DOCSLIB.ORG

A Detailed Lower Triassic Conodont Biostratigraphy and Its Implications for the GSSP Candidate of the Induan–Olenekian Boundary in Chaohu, Anhui Province

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Detailed Lower Triassic Conodont Biostratigraphy and Its Implications for the GSSP Candidate of the Induan–Olenekian Boundary in Chaohu, Anhui Province Available online at www.sciencedirect.com Progress in Natural Science 18 (2008) 79–90 A detailed Lower Triassic conodont biostratigraphy and its implications for the GSSP candidate of the Induan–Olenekian boundary in Chaohu, Anhui Province Laishi Zhao a,*, Jinnan Tong a, Zhiming Sun a,b, Michael J. Orchard c a State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China b Institute of Geomechanics, Chinese Academy of Geological Science, Beijing 100081, China c Geological Survey of Canada, 101-605 Robson Street, Vancouver, Canada V6B5J3 Received 26 February 2007; received in revised form 24 April 2007; accepted 4 July 2007 Abstract Chaohu is located in a deep part of carbonate ramp on the Lower Yangtze Block, which belonged to the low-latitude eastern Tethyan archipelago during the Early Triassic. Fossils were very rich in the Lower Triassic of Chaohu. Bivalves, ammonoids, conodonts were very common throughout the Lower Triassic, while fish fossils were generally rich in some beds of the upper part. It is one of the most typical sections for the Early Triassic chronostratigraphy in the world. Although various fossils had been studied in the 1980s and 1990s, recent studies based upon new and more detailed collections from the Lower Triassic of Chaohu showed that the conodont zonation needs revision. We collected Lower Triassic conodont fossils from continuous sections of the West Pingdingshan, North Pingdingshan and South Majiashan, Chaohu, Anhui Province, and updated zonations were made for each section. Eight conodont zones have been dis- tinguished. They are, in ascending order, Hindeodus typicalis zone, Neogondolella krystyni zone, Neospathodus kummeli zone, Neospath- odus dieneri zone, Neospathodus waageni zone, Neospathodus pingdingshanensis zone, Neospathodus homeri zone, and Neospathodus anhuinensis zone. The first occurrence of Neospathodus waageni eowaageni of the N. w. eowaageni subzone (i.e. the base of the N. waageni zone) is suggested as the marker to define the Induan–Olenekian boundary. Ó 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved. Keywords: Conodont biostratigraphy; Conodont zonation; Lower Triassic; Induan–Olenekian; Chaohu in Anhui Province 1. Introduction boundary (PTB) at the base of Bed 27c of the Meishan section D, Changxing, Zhejiang Province [1]. The second Establishment of the global stratotype section and Lower Triassic stage – the Induan and Olenekian bound- point (GSSP) is one of the main purposes of the Interna- ary (IOB) has been extensively studied in recent years. tional Commission of Stratigraphy (ICS) in the past By comparing with the H. himalayica in the Gondwanan twenty years. So far about 42 GSSPs have been set up Tethys region and the H. hedenstroemi in the boreal for the expected 96 Phanerozoic stages, and the rest of region, Zakharov et al. [2,3] proposed that the Tree the GSSPs are expected to be established by 2008. The Kamnya Cape Ravine section and the Abrek Bay section Triassic had its first GSSP and its base defined in from the Russian South Primorye, which are believed to 2001, that is the GSSP of the Permian and Triassic yield a mixed Boreal and Tethyan fauna, are candidates of the Induan–Olenekian boundary, and ammonoid * Corresponding author. Tel.: +86 27 62024366; fax: +86 27 67885096. Hedenstroemia bosphorensis was suggested as the index E-mail address: [email protected] (L. Zhao). fossil to define the boundary. 1002-0071/$ - see front matter Ó 2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in China Press. All rights reserved. doi:10.1016/j.pnsc.2007.07.001 80 L. Zhao et al. / Progress in Natural Science 18 (2008) 79–90 But Dagys [4] pointed out that in the Induan and Olene- community sequences and 15 subbiocenozones based on kian boundary H. bosphorensis also occurred in the strata paleoecological studies of the rich fossils in the Majiashan where Gyronites dominates, so its age is questionable. section [32–35]. However, Hedenstroemia is a genus which prevailed in Most of the work in Chaohu focused on the biostratig- the high-latitude regions and scarcely occurred in the raphy, especially the conodont and ammonoid sequences, low-latitude regions, while Flemingites, Euflemingites, as well as the carbon and oxygen isotopic stratigraphy, Meekoceras and others have been commonly considered magnetic stratigraphy, lithostratigraphy and sedimentol- as the index fossils to identify this boundary in the low-lat- ogy. Special attention has been paid to the strata from itude regions. Though the conodonts in the high-latitude the Permian–Triassic boundary to the lower part of the regions are not so common as in the low-latitude regions, Olenekian [21–24,36–44]. So we consider the Chaohu sec- most of the key forms are still recognizable one. Therefore, tions fit for the GSSPs of the Lower Triassic boundaries, the conodonts should be considered in the definition of the maybe even the base of the Middle Triassic [20]. Induan–Olenekian boundary. Lower Triassic conodont biostratigraphy has been 2.1. North and West Pingdingshan sections of Chaohu, established in some areas of the world, such as the sections Anhui province in Lukac, Western Slovenia [5]; Tesero, Southern Alps [6]; Wadi Wasit, Central Oman [7]; Tahokamigumi and Kam- The North and West Pingdingshan sections are situ- ura, Southwest Japan [8]; Abadeh, Central Iran [9]; Muth, ated on the western limb of the Majiashan–Pingdingshan Himalaya [10,11]; Chaotian, Meishan, Bian Yang, Qing Syncline, about 3 km from the center of Chaohu and Yan and Wangmo, China [12–18]. The published data indi- north to the Chaohu Lake. At the West Pingdingshan cated that Lower Triassic conodont zonations used to section, the Lower Triassic is even better exposed except define the Induan–Olenekian boundary are very different that about 10 m strata at the base of the Lower Triassic from one area to the other in tropical Tethyan realm, even are covered by a road leading to a quarry on the hillside. for the same section. Therefore, detailed conodont study However, the Permian–Triassic boundary can still be on Lower Triassic strata at Chaohu (in centimeter scale observed. The sequence exposure around the Induan– around the Induan–Olenekian boundary) was conducted Olenekian boundary, up to the lower part of Spathian, in order to establish a complete Lower Triassic conodont is extremely good for study. The section is quite contin- sequence and its intercalibration with the ammonoid uous and all the boundaries between the formations are sequence. very distinct. Our attention was paid to the intervals around the Induan–Olenekian boundary, where continu- 2. Geological setting ous sampling was undertaken. Among the 186 samples from the 74.63 m-thick North Pingdingshan section The Lower Triassic in Chaohu is one of the well-devel- (Fig. 1), 80 yielded identifiable conodonts and some oped Lower Triassic sequences in South China. The Lower poorly preserved fragments. A total of 990 identifiable Triassic sequence of Chaohu not only yields abundant fos- elements were assigned to 40 species in 6 genera. Seven sils, but also provides a complete biostratigraphical conodont stratigraphic zones have been distinguished. sequence marked by conodonts and ammonoids [19–23], They are, in ascending order, Hindeodus typicalis zone, allowing for a well-defined chronostratigraphy. Neogondolella krystyni zone, Neospathodus kummeli zone, Early investigations on the Triassic geology of Chaohu N. dieneri zone, N. waageni zone, Neospathodus pingding- began in the 1970s. The best-studied is Lower Triassic shanensis zone, and N. homeri zone. sequence in Chaohu in the Majiashan section, where the Of the 286 horizons were sampled in the 112.8 m thick 1–200,000 regional geological survey was undertaken by West Pingdingshan section (Fig. 2), 172 productive sam- the Anhui Geological Surveying Team in the 1970s. Fossils ples contained identifiable conodonts. The extracted 2871 were very abundant and diverse throughout the Lower Tri- conodont elements included 54 stratigraphically signifi- assic, including three bivalve assemblages [24–26]. Six cant species in 11 genera: Seven conodont zones were Lower Triassic ammonoid zones were recognized in recognized in ascending order as follows: H. typicalis ascending order: Lytophiceras–Ophiceras zone, Prionolobus zone, Ng. krystyni zone, N. kummeli zone, N. dieneri zone, Flemingites zone, Anasibirites zone, Tirolites–Colum- zone, N. waageni zone, N. pingdingshanensis zone, and bites zone, and Subcolumbites zone by Guo [27] and Tong N. homeri zone (Fig. 2). et al. [28], and six conodont zones in ascending order: Clarkina carinata zone, Neospathodus dieneri zone, Neos- 2.2. South Majiashan section pathodus cristagalli zone, Neospathodus waageni zone, Icri- ospathodus collinsoni zone, and Neospathodus anhuinensis– The Lower Triassic of the Majiashan section is one of Neospathodus homeri zone by Ding [29]. Many other stud- the best-studied sequences in China. Thirty-three samples ies also found Lower Triassic ichthyosaur such as Chaohu- from 100 horizons in the 206 m South Majiashan section saurus geishanensis, Chensaurus (=Anhuihusaurus) [22], collected from the Helongshan and Nanlinghu for- chaoxianensis, C. faciles [30,31] and five Lower Triassic mations, yielded about 1000 conodonts assigned to 14 L. Zhao et al. / Progress in Natural Science 18 (2008) 79–90 81 Fig. 1. Vertical range and zonation of conodonts, ammonoids and bivalves assemblage at North Pingdingshan section, Chaohu, Anhui Province. Modified after Zhao et al. [19] Key to sub/zones: 1 = N. dieneri M2; 2 = N. dieneri M3; 3 = N. w. eowaageni;4=N. pingdingshanensis. species in 4 genera. Four conodont zones were recog- 3. Conodont zonations nized in ascending order as follows: N. waageni zone, N. pingdingshanensis zone, N. homeri zone and N. anhuin- A lot of new forms of conodonts have been extensively ensis zone. studied, and a comprehensive Lower Triassic conodont 82 L.
Load more

Recommended publications
  • 1 Revision 2 1 K-Bentonites
    1 Revision 2 2 K-Bentonites: A Review 3 Warren D. Huff 4 Department of Geology, University of Cincinnati, Cincinnati, OH 45221 USA 5 Email: [email protected] 6 Keywords: K-bentonite, bentonite, tephra, explosive volcanism, volcanic ash 7 Abstract 8 Pyroclastic material in the form of altered volcanic ash or tephra has been reported and described 9 from one or more stratigraphic units from the Proterozoic to the Tertiary. This altered tephra, 10 variously called bentonite or K-bentonite or tonstein depending on the degree of alteration and 11 chemical composition, is often linked to large explosive volcanic eruptions that have occurred 12 repeatedly in the past. K-bentonite and bentonite layers are the key components of a larger group of 13 altered tephras that are useful for stratigraphic correlation and for interpreting the geodynamic 14 evolution of our planet. Bentonites generally form by diagenetic or hydrothermal alteration under 15 the influence of fluids with high Mg content and that leach alkali elements. Smectite composition is 16 partly controlled by parent rock chemistry. Studies have shown that K-bentonites often display 17 variations in layer charge and mixed-layer clay ratios and that these correlate with physical 18 properties and diagenetic history. The following is a review of known K-bentonite and related 19 occurrences of altered tephra throughout the time scale from Precambrian to Cenozoic. 20 Introduction 21 Volcanic eruptions are often, although by no means always, associated with a profuse output 22 of fine pyroclastic material, tephra. Tephra is a term used to describe all of the solid material 23 produced from a volcano during an eruption (Thorarinsson, 1944).
    [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]
  • Exceptional Vertebrate Biotas from the Triassic of China, and the Expansion of Marine Ecosystems After the Permo-Triassic Mass Extinction
    Earth-Science Reviews 125 (2013) 199–243 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction Michael J. Benton a,⁎, Qiyue Zhang b, Shixue Hu b, Zhong-Qiang Chen c, Wen Wen b, Jun Liu b, Jinyuan Huang b, Changyong Zhou b, Tao Xie b, Jinnan Tong c, Brian Choo d a School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK b Chengdu Center of China Geological Survey, Chengdu 610081, China c State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China d Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China article info abstract Article history: The Triassic was a time of turmoil, as life recovered from the most devastating of all mass extinctions, the Received 11 February 2013 Permo-Triassic event 252 million years ago. The Triassic marine rock succession of southwest China provides Accepted 31 May 2013 unique documentation of the recovery of marine life through a series of well dated, exceptionally preserved Available online 20 June 2013 fossil assemblages in the Daye, Guanling, Zhuganpo, and Xiaowa formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate faunas was delayed by harsh environmental Keywords: conditions and then occurred rapidly in the Anisian. The key faunas of fishes and reptiles come from a limited Triassic Recovery area in eastern Yunnan and western Guizhou provinces, and these may be dated relative to shared strati- Reptile graphic units, and their palaeoenvironments reconstructed.
    [Show full text]
  • Preliminary Report on Ichthyopterygian Elements from the Early Triassic (Spathian) of Spitsbergen
    NORWEGIAN JOURNAL OF GEOLOGY Vol 98 Nr. 2 https://dx.doi.org/10.17850/njg98-2-07 Preliminary report on ichthyopterygian elements from the Early Triassic (Spathian) of Spitsbergen Christina Pokriefke Ekeheien1, Lene Liebe Delsett1, Aubrey Jane Roberts2 & Jørn Harald Hurum1 1Natural History Museum, University of Oslo, Pb.1172 Blindern, N–0318 Oslo, Norway. 2Natural History Museum, London, United Kingdom. E-mail corresponding author (Lene Liebe Delsett): [email protected] Jaw elements of Omphalosaurus sp. are described from the Early Triassic (Spathian) of Marmierfjellet, Spitsbergen. The elements are from the Grippia and the Lower Saurian niveaus in the Vendomdalen Member of the Vikinghøgda Formation. In the Grippia niveau a bonebed was excavated in 2014–15 and a large number of ichthyopterygian elements were recovered. Together with the omphalosaurian jaw elements a collection of large vertebral centra were recognized as different from the smaller Grippia centra and more than 200 large vertebral centra are referred to Ichthyopterygia indet. and tentatively assigned to regions of the vertebral column. We refrain from further assignment due to the systematic position and the difficulty of defining criteria for recognizing postcranial elements of Omphalosaurus. Keywords: Ichthyopterygia; Spitsbergen; Triassic; Omphalosaurus; Grippia bonebed Electronic Supplement A: Supplementary Material Received 23. November 2017 / Accepted 21. August 2018 / Published online 4. October 2018 Introduction The skull material is referred to Omphalosaurus based on the distinct tooth enamel, dome-shaped teeth and The Early Triassic deposits of Svalbard contain large an overall similar morphology to other specimens amounts of fish, amphibian and reptilian fossils from the of the genus (Sander & Faber, 2003).
    [Show full text]
  • Permian (Artinskian to Wuchapingian) Conodont Biostratigraphy in the Tieqiao Section, Laibin Area, South China
    Permian (Artinskian to Wuchapingian) conodont biostratigraphy in the Tieqiao section, Laibin area, South China Y.D. Suna, b*, X.T. Liuc, J.X. Yana, B. Lid, B. Chene, D.P.G. Bondf, M.M. Joachimskib, P.B. Wignallg, X.L. Laia a State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China b GeoZentrum Nordbayern, Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany c Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China d Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, Ministry of Land and Resources, Guangzhou, 510075, China e State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, 39 East Beijing Road, Nanjing, 210008, R.P. China f School of Environmental Sciences, University of Hull, Hull HU6 7RX, UK g School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK *Corresponding authors Email: [email protected] (Y.D. Sun) © 2017, Elsevier. Licensed under the Creative Commons Attribution- NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/ licenses/by-nc-nd/4.0/ 1 Abstract Permian strata from the Tieqiao section (Jiangnan Basin, South China) contain several distinctive conodont assemblages. Early Permian (Cisuralian) assemblages are dominated by the genera Sweetognathus, Pseudosweetognathus and Hindeodus with rare Neostreptognathodus and Gullodus. Gondolellids are absent until the end of the Kungurian stage—in contrast to many parts of the world where gondolellids and Neostreptognathodus are the dominant Kungurian conodonts. A conodont changeover is seen at Tieqiao and coincided with a rise of sea level in the late Kungurian to the early Roadian: the previously dominant sweetognathids were replaced by mesogondolellids.
    [Show full text]
  • Pander Society Newsletter
    Pander Society Newsletter S O E R C D I E N T A Y P 1 9 6 7 Compiled and edited by P.H. von Bitter and J. Burke PALAEOBIOLOGY DIVISION, DEPARTMENT OF NATURAL HISTORY, ROYAL ONTARIO MUSEUM, TORONTO, ON, CANADA M5S 2C6 Number 41 May 2009 www.conodont.net Webmaster Mark Purnell, University of Leicester 2 Chief Panderer’s Remarks May 1, 2009 Dear Colleagues: It is again spring in southern Canada, that very positive time of year that allows us to forget our winter hibernation & the climatic hardships endured. It is also the time when Joan Burke and I get to harvest and see the results of our winter labours, as we integrate all the information & contributions sent in by you (Thank You) into a new and hopefully ever better Newsletter. Through the hard work of editor Jeffrey Over, Paleontographica Americana, vol. no. 62, has just been published to celebrate the 40th Anniversary of the Pander Society and the 150th Anniversary of the first conodont paper by Christian Pander in 1856; the titles and abstracts are here reproduced courtesy of the Paleontological Research Institution in Ithica, N.Y. Glen Merrill and others represented the Pander Society at a conference entitled “Geologic Problem Solving with Microfossils”, sponsored by NAMS, the North American Micropaleontology Section of SEPM, in Houston, Texas, March 15-18, 2009; the titles of papers that dealt with or mentioned conodonts, are included in this Newsletter. Although there have been no official Pander Society meetings since newsletter # 40, a year ago, there were undoubtedly many unofficial ones; many of these would have been helped by suitable refreshments, the latter likely being the reason I didn’t get to hear about the meetings.
    [Show full text]
  • A Database of Triassic Conodonts from a Comprehensive Revision of Literature
    SPANISH JOURNAL OF PALAEONTOLOGY A database of Triassic conodonts from a comprehensive revision of literature Pablo PLASENCIA1,2*, Ana MÁRQUEZ-ALIAGA2 & Jingeng SHA1 1 State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Paleontology (CAS), Nanjing, 39 East Beijing Road, Nanjing, 210008, People’s Republic of China; [email protected]; [email protected] 2 Departamento de Geología, Universitat de Valencia, Dr. Moliner, 50, 46100 Burjassot, Valencia, Spain; [email protected] * Corresponding author Plasencia, P., Márquez-Aliaga, A. & Sha, J. 2013. A data base of Triassic conodonts from a comprehensive revision of literature. [Una base de datos de conodontos triásicos a partir de una completa revisión de la literatura]. Spanish Journal of Palaeontology, 28 (2), 215-226. Manuscript received 08 September 2012 © Sociedad Española de Paleontología ISSN 2255-0550 Manuscript accepted 19 December 2012 ABSTRACT RESUMEN The revision of a comprehensive amount of bibliography La revisión de una amplia cantidad de bibliografía ha hecho has made possible the development of a database containing posible el desarrollo de una base de datos en la que fi guran los the stratigraphic ranges of the conodont species from the rangos estratigráfi cos de las especies de conodontos presentes uppermost Permian and the Triassic, with a total of 336 species desde el Pérmico superior y el Triásico, con un total de 336 in 52 genera. This database is aimed at biostratigraphy and especies y 52 géneros. Esta base de datos está dirigida a la studies related to biological, evolutional and palaeodiversity bioestratigrafía y a estudios relacionados con las dinámicas dynamics.
    [Show full text]
  • Now, on to Mesozoic Marine Reptiles
    Now, on to Mesozoic Marine Reptiles NOT DINOSAURS! • They are reptiles, but some have adopted different skull fenestration • “Euryapsid” and “Anapsid” conditions are likely modified Diapsids • First reptiles returned to the sea in the Permian (Mesosaurus) How they are related: Sauropterygia Mosasauridae Thalattosuchia Dinosauria Phytosauria Lepidosauromorpha Crurotarsi Prolacertiformes Archosauromorpha Thalattosauriformes? Ichthyosauromorpha Sauria Claudiosaurus Neodiapsida Morphology • 4 basic body plans (Baupläne): (a) Thunniform advanced ichthyosaur (b) Long neck/small head plesiosaur (elasmosaur) (c) Short neck/big head pliosaur (d) Undulatory mosasaur (and basal ichthyosaur) • + “functional group 3” after Robert L. Carroll (“swimming lizards”) Morphological Trends • Limbs become rigid, often with hyperphalangy (many phalanges) • Polydactyly in ichthyosaurs Morphological Trends • (A) Merriamia (basal ichthyosaur) manus • (B) Opthalmosaurus (Jurassic ichthyosaur) manus • (C) Elasmosaurus (Cretaceous plesiosaur) manus • (D) Nothosaur pes • (E) Mosasaur pes Morphological Trends • Thoracic stiffening a usual trend • Lateral flexion directed posteriorly, or propulsion moved paraxially Carrier’s Constraint • Because of their sprawling gait, *GASP!* reptiles cannot breathe and run at the same time Ahhh… • Same applies to marine reptiles with lateral flexion (they breathe air!) *GASP!* • Solved by moving propulsion posteriorly, stiffening thorax, or moving limbs independently of spine Triassic Seas • Pangea beginning to break up • Marine
    [Show full text]
  • NOTICE: This Is the Author's Version of a Work That Was Accepted For
    NOTICE: This is the author’s version of a work that was accepted for publication in Gondwana Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Gondwana Research, Vol. 23, no. 3, 2013. doi: http://dx.doi.org/10.1016/j.gr.2012.07.002 *Manuscript Click here to view linked References 1 Early Triassic (Induan-Olenekian) conodont biostratigraphy, global anoxia, carbon 1 2 2 isotope excursions and environmental perturbations: New data from Western 3 4 5 3 Australian Gondwana. 6 7 4 8 9 1,2* 3 4 5 5 10 5 I. Metcalfe , R.S. Nicoll , R. Willink , M. Ladjavadi , & K. Grice 11 12 6 13 14 7 1. Earth Sciences, Earth Studies Building C02, School of Environmental and Rural 15 16 17 8 Science, University of New England, Armidale NSW 2351, Australia 18 19 9 2. GEMOC, ARC Centre of Excellence for Core to Crust Fluid Systems, Department 20 21 22 10 of Earth and Planetary Sciences, Macquarie University, NSW 2109 Australia 23 24 11 3. Research School of Earth Sciences, Australian National Univ., Canberra 25 26 4. 27 12 Origin Energy, Level 10, CDOP4, 135 Coronation Drive, Milton, Qld, 4064, 28 29 13 Australia 30 31 5. 32 14 WA-Organic Isotope Geochemistry Centre, Department of Chemistry, Curtin University, 33 34 15 Perth, Australia 35 36 16 37 38 39 17 * Corresponding author.
    [Show full text]
  • Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils
    Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils Ryosuke Motani1, Da-yong Jiang2,3*, Andrea Tintori4, Olivier Rieppel5, Guan-bao Chen6 1 Department of Earth and Planetary Sciences, University of California, Davis, Davis, California, United States of America, 2 Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education, Department of Geology and Geological Museum, Peking University, Beijing, People’s Republic of China, 3 State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences), Nanjing, Jiangsu Province, People’s Republic of China, 4 Dipartimento di Scienze della Terra, Universita` degli Studi di Milano, Via Mangiagalli, Milano, Italy, 5 Center of Integrative Research, The Field Museum, Chicago, Illinois, United States of America, 6 Department of Research, Anhui Geological Museum, Hefei, Anhui Province, People’s Republic of China Abstract Viviparity in Mesozoic marine reptiles has traditionally been considered an aquatic adaptation. We report a new fossil specimen that strongly contradicts this traditional interpretation. The new specimen contains the oldest fossil embryos of Mesozoic marine reptile that are about 10 million years older than previous such records. The fossil belongs to Chaohusaurus (Reptilia, Ichthyopterygia), which is the oldest of Mesozoic marine reptiles (ca. 248 million years ago, Early Triassic). This exceptional specimen captures an articulated embryo in birth position, with its skull just emerged from the maternal pelvis. Its headfirst birth posture, which is unlikely to be a breech condition, strongly indicates a terrestrial origin of viviparity, in contrast to the traditional view. The tail-first birth posture in derived ichthyopterygians, convergent with the conditions in whales and sea cows, therefore is a secondary feature.
    [Show full text]
  • High-Resolution Δ Ccarb Chemostratigraphy from Latest Guadalupian Through Earliest Triassic in South China and Iran Vladimir Davydov Boise State University
    Boise State University ScholarWorks Geosciences Faculty Publications and Presentations Department of Geosciences 8-1-2013 13 High-Resolution δ Ccarb Chemostratigraphy from Latest Guadalupian Through Earliest Triassic in South China and Iran Vladimir Davydov Boise State University NOTICE: This is the author’s version of a work that was accepted for publication in Earth and Planetary Science Letters. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Earth and Planetary Science Letters, 375 (1 Aug 2013). DOI: 10.1016/j.epsl.2013.05.020. This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Earth and Planetary Science Letters, published by Elsevier. Copyright restrictions may apply. DOI: 10.1016/j.epsl.2013.05.020. 13 High-resolution δ ccarb chemostratigraphy from latest Guadalupian through earliest Triassic in south China and Iran Shu-zhong Shen* Jonathon L. Payne State Key Laboratory of Paleobiology and Department of Geological and Environmental Stratigraphy Sciences Nanjing Institute of Geology and Palaeontology Stanford University 39 East Beijing Road Stanford, CA94305, USA Nanjing 210008, China Vladimir I. Davydov Chang-qun Cao Department of Geosciences State Key Laboratory of Paleobiology
    [Show full text]
  • New Permian-Triassic Conodont Data from Selong (Tibet) and the Youngest Occurrence of Vjalovognathus
    This is a repository copy of New Permian-Triassic conodont data from Selong (Tibet) and the youngest occurrence of Vjalovognathus. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/116518/ Version: Accepted Version Article: Wang, L, Wignall, PB, Sun, Y et al. (3 more authors) (2017) New Permian-Triassic conodont data from Selong (Tibet) and the youngest occurrence of Vjalovognathus. Journal of Asian Earth Sciences, 146. pp. 152-167. ISSN 1367-9120 https://doi.org/10.1016/j.jseaes.2017.05.014 (c) 2017 Elsevier Ltd. This manuscript version is made available under the CC BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Accepted Manuscript New Permian-Triassic conodont data from Selong (Tibet) and the youngest oc- currence of Vjalovognathus Lina Wang, Paul B. Wignall, Yadong Sun,
    [Show full text]