysis disparity and biomechanics, Zool. J. Linn. Soc., 2010, vol. 158, no. 4, pp. 801–859.
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This work was supported by state subsidies to Kazan Federal University towards the increase of its competitiveness among the world’s leading scientific and educational centers, as well as by the Russian Foundation for Basic Research (project nos. 17-04-00410, 16-05-00711, and 17-54-10013).
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Sennikov, A.G. Peculiarities of the Structure and Locomotor Function of the Tail in Sauropterygia. Biol Bull Russ Acad Sci 46, 751–762 (2019). https://doi.org/10.1134/S1062359019070100
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DOI: https://doi.org/10.1134/S1062359019070100