Skip to main content
×
×
Home

Ophthalmosaurian (Ichthyosauria) records from the Aalenian–Bajocian of Patagonia (Argentina): an overview

  • MARTA S. FERNÁNDEZ (a1) and MARIANELLA TALEVI (a2)
Abstract

The oldest ophthalmosaurian records worldwide have been recovered from the Aalenian–Bajocian boundary of the Neuquén Basin in Central-West Argentina (Mendoza and Neuquén provinces). Although scarce, they document a poorly known period in the evolutionary history of parvipelvian ichthyosaurs. In this contribution we present updated information on these fossils, including a phylogenetic analysis, and a redescription of ‘Stenopterygius grandis’ Cabrera, 1939. Patagonian ichthyosaur occurrences indicate that during the Bajocian the Neuquén Basin palaeogulf, on the southern margins of the Palaeopacific Ocean, was inhabited by at least three morphologically discrete taxa: the slender Stenopterygius cayi, robust ophthalmosaurian Mollesaurus periallus and another indeterminate ichthyosaurian. Rib bone tissue structure indicates that rib cages of Bajocian ichthyosaurs included forms with dense rib microstructure (Mollesaurus) and forms with an ‘osteoporotic-like’ pattern (Stenopterygius cayi).

Copyright
Corresponding author
Author for correspondence: martafer@fcnym.unlp.edu.ar
References
Hide All
Bardet, N. 1994. Extinction events among Mesozoic marine reptiles. Historical Biology 7, 313–24.
Cabrera, A. 1939. Sobre un Nuevo ictiosaurio del Neuquén. Notas del Museo de La Plata 21, 485–91.
Dal Sasso, C. & Pinna, G. 1996. Besanosaurus leptorhynchus n. gen. n. sp., a new shastasaurid ichthyosaur from the Middle Triassic of Besano (Lombardey, N. Italy). Paleontologia Lombarda 4, 123.
De Blainville, H. M. D. 1835. Description de quelques espèces de reptiles de la Californie. Nouvelles Annales du Muséum d'Histoire Naturelle 4, 233–96.
Druckenmiller, P. S., Hurum, J. H., Knutsen, E. M. & Nakrem, H. A. 2012. Two new ophthalmosaurids (Reptilia: Ichthyosauria) from the Agardhfjellet Formation (Upper Jurassic: Volgian/Tithonian), Svalbard, Norway. Norwegian Journal of Geology 92, 311–39.
Druckenmiller, P. S. & Maxwell, E. E. 2010. A New Lower Cretaceous (Lower Albian) Ichthyosaur Genus from the Clearwater Formation. Canadian Journal of Earth Sciences 1053, 1037–53.
Fernández, A. 1943. La serie Jurásica de la parte central y meridional de la Sierra de Chacai-Co y sus relaciones con los terrenos que la soportan. Ph.D. thesis. Tesis del Museo de La Plata N°6, Universidad Nacional de La Plata, Argentina. Published thesis.
Fernández, M. S. 1994. A new long snouted ichthyosaur from the early Bajocian of Neuquén Basin (Argentina). Ameghiniana 31, 291–7.
Fernández, M. S. 1999. A new ichthyosaur from the Los Molles Formation (Early Bajocian), Neuquén basin, Argentina. Journal of Paleontology 73, 677–81.
Fernández, M. S. 2003. Ophthalmosauria (Ichthyosauria) forefin from the Aalenian-Bajocian boundary of Mendoza province, Argentina. Journal of Vertebrate Paleontology 23, 691–4.
Fernández, M. S. 2007. Ichthyosauria. In Patagonian Mesozoic Reptiles (eds Gasparini, Z., Salgado, L. & Coria, R. A.), pp. 271–91. Indiana University Press.
Fernández, M. S., Archuby, F., Talevi, M. & Ebner, R. 2005. Ichthyosaurian eyes: paleobiological information content in the sclerotic ring of Caypullisaurus (Ichthyosauria, Ophthalmosauria). Journal of Vertebrate Paleontology 25, 330–7.
Fischer, V., Clément, A., Guiomar, M. & Godefroit, P. 2011 a. The first definite record of a Valanginian ichthyosaur and its implications on the evolution of post-Liassic Ichthyosauria. Cretaceous Research 32, 155–63.
Fischer, V., Maisch, M. W., Naish, D., Kosma, R., Liston, J., Joger, U., Krüger, F. J., Pardo Pérez, J., Tainsh, J. & Appleby, R. M. 2012. New ophthalmosaurid ichthyosaurs from the European Lower Cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary. PLoS ONE 7, 123.
Fischer, V., Masure, E., Arkhangelsky, M. S. & Godefroit, P. 2011 b. A new Barremian (Early Cretaceous) ichthyosaur from western Russia. Journal of Vertebrate Paleontology 31, 1010–25.
Gasparini, Z. 1997. A new pliosaur from the Bajocian of the Neuquen Basin, Argentina. Palaeontology 40, 135–47.
Godefroit, P. 1993. The skull of Stenopterygius longifrons (Owen, 1881). Revue de Paléobiologie 7, 6784.
Goloboff, P., Farris, J. & Nixon, K. 2010. T.N.T. 1.1: Tree Analysis Using New Technology. Available at http://www.zmuc.dk/public/phylogeny/TNT/.
Houssaye, A. 2013. Bone histology of aquatic reptiles: what does it tell us about secondary adaptation to an aquatic life? Biological Journal of the Linnean Society 108, 321.
Kear, B. P. 2005. Cranial morphology of Platypterygius longmani Wade, 1990 (Reptilia, Ichthyosauria) from the Lower Cretaceous of Australia. Zoological Journal of the Linnean Society 145, 583622.
Kolb, C., Sánchez-Villagra, M. R. & Scheyer, T. M. 2011. The palaeohistology of the basal ichthyosaur Mixosaurus Baur, 1887 (Ichthyopterygia, Mixosauridae) from the Middle Triassic: palaeobiological implications. Comptes Rendus Palevol 10, 403–11.
Lopuchowycz, V. B. & Massare, J. A. 2002. Bone microstructure of a cretaceous ichthyosaur. Paludicola 3, 139–47.
Maisch, M. W. 2010. Phylogeny, systematics, and origin of the Ichthyosauria – the state of the art. Palaeodiversity 3, 151214.
Maisch, M. W. & Matzke, A. T. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) 298, 1159.
Massare, J. A. 1987. Tooth morphology and prey preference of Mesozoic marine reptiles. Journal of Vertebrate Paleontology 7, 121–37.
Maxwell, E. E. 2010. Generic reassignment of an ichthyosaur from the Queen Elizabeth Islands, Northwest Territories, Canada. Journal of Vertebrate Paleontology 30, 403–15.
Maxwell, E. E., Fernández, M. S. & Schoch, R. 2012. First diagnostic marine reptile remains from the Aalenian (Middle Jurassic): a new ichthyosaur from southwestern Germany. PLOS ONE 7, e41692.
Mazin, J.-M. 1982. Affinités et phylogénie des Ichthyopterygia. Geobios, Mémoire spéciale 6, 8598.
McGowan, C. 1973. The cranial morphology of the Lower Liassic Latipinnate ichthyosaurs of England. Bulletin of the British Museum (Natural History) Geology 24, 1109, 9 pls.
McGowan, C. & Motani, R. 2003. Part 8 Ichthyopterygia. In Handbook of Paleoherpetology (ed. Sues, H. D.). München: Verlag Dr. Friedrich Pfeil.
Motani, R. 1999. Phylogeny of the Ichthyopterygia. Journal of Vertebrate Paleontology 19, 472–95.
Motani, R. 2005. Evolution of fish-shaped reptiles (Reptilia: Ichthyopterygia) in their physical environments and constraints. Annual Review of Earth and Planetary Sciences 33, 395420.
Riccardi, A. C. 2008. El Jurásico de la Argentina y sus ammonites. Revista de la Asociación Geológica Argentina 63, 625–43.
Sander, P. M. 2000. Ichthyosauria: their diversity, distribution, and phylogeny. Paläontologische Zeitschrift 74, 135.
Spalletti, L. A., Gasparini, Z. & Fernández, M. 1994. Facies, ambientes y reptiles marinos de la transición entre las formaciones Los Molles y Lajas (Jurásico Medio), Cuenca Neuquina, Argentina. Acta Geologica Leopoldensia 39, 329–44.
Talevi, M. & Fernández, M. S. 2012. Unexpected skeletal histology of an ichthyosaur from the Middle Jurassic of Patagonia: implications for evolution of bone microstructure among secondary aquatic tetrapods. Naturwissenschaften 99, 241–4.
Talevi, M., Fernández, M. S. & Salgado, L. 2012. Variación ontogenética en la histología ósea de Caypullisaurusbonapartei Fernández, 1997 (Ichthyosauria: Ophthalmosauridae). Ameghiniana 49, 3846.
Thorne, P. M., Ruta, M. & Benton, M. J. 2011. Resetting the evolution of marine reptiles at the Triassic-Jurassic boundary. Proceedings of the National Academy of Sciences of America 108, 8339–44.
Westermann, G. E. G. & Riccardi, A. C. 1979. Middle Jurassic ammonoid fauna and biochronology of the Argentine-Chilean Andes. Part II: Bajocian Stephanocerataceae. Palaeontographica A 164, 85188.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Geological Magazine
  • ISSN: 0016-7568
  • EISSN: 1469-5081
  • URL: /core/journals/geological-magazine
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed