DOCSLIB.ORG

Osteology and Phylogeny of Late Jurassic Ichthyosaurs from the Slottsmøya Member Lagerstätte (Spitsbergen, Svalbard)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Osteology and Phylogeny of Late Jurassic Ichthyosaurs from the Slottsmøya Member Lagerstätte (Spitsbergen, Svalbard) Osteology and phylogeny of Late Jurassic ichthyosaurs from the Slottsmøya Member Lagerstätte (Spitsbergen, Svalbard) LENE L. DELSETT, AUBREY J. ROBERTS, PATRICK S. DRUCKENMILLER, and JØRN H. HURUM Delsett, L.L., Roberts, A.J., Druckenmiller, P.S., and Hurum, J.H. 2019. Osteology and phylogeny of Late Jurassic ichthyosaurs from the Slottsmøya Member Lagerstätte (Spitsbergen, Svalbard). Acta Palaeontologica Polonica 64 (4): 717–743. Phylogenetic relationships within the important ichthyosaur family Ophthalmosauridae are not well established, and more specimens and characters, especially from the postcranial skeleton, are needed. Three ophthalmosaurid specimens from the Tithonian (Late Jurassic) of the Slottsmøya Member Lagerstätte on Spitsbergen, Svalbard, are described. Two of the specimens are new and are referred to Keilhauia sp. and Ophthalmosauridae indet. respectively, whereas the third specimen consists of previously undescribed basicranial elements from the holotype of Cryopterygius kristiansenae. The species was recently synonymized with the Russian Undorosaurus gorodischensis, but despite many similarities, we conclude that there are too many differences, for example in the shape of the stapedial head and the proximal head of the humerus; and too little overlap between specimens, to warrant synonymy on species level. A phylogenetic analysis of Ophthalmosauridae is conducted, including all Slottsmøya Member specimens and new characters. The two proposed ophthalmosaurid clades, Ophthalmosaurinae and Platypterygiinae, are retrieved under some circumstances, but with lit- tle support. The synonymy of three taxa from the Slottsmøya Member Lagerstätte with Arthropterygius is not supported by the present evidence. Key words: Ichthyosauria, Ophthalmosauridae, Undorosaurus, Keilhauia, basicranium, phylogenetic analysis, Juras sic, Norway. Lene L. Delsett [[email protected]], Natural History Museum, P.O. Box 1172 Blindern, 0318 Oslo, Norway; Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway. Aubrey J. Roberts [[email protected]], The Natural History Museum, Earth Sciences, Cromwell Road, London SW7 5BD, UK. Patrick S. Druckenmiller [[email protected]], University of Alaska Museum, Fairbanks, Alaska, USA; Depart- ment of Geosciences, University of Alaska Fairbanks, Alaska, USA. Jørn H. Hurum [[email protected]], Natural History Museum, P.O. Box 1172 Blindern, 0318 Oslo, Norway. Received 20 November 2018, accepted 3 June 2019, available online 25 October 2019. Copyright © 2019 L.L. Delsett et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 2016; Fernández and Talevi 2014; Fernández and Campos Introduction 2015; Paparella et al. 2016). However, a consensus of rela- tionships within the family remains elusive. While some Ichthyosaurs were important marine predators of the studies recognize the existence of two major subclades, Meso zoic seas. With one exception (Fischer et al. 2013a), Ophthalmosaurinae and Platypterygiinae (e.g., Fischer et all Late Jurassic–Cretaceous ichthyosaurs belong to Oph- al. 2012, 2016; Roberts et al. 2014; Delsett et al. 2017), thal mo sauridae, a cosmopolitan and speciose clade that others fail to recover this pattern or find only a mono- has been the subject of considerable interest in the past phyletic Platypterygiinae (Maxwell et al. 2015; Paparella decade leading to new insights regarding their evolution et al. 2016; Moon 2017). Understanding ophthalmosaurid at the Jurassic–Cretaceous boundary and extinction in phylogeny is critical for interpreting evolutionary rates the early Late Cretaceous (Fischer et al. 2013a, 2014a, and ecological diversification of the clade (Fischer et al. Acta Palaeontol. Pol. 64 (4): 717–743, 2019 https://doi.org/10.4202/app.00571.2018 718 ACTA PALAEONTOLOGICA POLONICA 64 (4), 2019 B 80° N Louisfjellet 78° N A 12° E 20°28E E ° Fig. 1. A. Map of Svalbard archipelago and the main island Spitsbergen with excavation area marked with an asterisk. B. Geological map of the excavation sites for the SML ophthalmosaurid specimens described and discussed in this paper (red dots); see Fig. 2. Adapted from Hurum et al. (2012). 2013b, 2016). This requires a better morphological under- Motani 2003; Maisch 2010). The Russian specimens are im- standing of new and existing specimens from which new portant to the understanding of palaeobiogeography and phy- and refined cranial and postcranial characters can be based logeny in the Boreal Ocean (Maxwell 2010) and recent pub- (Maxwell et al. 2015). lications have provided valuable information (Fischer et al. The Slottsmøya Member Lagerstätte (SML), Spitsbergen, 2011, 2013b; Zverkov et al. 2015b; Arkhangelsky et al. 2018; Norway, contains a diverse assemblage of marine reptiles, Zverkov and Efimov 2019; Zverkov and Prilepskaya 2019). particularly plesiosaurians and ichthyosaurs, and provides This paper formally describes three specimens from new data on ophthalmosaurids from at or near the Jurassic/ the Tithonian (Late Jurassic) of the Slottsmøya Member Cretaceous boundary (Hurum et al. 2012; Delsett et al. 2016; Lagerstätte. PMO 222.667 is referred to Keilhauia sp., pre- Fernández et al. 2018) (Figs. 1, 2). The SML taxa have some- viously described from the SML and significant for phy- times been recovered in a monophyletic Ophthalmosaurinae logenetic analysis because it preserves a combination of (but see Roberts et al. 2014; Paparella et al. 2016), but many basicranial and pectoral remains. A recent paper assigned more specimens from this locality remain to be described to newly described ophthalmosaurid specimens from localities further test this phylogenetic hypothesis. Many contempora- in Russia to Arthropterygius, and synonymized the SML neous ichthyosaur specimens to the SML assemblage have taxa Palvennia hoybergeti, Keilhauia nui, and Janusaurus been excavated along the Volga River in Russia, which were lundi with the genus (Zverkov and Prilepskaya 2019). These at the time connected by sea (Mutterlose et al. 2003). Due taxonomic conclusions are discussed briefly here, while a to problems with accessibility and inadequately published full evaluation of Arthropterygius in Boreal oceans will be descriptions, many Russian taxa have been reviewed based addressed thoroughly in a follow-up paper. PMO 224.252 only on publications and not on personal inspection, and is a skull referred to Ophthalmosauridae indet. The pa- often synonymized with better known taxa from Western per also describes basicranial elements from the holotype Europe (Maisch and Matzke 2000; McGowan and Motani of Cryopterygius kristiansenae (PMO 214.578), one of the 2003; Maisch 2010) but see Storrs et al. (2000). The only most complete and articulated ophthalmosaurids worldwide exception is Undorosaurus (Efimov 1997, 1999a) which is (Druckenmiller et al. 2012). In 2015, additional mechani- mostly regarded as valid (Storrs et al. 2000; McGowan and cal preparation was performed to prepare the specimen for DELSETT ET AL.—LATE JURASSIC ICHTHYOSAURS FROM SPITSBERGEN 719 display, and the basioccipital, a partial basisphenoid and m two stapes were removed for description. Similarities be- 50 tween the two genera, Undorosaurus and Cryopterygius, have been pointed out repeatedly (Druckenmiller et al. 2012; Arkhangelsky and Zverkov 2014; Delsett et al. 2017, 2018) Keilhauia nui Early and Cryopterygius kristiansenae was recently synonymized PMO 222.655 (holotype) Berriasian with Undorosaurus gorodischensis (Zverkov and Efimov Cretaceous 2019). In this contribution, the new interpretations of the 40 Ophthalmosauridae indet. holotype of Cryopterygius kristiansenae PMO 214.578 by PMO 222.658 Zverkov and Efimov (2019) are discussed in order to eval- uate their hypothesis of synonymy at the species level. A phylogenetic analysis is conducted including all described SML specimens in an expanded matrix using new postcra- nial characters to investigate their phylogenetic position and late 30 discuss interrelationships in Ophthalmosauridae. Institutional abbreviations.—CAMSM, Sedgwick Museum of Earth Sciences, UK; CMN, Canadian Museum of Nature, Canada; GLAHM, The Hunterian Museum, University of Cryopterygius kristiansenae Glasgow, UK; IRSNB, Royal Belgian Institute of Natural 20 PMO 214.578 (holotype) Sciences, Brussels, Belgium; LEICT, New Walk Museum and Ophthalmosauridae indet. Art Gallery, Leicester, UK; LEIUG, University of Lei cester, PMO 224.250 UK; MANCH, Manchester Museum, UK; MLP, Museo de Palvennia hoybergeti Jurassic la Plata, La Plata, Argentina; MOZ, Museo de Paleontología Tithonian PMO 222.669 y Mineralogía Prof. Juan F. Olsacher, Zapala, Argentina; Palvennia hoybergeti NHMUK, Natural History Museum, London, UK; OUMNH, middle 10 SVB 1451 (holotype) Oxford University Museum, UK; PMO, Natural History Museum, paleontological collections, Oslo, Norway; SNHM Ophthalmosauridae indet. Staat liches Naturhistorisches Museum Braunschweig, Ger- PMO 224.252 many; SNSB-BSPG, Bayerische Staats sammlung für Palä- ontologie und Geologie, Munich, Ger many; SGS, SVB, Sval- bard Museum, Longyear, Spits bergen; UPM, Paleonto logical 0 Echinoderm marker bed Museum of Undory, Ul’ya novsk, Russia. Janusaurus lundi Other abbreviations.—CI,
Load more

Recommended publications
  • Resetting the Evolution of Marine Reptiles at the Triassic-Jurassic Boundary
    Resetting the evolution of marine reptiles at the Triassic-Jurassic boundary Philippa M. Thorne, Marcello Ruta, and Michael J. Benton1 School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, United Kingdom Edited by Neil Shubin, University of Chicago, Chicago, IL, and accepted by the Editorial Board March 30, 2011 (received for review December 18, 2010) Ichthyosaurs were important marine predators in the Early Jurassic, life, swimming with lateral undulations of the tail and steering and an abundant and diverse component of Mesozoic marine with elongate fore paddles and producing live young at sea. ecosystems. Despite their ecological importance, however, the After the Tr-J bottleneck, ichthyosaurs apparently did not Early Jurassic species represent a reduced remnant of their former achieve such diversity of form but nonetheless recovered suffi- significance in the Triassic. Ichthyosaurs passed through an evolu- ciently to be the dominant marine predators of the Early Ju- tionary bottleneck at, or close to, the Triassic-Jurassic boundary, rassic, after which they dwindled in diversity through the Middle which reduced their diversity to as few as three or four lineages. and Late Jurassic and much of the Cretaceous until they dis- Diversity bounced back to some extent in the aftermath of the appeared at the end of the Cenomanian, ∼100 Ma, after having end-Triassic mass extinction, but disparity remained at less than had a significant role in Mesozoic seas for 150 Myr. one-tenth of pre-extinction levels, and never recovered. The group In this study, we concentrate on disparity (morphological fi remained at low diversity and disparity for its nal 100 Myr.
    [Show full text]
  • Cryptoclidid Plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert
    Journal of Vertebrate Paleontology ISSN: (Print) (Online) Journal homepage: https://www.tandfonline.com/loi/ujvp20 Cryptoclidid plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert Rodrigo A. Otero , Jhonatan Alarcón-Muñoz , Sergio Soto-Acuña , Jennyfer Rojas , Osvaldo Rojas & Héctor Ortíz To cite this article: Rodrigo A. Otero , Jhonatan Alarcón-Muñoz , Sergio Soto-Acuña , Jennyfer Rojas , Osvaldo Rojas & Héctor Ortíz (2020): Cryptoclidid plesiosaurs (Sauropterygia, Plesiosauria) from the Upper Jurassic of the Atacama Desert, Journal of Vertebrate Paleontology, DOI: 10.1080/02724634.2020.1764573 To link to this article: https://doi.org/10.1080/02724634.2020.1764573 View supplementary material Published online: 17 Jul 2020. Submit your article to this journal Article views: 153 View related articles View Crossmark data Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=ujvp20 Journal of Vertebrate Paleontology e1764573 (14 pages) © by the Society of Vertebrate Paleontology DOI: 10.1080/02724634.2020.1764573 ARTICLE CRYPTOCLIDID PLESIOSAURS (SAUROPTERYGIA, PLESIOSAURIA) FROM THE UPPER JURASSIC OF THE ATACAMA DESERT RODRIGO A. OTERO,*,1,2,3 JHONATAN ALARCÓN-MUÑOZ,1 SERGIO SOTO-ACUÑA,1 JENNYFER ROJAS,3 OSVALDO ROJAS,3 and HÉCTOR ORTÍZ4 1Red Paleontológica Universidad de Chile, Laboratorio de Ontogenia y Filogenia, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Santiago, Chile, [email protected]; 2Consultora Paleosuchus Ltda., Huelén 165, Oficina C, Providencia, Santiago, Chile; 3Museo de Historia Natural y Cultural del Desierto de Atacama. Interior Parque El Loa s/n, Calama, Región de Antofagasta, Chile; 4Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Barrio Universitario, Concepción, Región del Bío Bío, Chile ABSTRACT—This study presents the first plesiosaurs recovered from the Jurassic of the Atacama Desert that are informative at the genus level.
    [Show full text]
  • A Mysterious Giant Ichthyosaur from the Lowermost Jurassic of Wales
    A mysterious giant ichthyosaur from the lowermost Jurassic of Wales JEREMY E. MARTIN, PEGGY VINCENT, GUILLAUME SUAN, TOM SHARPE, PETER HODGES, MATT WILLIAMS, CINDY HOWELLS, and VALENTIN FISCHER Ichthyosaurs rapidly diversified and colonised a wide range vians may challenge our understanding of their evolutionary of ecological niches during the Early and Middle Triassic history. period, but experienced a major decline in diversity near the Here we describe a radius of exceptional size, collected at end of the Triassic. Timing and causes of this demise and the Penarth on the coast of south Wales near Cardiff, UK. This subsequent rapid radiation of the diverse, but less disparate, specimen is comparable in morphology and size to the radius parvipelvian ichthyosaurs are still unknown, notably be- of shastasaurids, and it is likely that it comes from a strati- cause of inadequate sampling in strata of latest Triassic age. graphic horizon considerably younger than the last definite Here, we describe an exceptionally large radius from Lower occurrence of this family, the middle Norian (Motani 2005), Jurassic deposits at Penarth near Cardiff, south Wales (UK) although remains attributable to shastasaurid-like forms from the morphology of which places it within the giant Triassic the Rhaetian of France were mentioned by Bardet et al. (1999) shastasaurids. A tentative total body size estimate, based on and very recently by Fischer et al. (2014). a regression analysis of various complete ichthyosaur skele- Institutional abbreviations.—BRLSI, Bath Royal Literary tons, yields a value of 12–15 m. The specimen is substantially and Scientific Institution, Bath, UK; NHM, Natural History younger than any previously reported last known occur- Museum, London, UK; NMW, National Museum of Wales, rences of shastasaurids and implies a Lazarus range in the Cardiff, UK; SMNS, Staatliches Museum für Naturkunde, lowermost Jurassic for this ichthyosaur morphotype.
    [Show full text]
  • Mannville Group of Saskatchewan
    Saskatchewan Report 223 Industry and Resources Saskatchewan Geological Survey Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan J.E. Christopher 2003 19 48 Printed under the authority of the Minister of Industry and Resources Although the Department of Industry and Resources has exercised all reasonable care in the compilation, interpretation, and production of this report, it is not possible to ensure total accuracy, and all persons who rely on the information contained herein do so at their own risk. The Department of Industry and Resources and the Government of Saskatchewan do not accept liability for any errors, omissions or inaccuracies that may be included in, or derived from, this report. Cover: Clearwater River Valley at Contact Rapids (1.5 km south of latitude 56º45'; latitude 109º30'), Saskatchewan. View towards the north. Scarp of Middle Devonian Methy dolomite at right. Dolomite underlies the Lower Cretaceous McMurray Formation outcrops recessed in the valley walls. Photo by J.E. Christopher. Additional copies of this digital report may be obtained by contacting: Saskatchewan Industry and Resources Publications 2101 Scarth Street, 3rd floor Regina, SK S4P 3V7 (306) 787-2528 FAX: (306) 787-2527 E-mail: [email protected] Recommended Citation: Christopher, J.E. (2003): Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan; Sask. Industry and Resources, Report 223, CD-ROM. Editors: C.F. Gilboy C.T. Harper D.F. Paterson RnD Technical Production: E.H. Nickel M.E. Opseth Production Editor: C.L. Brown Saskatchewan Industry and Resources ii Report 223 Foreword This report, the first on CD to be released by the Petroleum Geology Branch, describes the geology of the Success Formation and the Mannville Group wherever these units are present in Saskatchewan.
    [Show full text]
  • 71St Annual Meeting Society of Vertebrate Paleontology Paris Las Vegas Las Vegas, Nevada, USA November 2 – 5, 2011 SESSION CONCURRENT SESSION CONCURRENT
    ISSN 1937-2809 online Journal of Supplement to the November 2011 Vertebrate Paleontology Vertebrate Society of Vertebrate Paleontology Society of Vertebrate 71st Annual Meeting Paleontology Society of Vertebrate Las Vegas Paris Nevada, USA Las Vegas, November 2 – 5, 2011 Program and Abstracts Society of Vertebrate Paleontology 71st Annual Meeting Program and Abstracts COMMITTEE MEETING ROOM POSTER SESSION/ CONCURRENT CONCURRENT SESSION EXHIBITS SESSION COMMITTEE MEETING ROOMS AUCTION EVENT REGISTRATION, CONCURRENT MERCHANDISE SESSION LOUNGE, EDUCATION & OUTREACH SPEAKER READY COMMITTEE MEETING POSTER SESSION ROOM ROOM SOCIETY OF VERTEBRATE PALEONTOLOGY ABSTRACTS OF PAPERS SEVENTY-FIRST ANNUAL MEETING PARIS LAS VEGAS HOTEL LAS VEGAS, NV, USA NOVEMBER 2–5, 2011 HOST COMMITTEE Stephen Rowland, Co-Chair; Aubrey Bonde, Co-Chair; Joshua Bonde; David Elliott; Lee Hall; Jerry Harris; Andrew Milner; Eric Roberts EXECUTIVE COMMITTEE Philip Currie, President; Blaire Van Valkenburgh, Past President; Catherine Forster, Vice President; Christopher Bell, Secretary; Ted Vlamis, Treasurer; Julia Clarke, Member at Large; Kristina Curry Rogers, Member at Large; Lars Werdelin, Member at Large SYMPOSIUM CONVENORS Roger B.J. Benson, Richard J. Butler, Nadia B. Fröbisch, Hans C.E. Larsson, Mark A. Loewen, Philip D. Mannion, Jim I. Mead, Eric M. Roberts, Scott D. Sampson, Eric D. Scott, Kathleen Springer PROGRAM COMMITTEE Jonathan Bloch, Co-Chair; Anjali Goswami, Co-Chair; Jason Anderson; Paul Barrett; Brian Beatty; Kerin Claeson; Kristina Curry Rogers; Ted Daeschler; David Evans; David Fox; Nadia B. Fröbisch; Christian Kammerer; Johannes Müller; Emily Rayfield; William Sanders; Bruce Shockey; Mary Silcox; Michelle Stocker; Rebecca Terry November 2011—PROGRAM AND ABSTRACTS 1 Members and Friends of the Society of Vertebrate Paleontology, The Host Committee cordially welcomes you to the 71st Annual Meeting of the Society of Vertebrate Paleontology in Las Vegas.
    [Show full text]
  • (Diapsida: Saurosphargidae), with Implications for the Morphological Diversity and Phylogeny of the Group
    Geol. Mag.: page 1 of 21. c Cambridge University Press 2013 1 doi:10.1017/S001675681300023X A new species of Largocephalosaurus (Diapsida: Saurosphargidae), with implications for the morphological diversity and phylogeny of the group ∗ CHUN LI †, DA-YONG JIANG‡, LONG CHENG§, XIAO-CHUN WU†¶ & OLIVIER RIEPPEL ∗ Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, China ‡Department of Geology and Geological Museum, Peking University, Beijing 100871, PR China §Wuhan Institute of Geology and Mineral Resources, Wuhan, 430223, PR China ¶Canadian Museum of Nature, PO Box 3443, STN ‘D’, Ottawa, ON K1P 6P4, Canada Department of Geology, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496, USA (Received 31 July 2012; accepted 25 February 2013) Abstract – Largocephalosaurus polycarpon Cheng et al. 2012a was erected after the study of the skull and some parts of a skeleton and considered to be an eosauropterygian. Here we describe a new species of the genus, Largocephalosaurus qianensis, based on three specimens. The new species provides many anatomical details which were described only briefly or not at all in the type species, and clearly indicates that Largocephalosaurus is a saurosphargid. It differs from the type species mainly in having three premaxillary teeth, a very short retroarticular process, a large pineal foramen, two sacral vertebrae, and elongated small granular osteoderms mixed with some large ones along the lateral most side of the body. With additional information from the new species, we revise the diagnosis and the phylogenetic relationships of Largocephalosaurus and clarify a set of diagnostic features for the Saurosphargidae Li et al.
    [Show full text]
  • Mesozoic Marine Reptile Palaeobiogeography in Response to Drifting Plates
    ÔØ ÅÒÙ×Ö ÔØ Mesozoic marine reptile palaeobiogeography in response to drifting plates N. Bardet, J. Falconnet, V. Fischer, A. Houssaye, S. Jouve, X. Pereda Suberbiola, A. P´erez-Garc´ıa, J.-C. Rage, P. Vincent PII: S1342-937X(14)00183-X DOI: doi: 10.1016/j.gr.2014.05.005 Reference: GR 1267 To appear in: Gondwana Research Received date: 19 November 2013 Revised date: 6 May 2014 Accepted date: 14 May 2014 Please cite this article as: Bardet, N., Falconnet, J., Fischer, V., Houssaye, A., Jouve, S., Pereda Suberbiola, X., P´erez-Garc´ıa, A., Rage, J.-C., Vincent, P., Mesozoic marine reptile palaeobiogeography in response to drifting plates, Gondwana Research (2014), doi: 10.1016/j.gr.2014.05.005 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Mesozoic marine reptile palaeobiogeography in response to drifting plates To Alfred Wegener (1880-1930) Bardet N.a*, Falconnet J. a, Fischer V.b, Houssaye A.c, Jouve S.d, Pereda Suberbiola X.e, Pérez-García A.f, Rage J.-C.a and Vincent P.a,g a Sorbonne Universités CR2P, CNRS-MNHN-UPMC, Département Histoire de la Terre, Muséum National d’Histoire Naturelle, CP 38, 57 rue Cuvier,
    [Show full text]
  • Ichthyosaur Species Valid Taxa Acamptonectes Fischer Et Al., 2012: Acamptonectes Densus Fischer Et Al., 2012, Lower Cretaceous, Eng- Land, Germany
    Ichthyosaur species Valid taxa Acamptonectes Fischer et al., 2012: Acamptonectes densus Fischer et al., 2012, Lower Cretaceous, Eng- land, Germany. Aegirosaurus Bardet and Fernández, 2000: Aegirosaurus leptospondylus (Wagner 1853), Upper Juras- sic–Lower Cretaceous?, Germany, Austria. Arthropterygius Maxwell, 2010: Arthropterygius chrisorum (Russell, 1993), Upper Jurassic, Canada, Ar- gentina?. Athabascasaurus Druckenmiller and Maxwell, 2010: Athabascasaurus bitumineus Druckenmiller and Maxwell, 2010, Lower Cretaceous, Canada. Barracudasauroides Maisch, 2010: Barracudasauroides panxianensis (Jiang et al., 2006), Middle Triassic, China. Besanosaurus Dal Sasso and Pinna, 1996: Besanosaurus leptorhynchus Dal Sasso and Pinna, 1996, Middle Triassic, Italy, Switzerland. Brachypterygius Huene, 1922: Brachypterygius extremus (Boulenger, 1904), Upper Jurassic, Engand; Brachypterygius mordax (McGowan, 1976), Upper Jurassic, England; Brachypterygius pseudoscythius (Efimov, 1998), Upper Jurassic, Russia; Brachypterygius alekseevi (Arkhangelsky, 2001), Upper Jurassic, Russia; Brachypterygius cantabridgiensis (Lydekker, 1888a), Lower Cretaceous, England. Californosaurus Kuhn, 1934: Californosaurus perrini (Merriam, 1902), Upper Triassic USA. Callawayia Maisch and Matzke, 2000: Callawayia neoscapularis (McGowan, 1994), Upper Triassic, Can- ada. Caypullisaurus Fernández, 1997: Caypullisaurus bonapartei Fernández, 1997, Upper Jurassic, Argentina. Chaohusaurus Young and Dong, 1972: Chaohusaurus geishanensis Young and Dong, 1972, Lower Trias- sic, China.
    [Show full text]
  • Palaeoecology and Palaeoenvironments of the Middle Jurassic to Lowermost Cretaceous Agardhfjellet Formation (Bathonian–Ryazanian), Spitsbergen, Svalbard
    NORWEGIAN JOURNAL OF GEOLOGY Vol 99 Nr. 1 https://dx.doi.org/10.17850/njg99-1-02 Palaeoecology and palaeoenvironments of the Middle Jurassic to lowermost Cretaceous Agardhfjellet Formation (Bathonian–Ryazanian), Spitsbergen, Svalbard Maayke J. Koevoets1, Øyvind Hammer1 & Crispin T.S. Little2 1Natural History Museum, University of Oslo, P.O. Box 1172 Blindern, 0318 Oslo, Norway. 2School of Earth and Environment, University of Leeds, Leeds LS2 9JT, United Kingdom. E-mail corresponding author (Maayke J. Koevoets): [email protected] We describe the invertebrate assemblages in the Middle Jurassic to lowermost Cretaceous of the Agardhfjellet Formation present in the DH2 rock-core material of Central Spitsbergen (Svalbard). Previous studies of the Agardhfjellet Formation do not accurately reflect the distribution of invertebrates throughout the unit as they were limited to sampling discontinuous intervals at outcrop. The rock-core material shows the benthic bivalve fauna to reflect dysoxic, but not anoxic environments for the Oxfordian–Lower Kimmeridgian interval with sporadic monospecific assemblages of epifaunal bivalves, and more favourable conditions in the Volgian, with major increases in abundance and diversity of Hartwellia sp. assemblages. Overall, the new information from cores shows that abundance, diversity and stratigraphic continuity of the fossil record in the Upper Jurassic of Spitsbergen are considerably higher than indicated in outcrop studies. The inferred life positions and feeding habits of the benthic fauna refine our understanding of the depositional environments of the Agardhfjellet Formation. The pattern of occurrence of the bivalve genera is correlated with published studies of Arctic localities in East Greenland and northern Siberia and shows similarities in palaeoecology with the former but not the latter.
    [Show full text]
  • Records from the Aalenian–Bajocian of Patagonia (Argentina): an Overview
    Geol. Mag.: page 1 of 11. c Cambridge University Press 2013 1 doi:10.1017/S0016756813000058 Ophthalmosaurian (Ichthyosauria) records from the Aalenian–Bajocian of Patagonia (Argentina): an overview ∗ MARTA S. FERNÁNDEZ † & MARIANELLA TALEVI‡ ∗ División Palaeontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina. CONICET ‡Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, 8332 General Roca, Río Negro, Argentina. CONICET (Received 12 September 2012; accepted 11 January 2013) 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). Keywords: Mollesaurus,‘Stenopterygius grandis’, Middle Jurassic, Neuquén Basin, Argentina. 1. Introduction all Callovian and post-Callovian ichthyosaurs, two different Early Jurassic taxa have been proposed as Ichthyosaurs were one of the main predators in the ophthalmosaurian sister taxa: Stenopterygius (Maisch oceans all over the world during most of the Mesozoic & Matzke, 2000; Sander, 2000; Druckenmiller & (Massare, 1987).
    [Show full text]
  • The Giant Pliosaurid That Wasn't—Revising the Marine Reptiles From
    The giant pliosaurid that wasn’t—revising the marine reptiles from the Kimmeridgian, Upper Jurassic, of Krzyżanowice, Poland DANIEL MADZIA, TOMASZ SZCZYGIELSKI, and ANDRZEJ S. WOLNIEWICZ Madzia, D., Szczygielski, T., and Wolniewicz, A.S. 2021. The giant pliosaurid that wasn’t—revising the marine reptiles from the Kimmeridgian, Upper Jurassic, of Krzyżanowice, Poland. Acta Palaeontologica Polonica 66 (1): 99–129. Marine reptiles from the Upper Jurassic of Central Europe are rare and often fragmentary, which hinders their precise taxonomic identification and their placement in a palaeobiogeographic context. Recent fieldwork in the Kimmeridgian of Krzyżanowice, Poland, a locality known from turtle remains originally discovered in the 1960s, has reportedly provided additional fossils thought to indicate the presence of a more diverse marine reptile assemblage, including giant pliosaurids, plesiosauroids, and thalattosuchians. Based on its taxonomic composition, the marine tetrapod fauna from Krzyżanowice was argued to represent part of the “Matyja-Wierzbowski Line”—a newly proposed palaeobiogeographic belt comprising faunal components transitional between those of the Boreal and Mediterranean marine provinces. Here, we provide a de- tailed re-description of the marine reptile material from Krzyżanowice and reassess its taxonomy. The turtle remains are proposed to represent a “plesiochelyid” thalassochelydian (Craspedochelys? sp.) and the plesiosauroid vertebral centrum likely belongs to a cryptoclidid. However, qualitative assessment and quantitative analysis of the jaws originally referred to the colossal pliosaurid Pliosaurus clearly demonstrate a metriorhynchid thalattosuchian affinity. Furthermore, these me- triorhynchid jaws were likely found at a different, currently indeterminate, locality. A tooth crown previously identified as belonging to the thalattosuchian Machimosaurus is here considered to represent an indeterminate vertebrate.
    [Show full text]
  • General Geology of Lower Cretaceous Heavy Oil
    POOR IMAGE DUE TO ORIGINAL DOCUMENT QUALITY -JC.plt, 5 - ot/-oI General Geology of Lower Cretaceous Heavy • Oil Accumulations In Western Canada By L W. VIGRASS* (Heavy Oil Semillur, The Petrolell1n Society of C.l.~I., Calgary. llIay .5, 1.965) ABSTRACT The oil throughout the belt is asphaltic and contain.'3Downloaded from http://onepetro.org/jcpt/article-pdf/4/04/168/2165766/petsoc-65-04-01.pdf by guest on 01 October 2021 large amounts of sulphur. nitrogen and oxygen. Gra­ Lower Cretaceous sand reservoirs contain about 750 billion barrels of "lscous, heavy oil along a broad arcuate vities range from 6° to 18° API and viscosities from belt that extends from northwestern Alberta into west­ several hundred to several million centipoise at GO°F, central Saskatchewan_ The heavy on is pooled in the Studies of sulphur isotopes, trace metal content and Mannville Group and, in a gross sense. occurs in a marine­ continental transition facies. The accumulation at Peace high molecular weight compounds show a fundamen­ River is in a regional onlap feature. The accumulations in tal similarity between Athabasca, Bonn.yville und the Athabasca-Llo}'dminster region occur across the Lloydminster crude oils. crest and on the southwest flank of a regional anticlinal feature associated with the solution of salt from Middle The change in character of the oil with geographic Devonian beds. These re~ional features had already position and depth is not ' ...·ell documented, but oils formed by the end of Early Cretaceous time. from deeper reservoirs at the south end of the bell Chemical and physical I)rOperties of oils from differ­ are more paraffinic, have higher API gravities and ent accumulations show that they belong to a single oil s:,.,stem and suggest a common mode of origin.
    [Show full text]