DOCSLIB.ORG

Ordovician Cephalopod Biofacies of South China and Its Provincialization

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ordovician Cephalopod Biofacies of South China and Its Provincialization J ournal of China University o f Geosciences , Vol. 17 , No. 3 , p. 221 - 230 , September 2006 ISS N 1002 - 0705 Printed in China Ordovician Cephalopod Biofacies of South China and Its Provincialization Xiao Chuantao*(肖传桃) Faculty o f Earth Sciences , China University o f Geosciences , Wuhan 430074 , China ; Geosciences College , Y angtze University , J ingz hou 434023 , China Chen Zhiyong (陈志勇) Faculty o f Earth Sciences , China University o f Geosciences , Wuhan 430074 , China ; Qinghai Oil f ield Com pany , Dunhuang 736202 , China Liu Li (刘莉) He Youbin (何幼斌) Geosciences College , Y angtze University , J ingz hou 434023 , China ABSTRACT :The research on biofacies and its provincialization is of important significance not only for the increasing of precision of stratigraphic subdivision and correlation in South China, the reconstruction of ancient environment and paleogeography and even the guiding of oil and gas exploration, but also for the study of paleobiogeogrphy and sea level changes of southern China in Ordovician. On the basis of the studies of the ecological characteristics of Ordovician cephalopods from South China , eighteen cephalopod biofacies are recognized and described :(1)Open platform Proterocameroceras biofacies ;(2) Restricted platform Pseudoectenolites-Xiadongoceras biofacies; ( 3 ) Open platform Retroclitendoceras- Pararetroclitendoceras biofacies;(4)Open platform Prona jaceras-Mamagouceras biofacies;(5) Shelf slope-basin Cyclostomiceras biofacies;(6) Open platform Cameroceras-Cyrtovaginoceras biofacies ; (7) Open platform Coreanoceras-Manchuroceras biofacies;(8) Shelf slope-basin Kaipingoceras- K yminoceras biofacies;(9) Inner shelf Bathmoceras-Protoc ycloceras biofacies;(10) Middle shelf Dideroceras-Ancistroceras biofacies;(11) Deep-water shelf Lituites-Cyclolituites biofacies;(12) Stag- nant basin Lituites-Trilacinoceras biofacies;(13) Deep-water basin Paraendoceras-Sactorthoceras bio- facies;(14) Deep-water shelf Sinoceras-Michelinoceras-Disoceras biofacies;(15) Deep-water shelf Be loitoceras-Jiangshanoceras biofacies;(16) Deep-water shel-f basin Eurasiaticoceras biofacies ;(17) Shelf-slope Jiangxiceras-Yushanoceras biofacies;(18) Deep-water basin Michelinoceras biofacies. The cephalopods of these biofacies, their ecological characteristics, and living conditions are elucidated in this article. The association law of cephalopod biofacies in time and space shows that there were three cepha- lopod biofacies provinces in South China during the Ordovician, i. e. , Yangtze biofacies province , East Guizhou (贵州)-West Hunan (湖南) biofacies province (mixed-type biofacies province), and Central Hunan-West Zhejiang(浙江) biofacies province. It is suggested that differentiation of cephalopod biofa- cies was mainly controlled by sea level changes and tectonic evolution. The differentiation is obvious dur- ing lower sea level and not developed during high sea level. KEY WORDS:cephalopod biofacies, cephalopod biofacies province , sea level changes, Ordovician , South China. INTRODUCTION Bio facies refers to an association of org anism- This paper is suppo rted by the National Natural Science Foundation of eco logy and sedim entary characteristics , w hich can C hina (No. 40272060). reflect a specific ancient environment. Research o n *C orresp on ding author :ctxiao188 @yahoo. com. cn biofacies and its provincialization is significant no t o nly for increasing the precisio n of stratigraphic sub- M anu scrip t received March 10 , 2006. M anu scrip t accepted June 25 , 2006. divisio n and co rrelation , reconstructing ancient envi- 222 Xiao Chuantao , Chen Z hiyo ng , Liu L i and He Yo ubin ronments and paleo geog raphy , and oil and gas ex plo- ance to fo rw ard mov em ent , and a small siphuncle and ration , but also fo r the study of interco ntinental pa- large chambe r are favorable to reg ulate the fluids leobiogeog raphy and sea level chang es. w ithin them . In contrast , cephalo pods w ith a hig h Altho ug h the term biofacies w as established expansion rate , large siphuncle , and sediments w ith- mo re than 30 y ears ago by Bouco t (1981) and Schafer in chambers are po or sw immers and suitable for a (1972), detailed studies have only beg un to em erge shallo w-w ater enviro nment (Fig. 1). in the last few years. There is little research on the paleoecolo gy o f O rdovician cephalopo ds (Zhou , CEPHALOPODS BIOFACIES 2000 ;Xiao and Pan , 1997 ;Xu and Xu , 1986 ). Open Platform Proterocameroceras Biofacies Therefo re , m ore studies on biofacies a re required. It is mainly found in the Xinchang S tage (China This ar ticle presents new research concerning the O r- Stratig raphic Group , 2002) in the Upper Yang tze dovician cephalopo d biofacies o f southern China. area , this biofacies is low in diversity , dominated by O n the basis of the studies on the paleoecological P roterocameroceras and associated with Camero- characteristics o f Ordovician cephalopods from parts ceras, Dayongoceras , and Ellesmeroceras. Cephalo- of South China and the systematic co llectio n and pods of this biofacies a re characterized by a medium- analysis of O rdovician cephalo pods fro m m ore than sized shell , hig h expansion ra te and large siphuncle , ten provinces o f So uth China (Xiao and Pan , 1997 ; therefore , they are no t able to sw im rapidly . Addi- Bureau of Geolog y and M ine ral Resources of H unan tionally , they are mo stly preserved in bioclastic lime- Pro vince , 1997 ;Bureau o f Geo logy and Mineral Re- stone and intraclastic limestone , indicativ e of an sources o f Zhejiang Province , 1997 ;Bureau of Geolo- open-platform enviro nment. g y and Mineral Resources of Jiangxi Province , 1997 ; Bureau of Geolog y and M ineral Resources of Guizhou Restricted Platform Pseudoectenolites-Xiadongoceras Pro vince , 1997 ;Committee o f Chinese Stra tig raphic Biofacies Dictionary , 1996 ;Wang et al. , 1987), the authors This biofacies occurs mainly at the low er par t of have presented the paleoeco logical characteristics the Xinchang Stage (Xiling xia Form ation ) in the pro vided by the da ta and their relationships with sed- Yichang , Songzi , and Tong shan areas of H ubei imentary facies. As a result , 18 cephalopod biofacies Province. It has a high dive rsity of elements do mina- and three cephalopo d biofacies provinces have been ted by Pseudoectenolites and characterized by X ia- recog nized. dongoceras. The co mpo nent members include Changjiangoceras , Dakeoceras , Paraeburoceras , ECOLOGY OF CEPHALOPODS Neoeburoceras, Zhangnanoceras , Anguloceras , Cephalopods are m arine zoo phagous inverte- Clarkoceras , P araconoceras , E llesmeroceroides , and brates , mo st of w hich are nekto nic , w ith so me P arahuaiheceras apart fro m Pseudoectenolites and plankto nic and benthonic org anism s. The lifesty le of X iadongoceras. T hey hav e comm on characteristics , cephalopods depends largely on their shapes and namely , a small-to-medium shell , high expansio n structures. Of the planospiral cephalopods , tho se rate , and a siphuncle lo cated near to the par abdomi- with tig ht spiral , sharp abdo minalis , flattened and nalis , w hich indicates that cephalopods of this bio fa- streamlined shell , sm ooth shell , and complicated su- cies are unable to get used to rapid sw im ming . In ad- ture m ostly adjust to rapid sw imming in deep-w ate r. dition , they are m ostly preserved in dolo rudite. A s a In co ntrast , cephalopods with loose spiral , ventri- result , this biofacies represents a restricted shallow- cous shell , w ell-developed o rnamentation , and simple w ate r enviro nment. suture are unable to become accusto med to rapid sw imming and deep-w ater life , therefore , mo st of Open Platform Retyoclitendoceras-Pararetroclitendo- them are benthonic or saltant sw im in shallow-w ate r. ceras Biofacies H ow ev er , or thomo rphic cephalopo ds are situated dif- This bio facies is mo stly distributed in the m iddle ferently. Cephalopo ds w ith a lo ng shell , low ex pan- part of the Xinchang S tage (N anjing guan Fo rm ation) sion rate , small siphuncle , and no sediments w ithin in East Sichuan , Yichang , Songzi , and Tong shan ar- chambe rs are g ood swim mers and suit a deep-w ater eas of H ubei Province. It is com posed of Retrocliten- enviro nment , because low expansio n rate and no sed- doceras , Pararetroclitendoceras, Sanxiaoceras , Pro- iments in chambers are favo rable fo r reducing resist- terocameroceras , and Escharendoceras. M ost of the O rdo vician Cephalo pod Bio facies o f South China and Its P rov incializa tion 223 genera are w idespread and found in many lo calities a- expansion rate , w hich show s that the cephalopods o f round the w orld. The cephalopods of this biofacies this biofacies are able to become accustomed to mo re are characte rized by a dorsiventrally co mpressed si- rapid sw im ming . M oreover , they are mo stly phuncle and abdominal , curved do rsal part , and low preserved in thick calcsparite intraclastic limesto ne. Figure 1. Environmental distribution of important Ordovician cephalopods in South China. 224 Xiao Chuantao , Chen Z hiyo ng , Liu L i and He Yo ubin Therefo re , this biofacies is indicative of fo rd environ- features indicate that cephalopo ds of this biofacies are m ent , open platfo rm , favo rable to reserving oil and suitable for shallow w ate r and bentho nic sw imming gas. and represent an open platform environment. Open Platform Pronajaceras-Mamagouceras Biofacies Open Platform Coreanoceras-Manchuroceras Biofacies Developed chiefly in the upper par t of the Xin- This bio facies is m ainly distributed in the chang S tage (Fenxiang Formation) in the Middle Daobaow an Stag e of East Sichuan , Yichang and Yang tze a rea such as East Sichuan and the Yichang , Tongshan areas o f H ubei , and the Lo we r Yang tze S ong zi , and To ng shan areas of H ubei Province , this district.
Load more

Recommended publications
  • Part I. Revision of Buttsoceras. Part II. Notes on the Michelinoceratida
    MEMOIR 10 PART I Revision of Buttsoceras PART II Notes on the Michelinoceratida By ROUSSEAU H. FLOWER 1 9 6 2 STATE BUREAU OF MINES AND MINERAL RESOURCES NEW MEXICO INSTITUTE OF MINING AND TECHNOLOGY CAMPUS STATION SOCORRO, NEW MEXICO NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY E. J. Workman, President STATE BUREAU OF MINES AND MINERAL RESOURCES Alvin J. Thompson, Director THE REGENTS MEMBERS Ex OFFICIO The Honorable Edwin L. Mechem ........................................ Governor of New Mexico Tom Wiley .......................................................... Superintendent of Public Instruction APPOINTED MEMBERS William G. Abbott ............................................................................................... Hobbs Holm 0. Bursum, Jr. ......................................................................................... Socorro Thomas M. Cramer ......................................................................................... Carlsbad Frank C. DiLuzio ...................................................................................... Albuquerque Eva M. Larrazolo (Mrs. Paul F.) ............................................................... Albuquerque Published October I2, 1962 For Sale by the New Mexico Bureau of Mines & Mineral Resources Campus Station, Socorro, N. Mex.—Price $2.00 Contents PART I REVISION OF BUTTSOCERAS Page ABSTRACT ....................................................................................................................... INTRODUCTION .............................................................................................................................
    [Show full text]
  • The Carboniferous Evolution of Nova Scotia
    Downloaded from http://sp.lyellcollection.org/ by guest on September 27, 2021 The Carboniferous evolution of Nova Scotia J. H. CALDER Nova Scotia Department of Natural Resources, PO Box 698, Halifax, Nova Scotia, Canada B3J 2T9 Abstract: Nova Scotia during the Carboniferous lay at the heart of palaeoequatorial Euramerica in a broadly intermontane palaeoequatorial setting, the Maritimes-West-European province; to the west rose the orographic barrier imposed by the Appalachian Mountains, and to the south and east the Mauritanide-Hercynide belt. The geological affinity of Nova Scotia to Europe, reflected in elements of the Carboniferous flora and fauna, was mirrored in the evolution of geological thought even before the epochal visits of Sir Charles Lyell. The Maritimes Basin of eastern Canada, born of the Acadian-Caledonian orogeny that witnessed the suture of Iapetus in the Devonian, and shaped thereafter by the inexorable closing of Gondwana and Laurasia, comprises a near complete stratal sequence as great as 12 km thick which spans the Middle Devonian to the Lower Permian. Across the southern Maritimes Basin, in northern Nova Scotia, deep depocentres developed en echelon adjacent to a transform platelet boundary between terranes of Avalon and Gondwanan affinity. The subsequent history of the basins can be summarized as distension and rifting attended by bimodal volcanism waning through the Dinantian, with marked transpression in the Namurian and subsequent persistence of transcurrent movement linking Variscan deformation with Mauritainide-Appalachian convergence and Alleghenian thrusting. This Mid- Carboniferous event is pivotal in the Carboniferous evolution of Nova Scotia. Rapid subsidence adjacent to transcurrent faults in the early Westphalian was succeeded by thermal sag in the later Westphalian and ultimately by basin inversion and unroofing after the early Permian as equatorial Pangaea finally assembled and subsequently rifted again in the Triassic.
    [Show full text]
  • Orthoceras Limestone" of Southwestern Sardinia (Middle-Upper Silurian) ( * )
    Mem. Soc. Geol. /t., 20 (1979), 405-423. 9 ff., 4 tabb. PALEOECOLOGICAL REMARKS ON TUE "ORTHOCERAS LIMESTONE" OF SOUTHWESTERN SARDINIA (MIDDLE-UPPER SILURIAN) ( * ) Memoria di MAURIZIO GNOLI (**), GrAN CLEMENTE PAREA (***). FRANCO Russo(**) & ENRICO SERPAGLI (**) (presentata a Siena, nella Seduta /ematica del /8-/9 maggio 1979) CO NTE NT ricco di fauna esclusivamente pelagica nelle parti p age superiori e decisamente tossico verso il fondo. lNTRODUCTION 405 Analisi statistiche ed esperimenti di laborato­ l"Ìo hanno portato gli scriventi a considerare il GEOLOGICAL REMARKS 406 particolare tipo di orientamento presentato dai SEDIMENTOLOGICAL REMARKS 407 fossili come un effetto del moto ondoso. I gusci ed i loro frammenti, sparsi su un fondo di fango Geometry of the "Orthoceras lenses" 407 fine, verrebbero disposti dalle onde a bande suc­ The problem of Nautiloid orientation 410 cessive che rappresenterebbero l'equivalente mec­ Laboratory experiments 411 canico delle increspature di fondo tipiche dei fon­ Orientation analysis of the orthoconic di sabbiosi. Potrebbe trattarsi di un mare epicontinentale nautiloids 413 di profondità limitata tale da permettere al moto GENERAL FEATURES OF THE FAUNA 417 ondoso di agire sul fondo. Nektic organisms associated with the grap- tolites 417 Organisms possibly attached to floating ABSTRACT plants 417 A study of the fauna and of the sedimento­ ENVIRONMENTAL CONCLUSIONS 420 logica! characteristics of the "Orthoceras limestone" REFERENCES 422 has shown that these sediments were deposited in a normally oxygenated sea rich in an exclusively pelagic fauna in the upper parts but definitely KEY WORDS : Shelf environment, death as­ toxic towards the bottom. semblage, sedimentary structures, depth Statistica! analyses along with laboratory ex­ periments have led.
    [Show full text]
  • Middle Devonian)
    F-l Paleontological Problems of the Hamilton Group (Middle Devonian) H.B. Rollins, N. Eldridge, R.M. Linsley The stratigraphy of the Hamilton Group of the'Middle Devonian of New York State was most recently treated in its entirety by Cooper (1930, 1957). The Hamilton Group of the Chenango Valley (see chart 1) consists primarily of fine clastic sediments and occupies a mid position in this wedge shaped body of rock. In the east the wedge is thickest (about 1,680' in Schoharie Valley (Gruban, 1903, p. 213) and it thins to 285' at Lake Erie in the west (Cooper, 1930, p. 121). In the Chenango Valley the Hamilton Group is 1, 465' thick (op. cit. p. 121) and has a dip to the southwest of 65-75 feet per mile (op. cit. p. 119). The Hamilton Group lies unconformably on the Onondaga Limestone and is overlain unconformably by the Tully Formation. In a very crude sense the Hamilton Group of the Chenango Valley is composed of fine-grained black shales and limestones at the base (the Marcellus Formation) and more clastic units in the upper portion (Skaneateles, Ludlowville and Moscow Formations). However within each of these formations there exists considerable variation from true mud shales through siltstones and up to fine-grained sandstones. The nature of the substrate obviously had a great effect on the faunas associated with them. The black shales are typically associated with a Leiorhynchus fauna, gray shales and siltstones with a Tropidoleptus fauna and the fine-grained sandstones are dominated by bivalves. A more detailed discussion of some of these problems will follow in sections relating to each of the three stops of this trip.
    [Show full text]
  • Review of the Ordovician Stratigraphy and Fauna of the Anarak Region in Central Iran
    See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/286025445 Review of the Ordovician stratigraphy and fauna of the Anarak Region in Central Iran ARTICLE in ACTA GEOLOGICA POLONICA · JANUARY 2015 Impact Factor: 0.84 · DOI: 10.1515/apg-2015-0022 READS 26 6 AUTHORS, INCLUDING: Leonid E. Popov Vachik Hairapetian National Museum Wales Islamic Azad University Khorasgan (Isfahan) Branch 231 PUBLICATIONS 2,239 CITATIONS 33 PUBLICATIONS 130 CITATIONS SEE PROFILE SEE PROFILE Mansoureh Ghobadi Pour Lars E Holmer Golestan University Uppsala University 69 PUBLICATIONS 365 CITATIONS 211 PUBLICATIONS 2,319 CITATIONS SEE PROFILE SEE PROFILE Available from: Leonid E. Popov Retrieved on: 11 December 2015 Acta Geologica Polonica, Vol. 65 (2015), No. 4, pp. 403–435 DOI: 10.1515/agp-2015-0022 Review of the Ordovician stratigraphy and fauna of the Anarak Region in Central Iran LEONID E. POPOV1, VACHIK HAIRAPETIAN2, DAVID H. EVANS3, MANSOUREH GHOBADI POUR4, LARS E. HOLMER5 and CHRISTIAN BAARS1 1Department of Geology, National Museum of Wales, Cardiff CF10 3NP, Wales, United Kingdom. E-mail: [email protected], [email protected] 2Department of Geology, Isfahan (Khorasgan) Branch, Islamic Azad University, PO Box 81595−158, Isfahan, Iran. E-mail: [email protected] 3Natural England, Suite D, Unex House, Bourges Boulevard, Peterborough PE1 1NG, England, United Kingdom. E-mail: [email protected] 4Department of Geology, Faculty of Sciences, Golestan University, Gorgan, Iran. E-mail: [email protected] 5Institute of Earth Sciences, Palaeobiology, Uppsala University, SE-752 36 Uppsala, Sweden. E-mail: [email protected] ABSTRACT: Popov, L.E., Hairapetian, V., Evans, D.H., Ghobadi Pour, M., Holmer, L.E.
    [Show full text]
  • Cephalopod Faunas from Southwestern United States
    ABOUT THE SKETCH ON COVE R- A simple orthocone with gas in the camerae would have an anterior center of gravity (G1) and an apical center of buoyancy (B1). Such a situation would cause the shell to occupy a vertical position, forcing the head into the mud on the sea floor—making the animal very unhappy and uncomfortable, as can be plainly seen from its expression. Weighting the apex of the shell with cameral deposits or siphonal deposits, or both (only cameral deposits are shown here), would move the center of gravity backward, from 01 to G2, and move the center of buoyancy forward, from B1 to B2, permitting the animal to swim and move in a horizontal position—making it very happy and comfortable, as can be seen from the ecstatic expression. Further growth of the shell requires further growth of the deposits, moving the center of gravity forward to midlength (from G2 to G3) and moving the center of buoyancy forward also from B2 to B3. Such an adjustment requires careful physiological skill. If the animal now has a rather smug expression, who can blame it? As indicated elsewhere (Flower, 1955, fig. 1, p. 247), balance is attained completely by siphonal filling in the Endoceratida, by a combination of siphonal and cameral deposits in the Actinoceratida, and mainly by cameral deposits in the Michelinoceratida. However, Hook and Flower (1976) subsequently found that the Michelinoceratidae and Troedssonellidae probably spring from different parts of the Baltoceratidae, in which there are both cameral and siphonal deposits (rods, linings, and annuli in varying combinations) in a siphuncle close to the venter.
    [Show full text]
  • Anatomy and Evolution of the First Coleoidea in the Carboniferous
    Zurich Open Repository and Archive University of Zurich Main Library Strickhofstrasse 39 CH-8057 Zurich www.zora.uzh.ch Year: 2019 Anatomy and evolution of the first Coleoidea in the Carboniferous Klug, Christian ; Landman, Neil H ; Fuchs, Dirk ; Mapes, Royal H ; Pohle, Alexander ; Guériau, Pierre ; Reguer, Solenn ; Hoffmann, René Abstract: Coleoidea (squids and octopuses) comprise all crown group cephalopods except the Nautilida. Coleoids are characterized by internal shell (endocochleate), ink sac and arm hooks, while nautilids lack an ink sac, arm hooks, suckers, and have an external conch (ectocochleate). Differentiating between straight conical conchs (orthocones) of Palaeozoic Coleoidea and other ectocochleates is only possible when rostrum (shell covering the chambered phragmocone) and body chamber are preserved. Here, we provide information on how this internalization might have evolved. We re-examined one of the oldest coleoids, Gordoniconus beargulchensis from the Early Carboniferous of the Bear Gulch Fossil- Lagerstätte (Montana) by synchrotron, various lights and Reflectance Transformation Imaging (RTI). This revealed previously unappreciated anatomical details, on which we base evolutionary scenarios of how the internalization and other evolutionary steps in early coleoid evolution proceeded. We suggest that conch internalization happened rather suddenly including early growth stages while the ink sac evolved slightly later. DOI: https://doi.org/10.1038/s42003-019-0523-2 Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-172717 Journal Article Published Version The following work is licensed under a Creative Commons: Attribution 4.0 International (CC BY 4.0) License. Originally published at: Klug, Christian; Landman, Neil H; Fuchs, Dirk; Mapes, Royal H; Pohle, Alexander; Guériau, Pierre; Reguer, Solenn; Hoffmann, René (2019).
    [Show full text]
  • Revision of Annulated Orthoceridan Cephalopods of the Baltoscandic Ordovician
    Fossil Record 9(1) (2006), 137–163 / DOI 10.1002/mmng.200600005 Revision of annulated orthoceridan cephalopods of the Baltoscandic Ordovician Bjo¨ rn Kro¨ ger*,1& Mare Isakar**,2 1 Bjo¨ rn Kro¨ ger, Museum fu¨ r Naturkunde der Humboldt-Universita¨t, Invalidenstraße 43, D-10115 Berlin, Germany 2 Mare Isakar, University of Tartu, Tartu likool, Geoloogiamuuseum, Vanemuise 46, EST-51014 Tartu, Estonia Received 31 January 2005, accepted 30 September 2005 Published online 01. 02. 2006 With 12 figures Keywords: Cephalopoda, Orthocerida, Middle Ordovician, Late Ordovician, Estonia. Abstract The annulated orthoceridans of the Middle and Late Ordovician of Baltoscandia are described and their systematic frame is revised. The revision of these nautiloids, which are part of the Orthocerida and Pseudorthocerida, is based on the investiga- tion of characters of the septal neck, the siphuncular tube, and the apex. An unequivocal terminology of these characters is suggested and applied. The shape of the septal neck and the siphuncular tube are described for the first time in Palaeodawso- noceras n. gen., Striatocycloceras n. gen., Dawsonoceras fenestratum Eichwald, 1860, and Gorbyoceras textumaraneum (Roe- mer, 1861). Ctenoceras sweeti n. sp. is erected. The apex of Dawsonoceras barrandei Horny´, 1956 is figured and described for the first time. The distribution of the character states of the apex and the septal neck support the emendation of the families Orthoceratidae, Dawsonoceratidae, and Proteoceratidae. The analysis shows also that the families Kionoceratidae, and Leuro- ceratidae must be refused because they represent not natural groups. However, it is also shown that the present knowledge is not sufficient to establish an unequivocal classification of the Middle, and Late Ordovician annulate cephalopods.
    [Show full text]
  • Nautiloid and Bactritoid Cephalopods from the Carboniferous of the Jebel Qamar South Area, United Arab Emirates
    Paleontological Research, vol. 1, no. 3, pp. 157-165,5 Figs., September 30, 1997 © by the Palaeontological Society of Japan Nautiloid and bactritoid cephalopods from the Carboniferous of the Jebel Qamar South area, United Arab Emirates SHWI NIK01, ALAIN PILLEVUIT2 and GERARD STAMPFLP IDepartment of Environmental Studies, Faculty of Integrated Arts and Sciences, Hiroshima University, Higashihiroshima, 739 Japan 21nstitute of Geophysics, University of Paris VII, 75251 Paris Cedex 05, France 31nstitute of Geology and Paleontology, University of Lausanne, BFSH 2, 1015 Lausanne-Dorigny, Switzerland Received 1 November 1996; Revised manuscript accepted 5 August 1997 Abstract. Nine species of cephalopods from the Ayim Formation of the Jebel Qamar South area, United Arab Emirates are described. They include orthoceratids: Michelinoceras sp. 1, Michelinoceras? sp. 2, Temperoceras ayimense sp. nov., Mooreoceras? sp. 1, Mooreoceras? sp. 2, Mitorthoceras? sp., Spyroceratinae, genus and species indeterminate; oncocerid: Poterioceratidae, genus and species in­ determinate; and bactritid: Bactrites cf. quadrilineatus Girty. Based on the fauna, the Early Carbonifer­ ous age of the formation is first established herein. Key words: Ayim Formation, Bactritida, Early Carboniferous, Oncocerida, Orthocerida, United Arab Emirates Introduction shale located in the lower part of the Ayim Formation (Figure 2). Besides cephalopods, the fossils include serpulids (Spir­ The cephalopods described herein were collected from orbis sp.), bryozoans, ostracodes, echinoderms, fish remains the Ayim Formation of previously uncertain age, during field (Robertson et al., 1990), and trace fossils (Pillevuit, 1993). An work in the Jebel Qamar South area, United Arab Emirates age between Ordovician and Early Permian for the Ayim (Figure 1). Although preservation of the material is poor, we Formation is not questionable because of its stratigraphic can provide new knowledge concerning age determination setting, viz.
    [Show full text]
  • Aeontological Studies on the Cephalopods and Trilobites from the Locality･
    New Observations of Shiroishi-ohsawa, Mt. Yokokura, Kochi ＰＩ!efecturewith Ｐａ!aeontological Studies on the Cephalopods and Trilobites from the Locality･ Teiichi Ｋ OBAYASHI ＊ and Jiro Ｋ,ＡＴＴｏ＊＊ and Takashi Hama・Ａ＊＊＊ Abstract This scientific report consists of three sections. Section l is new observations of Shiroishi-ohsawa by Katto. Lithofacies of Silurian rocks in this location is ‘composed of massive to brecciated limestone, limestone breccia, acidic tuff and siliceous shale. Limestone is interpreted as resedimentation in origin. ； Section n is description of Silurian cephalopods from the locality by Kobayashi. This cephalopod faunule comprising five new species of Ｍｉｃｈｅｌｉｎｏｃｅｒａｓ.Ａｒｉｏｎｏｃｅｒａｓ， Ｏｒtｈｏｃｙｃｌｏｃｅｒａｓ and(？）Ｐｒｏtｏｆｅｉｏｎｏｃｅｒａｓ isUpper Silurian and ・most probably early Ludlovian in age. As ａ result of its comparison with other Asian cephalopods. it is found that the faunal connection was ･maintained from Central Europe to Eastern Asia through Middle Asia and Southern Tibet in the ａｇｅ･ Section Ⅲ is an advance report on ａ new trilobite collection from the locality by Kobayashi and Hamada. Among the trilobites eight species in six genera and five families including three new species ｏｆ召乙£ｍαｓ£uswere distinguished The early Upper Silurian age of the Ｃｃｒａｕｒｏｉｄｅｓ ｏｒｉｅｎtaliｓ horizon at Gomi limestone quarry is further confirmed with this collection. INTRODUCTION This paper･ is a “ omnibus” paper in which three independent sections are included : the geology of Shiroishi-ohsawa in Mt. Yokokura, Shikoku and two palaeontological papers on cephalopods and trilobites｡ The fossils described in this paper were originally collected and offered to Katto by Messrs. Yukio Sako of Kushimoto･Wakayama Prefecture and Tomihiro Mizobuchi of Kochi City.
    [Show full text]
  • Midde Trias Sic Molluscan Fossils from the Humboldt Range
    Midde Trias sic Molluscan Fossils of iostratigraphic Significance from the Humboldt Range, Northwestern Nevada Middle Triassic Molluscan Fossils of Biostratigraphic Significance from the Humboldt Range, Northwestern Nevada By N. J. SILBERLING and K. M. NICHOLS GEOLOGICAL SURVEY PROFESSIONAL PAPER 1207 Taxonomic and superpositional documentation of an unusually complete faunal succession UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1982 UNITED STATES DEPARTMENT OF THE INTERIOR JAMES G. WATT, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director Library of Congress Cataloging in Publication Data Silberling, Norman John, 1928- Middle Triassic molluscan fossils of biostratigraphic significance from the Humboldt Range, northwestern Nevada. (Geological Survey Professional Paper 1207) Bibliography: p. 71 Supt. of Docs. No.: I 19.16: 1207 1. Mollusks, Fossil. 2. Paleontology Triassic 3. Geology, Stratigraphic Triassic. 4. Geology Nevada Humboldt Range. I. Nichols, Kathryn Marion, 1946- joint author. II. Title. III. Series: United States. Geological Survey. Professional Paper 1207. QE801.S64 564 80-607925 For sale by the Distribution Branch, U.S. Geological Survey 604 South Pickett Street, Alexandria, VA 22304 CONTENTS Page Page Abstract ---------------------------------------- 1 Paleontology Continued Introduction ------------------------------------ 1 Systematic descriptions Continued History ------------------------------------- 1 Class Cephalapoda Continued Description of study and acknowledgments 3 Subclass Ammonoidea Continued Stratigraphic
    [Show full text]
  • Connecting Ring Structure and Its Significance for Classification of the Orthoceratid Cephalopods
    Connecting ring structure and its significance for classification of the orthoceratid cephalopods HARRY MUTVEI Mutvei, H. 2002. Connecting ring structure and its significance for classification of the orthoceratid cephalopods. Acta Palaeontologica Polonica 47 (1): 157–168. The connecting ring in orthoceratids is composed of two calcified layers: an outer spherulitic−prismatic and an inner cal− cified−perforate. The spherulitic−prismatic layer is a direct continuation of that layer in the septal neck, whereas the calci− fied−perforate layer is a structurally modified continuation of the nacreous layer of the septal neck. The latter layer is tra− versed by numerous pores which are oriented either transversally to the siphuncular surface, or have a somewhat irregu− larly anastomosing course. The connecting ring structure is positively correlated to the dorsal position of the scars of the cephalic retractor muscles. A similar type of connecting ring and a dorsal postion of retractor muscle scars also occur in lituitids, previously assigned to tarphyceratids, and in baltoceratids, previously assigned to ellesmeroceratids. These two taxa are therefore included in the suborder Orthoceratina, which, together with the suborder Actinoceratina, are assigned to the order Orthoceratida Kuhn, 1940. Key words: Orthoceratina, Actinoceratina, siphuncular structure, connecting ring. Harry Mutvei [[email protected]], Department of Palaeozoology, Swedish Museum of Natural History, Box 50007, SE−10405 Stockholm, Sweden. Introduction (Orthoceratidae); “Michelinoceras” sp. (Michelinoceratidae); Geisonoceras kinnekullense (Foord, 1887) (Geisonoceratidae); Polygrammoceras oelandicum Troedsson, 1932(Troedssonel− Shell structure in most Paleozoic nautiloids is imperfectly lidae); Lituites sp., Rhynhorthoceras sp. (Lituitidae); Cochlio− preserved owing to diagenetic transformation of shell ar− ceras spp. (Baltoceratidae). Silurian: Dawsonoceras sp.
    [Show full text]