DOCSLIB.ORG

Paleoecology and Taphonomy of Ediacaran Macrofossils from the Khatyspyt Formation, Olenek

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Paleoecology and Taphonomy of Ediacaran Macrofossils from the Khatyspyt Formation, Olenek Paleoecology and Taphonomy of Ediacaran macrofossils from the Khatyspyt Formation, Olenek Uplift, Siberia Natalia Vladimirovna Bykova Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Geosciences Shuhai Xiao Benjamin C. Gill Sterling Nesbitt Brian Romans August 30, 2017 Blacksburg, Virginia Keywords: Geobiology, Paleobiology, Paleoecology, Taphonomy Copyright 2017 © N. Bykova Paleoecology and Taphonomy of Ediacaran macrofossils from the Khatyspyt Formation, Olenek Uplift, Siberia Natalia Vladimirovna Bykova ABSTRACT The Ediacaran Period (635 – 541 Ma) is a critical transition in the history of the Earth and life. It is marked by the appearance of enigmatic Ediacara-like fossils and macroalgae, which had existed since the early Proterozoic, but started to diversify morphologically and ecologically during this geological period. Nevertheless, paleontologists have been studying Ediacaran fossils for more than a century, the key questions about these fossils remain unanswered, including their phylogenetic affinities, taphonomic history, ecology, and paleoenvironmental distribution. Thus, new ways of investigation need to be employed to unveil enigmas of Ediacaran organisms. As well as, scientists need to engage other representatives of Ediacaran assemblages, such as macroalgae, to fully understand how those communities operated in the past. The chapters of this original research in this dissertation demonstrate innovative approaches and methods for studying the paleoecology and taphonomy of Ediacaran macrofossils. The second chapter presents the results of a geochemical analysis to resolve taphonomic and paleoecological questions about the Ediacara-like discoidal holdfast fossil Aspidella. Stable isotope data of organic carbon, carbonate carbon/oxygen, and pyrite sulfur were integrated with iron speciation data to reconstruct the taphonomy, paleoecology, and paleoenvironments of Aspidella fossils. The third chapter presents results from a comprehensive analysis of macroalgae from Proterozoic to early Paleozoic. In this study, a database of macroalgal fossil was updated and analyzed in order to gain insights into the big- picture evolutionary patterns of macroalgal morphology and ecology through time. These methods and approaches offer new opportunities to test major paleobiologic and geobiologic hypotheses, thus improving our understanding of the history of the biosphere and the Earth system. ACKNOWLEDGEMENTS I would like to thank everyone who has supported me on my way to a higher education; help me to develope as a scientist in the academic world; and played a role in my personal establishment. It is impossible to properly acknowledge all the people, who was helping me through all those years. Still, I want to take this opportunity to acknowledge and thank, in no particular order, the following exceptional people for their truthful support: ▪ My parents Anzhelika and Vladimir, who never limit my freedom of pursuing any of my new adventures or keep the old ones, no matter how dangerous or ambitious they were (and ironically, who probably will never be able to read these words) ▪ My sister, Olga and my brother-in-law Sergey, who basically my second parents and care for me more than I do ▪ My beautiful niece Anastasia and nephew Alex, who always keep me in the tonus and focus, as well as responsible for my change of perspective (have you ever played with ‘Magformers’? or glue sequins on the paper Cinderella? – It is very relaxing) ▪ Hector, who laughs with me on my worst jokes, as well as challenge me and believe in my success as nobody even done before ▪ My fellow graduate students—particularly those in paleontology, including Mike Meyer, Andrew (Drew 1) Hawkins, Antony (Drew 2) Muscente Qing Tang, Jesse Broce, Ken O’Donnell, Jackie Wittmer, Caitlin Colleary, Candice Stefanic, Chris Griffin, Kiersten Formoso, Krista Koeller, Mitchell Riegler, as well as visiting scholars Zhen Dai, Zhou Wang, Wei Wang, Julia Arroy, Ke Pang, Qin Ye — for fun conversations, scientific and professional discussions, constructive feedback, and generally good and peaceful times ▪ My PhD committee: Ben Gill, Brian Romans and Sterling Nesbitt ▪ My co-authors and collaborators – Ben Gill, Vladimir Rogov, Steven Loduca, Dmitry Grazhdankin – who contributed to the work in this dissertation ▪ All the faculty and staff in the Virginia Tech Department of Geosciences, especially Connie Lowe, who keeps our sanity ▪ My labmates and friends from IPGG SB RAS – Dmitry Grazhdankin, Konstantin Nagovitsin, Vladimir Rogov, Vasiliy Marusin, Anton Kolesnikov, Boris Kochnev, Galina Karlova ▪ Anatoly Gibsher my first scientific mentor and Physical Geology professor, a person because of whom I fall in love with geology and especially Pre-Cambrian one. As well as Dmitry Grazhdankin, my bachelor and master advisor, whom I can truly call a life mentor. ▪ Last, but not least, my advisor Shuhai Xiao, who gave me an opportunity for one-of-a- lifetime experience of getting my PhD abroad, as well as has been extremely helpful and generous with his knowledge and time though all this time iii ATTRIBUTIONS Chapter Two or “A geochemical study of the Ediacaran discoidal fossil Aspidella preserved in limestones: Implications for its taphonomy and paleoecology” was published in Geobiology, 2017, volume 15, pages 572-587, by N. Bykova, B. C. Gill, D. Grazhdankin, V. Rogov and S. Xiao. N. Bykova and S. Xiao conceived the project. N. Bykova, B. Gill and V. Rogov collected all data. N. Bykova and S. Xiao developed the manuscript with contributions from D. Grazhdankin and B. Gill. Chapter Three is in the final stages of preparation for submission to Paleobiology journal. The tentative title of the publication is “Seaweeds through time: Morphological and ecological analysis of Proterozoic and early Paleozoic benthic macroalgae with a focus on the Ediacaran Period” and my co-authors in the manuscript are S.T. LoDuca, M. Kowalewski, D. Grazhdankin, and S. Xiao. N. Bykova, D. Grazhdankin, S.T. LoDuca and S. Xiao conceived the project. N. Bykova and S. T. LoDuca collected data on Proterozoic and early Paleozoic macroalgal fossils respectively. N. Bykova conducted statistical analyses based on suggestions from M. Kowalewski. N. Bykova and S. Xiao developed the manuscript with contributions from S.T. LoDuca, M. Kowalewski, D. Grazhdankin. iv TABLE OF CONTENTS Abstract ...................................................................................................................................... ii Acknowledgements ................................................................................................................... iii Attributions ................................................................................................................................ iv Table of contents ........................................................................................................................ v List of figures ........................................................................................................................... vii List of tables .............................................................................................................................. ix Grant information ....................................................................................................................... x Chapter 1 OVERVIEW OF EDIACARAN PALEOECOLOGY AND TAPHONOMY .......... 1 1.1 Introduction ...................................................................................................................... 2 1.2 References ........................................................................................................................ 4 Chapter 2 A GEOCHEMICAL STUDY OF THE EDIACARAN DISCOIDAL FOSSIL ASPIDELLA PRESERVED IN LIMESTONES: IMPLICATIONS FOR ITS TAPHONOMY AND PALEOECOLOGY .......................................................................................................... 7 2.1 Abstract ............................................................................................................................. 8 2.2 Introduction ...................................................................................................................... 9 2.3 Geological setting ........................................................................................................... 13 2.4 Materials and methods .................................................................................................... 14 2.5 Results ............................................................................................................................ 18 2.6 Discussion ....................................................................................................................... 21 2.6.1 Did Aspidella holdfast host microbial symbionts? .................................................. 21 2.6.2 The taphonomy of Aspidella .................................................................................... 22 2.6.3 Water column redox conditions ............................................................................... 26 v 2.7 Conclusions .................................................................................................................... 29 2.8 Acknowledgments .......................................................................................................... 30 2.9 Tables and table captions
Load more

Recommended publications
  • Cambrian Phytoplankton of the Brunovistulicum – Taxonomy and Biostratigraphy
    MONIKA JACHOWICZ-ZDANOWSKA Cambrian phytoplankton of the Brunovistulicum – taxonomy and biostratigraphy Polish Geological Institute Special Papers,28 WARSZAWA 2013 CONTENTS Introduction...........................................................6 Geological setting and lithostratigraphy.............................................8 Summary of Cambrian chronostratigraphy and acritarch biostratigraphy ...........................13 Review of previous palynological studies ...........................................17 Applied techniques and material studied............................................18 Biostratigraphy ........................................................23 BAMA I – Pulvinosphaeridium antiquum–Pseudotasmanites Assemblage Zone ....................25 BAMA II – Asteridium tornatum–Comasphaeridium velvetum Assemblage Zone ...................27 BAMA III – Ichnosphaera flexuosa–Comasphaeridium molliculum Assemblage Zone – Acme Zone .........30 BAMA IV – Skiagia–Eklundia campanula Assemblage Zone ..............................39 BAMA V – Skiagia–Eklundia varia Assemblage Zone .................................39 BAMA VI – Volkovia dentifera–Liepaina plana Assemblage Zone (Moczyd³owska, 1991) ..............40 BAMA VII – Ammonidium bellulum–Ammonidium notatum Assemblage Zone ....................40 BAMA VIII – Turrisphaeridium semireticulatum Assemblage Zone – Acme Zone...................41 BAMA IX – Adara alea–Multiplicisphaeridium llynense Assemblage Zone – Acme Zone...............42 Regional significance of the biostratigraphic
    [Show full text]
  • The Ediacaran Frondose Fossil Arborea from the Shibantan Limestone of South China
    Journal of Paleontology, 94(6), 2020, p. 1034–1050 Copyright © 2020, The Paleontological Society. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/ licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited. 0022-3360/20/1937-2337 doi: 10.1017/jpa.2020.43 The Ediacaran frondose fossil Arborea from the Shibantan limestone of South China Xiaopeng Wang,1,3 Ke Pang,1,4* Zhe Chen,1,4* Bin Wan,1,4 Shuhai Xiao,2 Chuanming Zhou,1,4 and Xunlai Yuan1,4,5 1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Palaeoenvironment, Chinese Academy of Sciences, Nanjing 210008, China <[email protected]><[email protected]> <[email protected]><[email protected]><[email protected]><[email protected]> 2Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA <[email protected]> 3University of Science and Technology of China, Hefei 230026, China 4University of Chinese Academy of Sciences, Beijing 100049, China 5Center for Research and Education on Biological Evolution and Environment, Nanjing University, Nanjing 210023, China Abstract.—Bituminous limestone of the Ediacaran Shibantan Member of the Dengying Formation (551–539 Ma) in the Yangtze Gorges area contains a rare carbonate-hosted Ediacara-type macrofossil assemblage. This assemblage is domi- nated by the tubular fossil Wutubus Chen et al., 2014 and discoidal fossils, e.g., Hiemalora Fedonkin, 1982 and Aspidella Billings, 1872, but frondose organisms such as Charnia Ford, 1958, Rangea Gürich, 1929, and Arborea Glaessner and Wade, 1966 are also present.
    [Show full text]
  • Ediacaran) of Earth – Nature’S Experiments
    The Early Animals (Ediacaran) of Earth – Nature’s Experiments Donald Baumgartner Medical Entomologist, Biologist, and Fossil Enthusiast Presentation before Chicago Rocks and Mineral Society May 10, 2014 Illinois Famous for Pennsylvanian Fossils 3 In the Beginning: The Big Bang . Earth formed 4.6 billion years ago Fossil Record Order 95% of higher taxa: Random plant divisions domains & kingdoms Cambrian Atdabanian Fauna Vendian Tommotian Fauna Ediacaran Fauna protists Proterozoic algae McConnell (Baptist)College Pre C - Fossil Order Archaean bacteria Source: Truett Kurt Wise The First Cells . 3.8 billion years ago, oxygen levels in atmosphere and seas were low • Early prokaryotic cells probably were anaerobic • Stromatolites . Divergence separated bacteria from ancestors of archaeans and eukaryotes Stromatolites Dominated the Earth Stromatolites of cyanobacteria ruled the Earth from 3.8 b.y. to 600 m. [2.5 b.y.]. Believed that Earth glaciations are correlated with great demise of stromatolites world-wide. 8 The Oxygen Atmosphere . Cyanobacteria evolved an oxygen-releasing, noncyclic pathway of photosynthesis • Changed Earth’s atmosphere . Increased oxygen favored aerobic respiration Early Multi-Cellular Life Was Born Eosphaera & Kakabekia at 2 b.y in Canada Gunflint Chert 11 Earliest Multi-Cellular Metazoan Life (1) Alga Eukaryote Grypania of MI at 1.85 b.y. MI fossil outcrop 12 Earliest Multi-Cellular Metazoan Life (2) Beads Horodyskia of MT and Aust. at 1.5 b.y. thought to be algae 13 Source: Fedonkin et al. 2007 Rise of Animals Tappania Fungus at 1.5 b.y Described now from China, Russia, Canada, India, & Australia 14 Earliest Multi-Cellular Metazoan Animals (3) Worm-like Parmia of N.E.
    [Show full text]
  • Cause and Consequence of Recurrent Early Jurassic Anoxia Following The
    [Palaeontology, Vol. 56, Part 4, 2013, pp. 685–709] MICROBES, MUD AND METHANE: CAUSE AND CONSEQUENCE OF RECURRENT EARLY JURASSIC ANOXIA FOLLOWING THE END-TRIASSIC MASS EXTINCTION by BAS VAN DE SCHOOTBRUGGE1*, AVIV BACHAN2, GUILLAUME SUAN3, SYLVAIN RICHOZ4 and JONATHAN L. PAYNE2 1Palaeo-environmental Dynamics Group, Institute of Geosciences, Goethe University Frankfurt, Altenhofer€ Allee 1, 60438, Frankfurt am Main, Germany; email: [email protected] 2Geological and Environmental Sciences, Stanford University, 450 Serra Mall, Stanford, CA 94305, USA; emails: [email protected], [email protected] 3UMR, CNRS 5276, LGLTPE, Universite Lyon 1, F-69622, Villeurbanne, France; email: [email protected] 4Academy of Sciences, University of Graz, Heinrichstraße 26, 8020, Graz, Austria; email: [email protected] *Corresponding author. Typescript received 19 January 2012; accepted in revised form 23 January 2013 Abstract: The end-Triassic mass extinction (c. 201.6 Ma) Toarcian events are marked by important changes in phyto- was one of the five largest mass-extinction events in the his- plankton assemblages from chromophyte- to chlorophyte- tory of animal life. It was also associated with a dramatic, dominated assemblages within the European Epicontinental long-lasting change in sedimentation style along the margins Seaway. Phytoplankton changes occurred in association with of the Tethys Ocean, from generally organic-matter-poor the establishment of photic-zone euxinia, driven by a general sediments during the
    [Show full text]
  • Stuttgarter Beiträge Zur Naturkunde
    ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Stuttgarter Beiträge Naturkunde Serie B [Paläontologie] Jahr/Year: 1977 Band/Volume: 26_B Autor(en)/Author(s): Ziegler Bernhard Artikel/Article: The "White" (Upper) Jurassic in Southern Germany 1- 79 5T(J 71^^-7 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at Stuttgarter Beiträge zur Naturkunde Herausgegeben vom Staatlichen Museum für Naturkunde in Stuttgart Serie B (Geologie und Paläontologie), Nr. 26 .,.wr-..^ns > Stuttgart 1977 APR 1 U 19/0 The "White" (Upper) Jurassic D in Southern Germany By Bernhard Ziegler, Stuttgart With 11 plates and 42 figures 1. Introduction The Upper part of the Jurassic sequence in southern Germany is named the "White Jurassic" due to the light colour of its rocks. It does not correspond exactly to the Upper Jurassic as defined by the International Colloquium on the Jurassic System in Luxembourg (1962), because the lower Oxfordian is included in the "Brown Jurassic", and because the upper Tithonian is missing. The White Jurassic covers more than 10 000 square kilometers between the upper Main river near Staffelstein in northern Bavaria and the Swiss border west of the lake of Konstanz. It builds up the Swabian and the Franconian Alb. Because the Upper Jurassic consists mainly of light limestones and calcareous marls which are more resistent to the erosion than the clays and marls of the underlying Brown (middle) Jurassic it forms a steep escarpment directed to the west and northwest. To the south the White Jurassic dips below the Tertiary beds of the Molasse trough.
    [Show full text]
  • Poropat Et Al 2017 Reappraisal Of
    Alcheringa For Peer Review Only Reappraisal of Austro saurus mckillopi Longman, 1933 from the Allaru Mudstone of Queensland, Australia’s first named Cretaceous sauropod dinosaur Journal: Alcheringa Manuscript ID TALC-2017-0017.R1 Manuscript Type: Standard Research Article Date Submitted by the Author: n/a Complete List of Authors: Poropat, Stephen; Swinburne University of Technology, Department of Chemistry and Biotechnology; Australian Age of Dinosaurs Natural History Museum Nair, Jay; University of Queensland, Biological Sciences Syme, Caitlin; University of Queensland, Biological Sciences Mannion, Philip D.; Imperial College London, Earth Science and Engineering Upchurch, Paul; University College London, Earth Sciences, Hocknull, Scott; Queensland Museum, Geosciences Cook, Alex; Queensland Museum, Palaeontology & Geology Tischler, Travis; Australian Age of Dinosaurs Natural History Museum Holland, Timothy; Kronosaurus Korner <i>Austrosaurus</i>, Dinosauria, Sauropoda, Titanosauriformes, Keywords: Australia, Cretaceous, Gondwana URL: http://mc.manuscriptcentral.com/talc E-mail: [email protected] Page 1 of 126 Alcheringa 1 2 3 4 5 6 7 1 8 9 1 Reappraisal of Austrosaurus mckillopi Longman, 1933 from the 10 11 12 2 Allaru Mudstone of Queensland, Australia’s first named 13 14 For Peer Review Only 15 3 Cretaceous sauropod dinosaur 16 17 18 4 19 20 5 STEPHEN F. POROPAT, JAY P. NAIR, CAITLIN E. SYME, PHILIP D. MANNION, 21 22 6 PAUL UPCHURCH, SCOTT A. HOCKNULL, ALEX G. COOK, TRAVIS R. TISCHLER 23 24 7 and TIMOTHY HOLLAND 25 26 27 8 28 29 9 POROPAT , S. F., NAIR , J. P., SYME , C. E., MANNION , P. D., UPCHURCH , P., HOCKNULL , S. A., 30 31 10 COOK , A. G., TISCHLER , T.R.
    [Show full text]
  • SVP's Letter to Editors of Journals and Publishers on Burmese Amber And
    Society of Vertebrate Paleontology 7918 Jones Branch Drive, Suite 300 McLean, VA 22102 USA Phone: (301) 634-7024 Email: [email protected] Web: www.vertpaleo.org FEIN: 06-0906643 April 21, 2020 Subject: Fossils from conflict zones and reproducibility of fossil-based scientific data Dear Editors, We are writing you today to promote the awareness of a couple of troubling matters in our scientific discipline, paleontology, because we value your professional academic publication as an important ‘gatekeeper’ to set high ethical standards in our scientific field. We represent the Society of Vertebrate Paleontology (SVP: http://vertpaleo.org/), a non-profit international scientific organization with over 2,000 researchers, educators, students, and enthusiasts, to advance the science of vertebrate palaeontology and to support and encourage the discovery, preservation, and protection of vertebrate fossils, fossil sites, and their geological and paleontological contexts. The first troubling matter concerns situations surrounding fossils in and from conflict zones. One particularly alarming example is with the so-called ‘Burmese amber’ that contains exquisitely well-preserved fossils trapped in 100-million-year-old (Cretaceous) tree sap from Myanmar. They include insects and plants, as well as various vertebrates such as lizards, snakes, birds, and dinosaurs, which have provided a wealth of biological information about the ‘dinosaur-era’ terrestrial ecosystem. Yet, the scientific value of these specimens comes at a cost (https://www.nytimes.com/2020/03/11/science/amber-myanmar-paleontologists.html). Where Burmese amber is mined in hazardous conditions, smuggled out of the country, and sold as gemstones, the most disheartening issue is that the recent surge of exciting scientific discoveries, particularly involving vertebrate fossils, has in part fueled the commercial trading of amber.
    [Show full text]
  • Isabel Clifton Cookson
    1 The first Australian palynologist: Isabel Clifton Cookson 2 (1893–1973) and her scientific work 3 JAMES B. RIDING AND MARY E. DETTMANN 4 5 RIDING, J.B. & DETTMANN, M.E., The first Australian palynologist: Isabel Clifton 6 Cookson (1893–1973) and her scientific work. Alcheringa. 7 8 Isabel Clifton Cookson (1893–1973) of Melbourne, Australia, was one of that country’s 9 first professional woman scientists. She is remembered as one of the most eminent 10 palaeontologists of the twentieth century and had a distinguished research career of 58 11 years, authoring or co-authoring 93 scientific publications. Isabel worked with great 12 distinction on modern and fossil plants, and pioneered palynology in Australia. She was a 13 consumate taxonomist and described, or jointly described, a prodigious total of 110 14 genera, 557 species and 32 subspecific taxa of palynomorphs and plants. Cookson was a 15 trained biologist, and initially worked as a botanist during the 1920s. At the same time she 16 became interested in fossil plants and then, Mesozoic–Cenozoic terrestrial (1940s–1950s) 17 and aquatic (1950s–1970s) palynomorphs. Cookson’s research into the late Silurian–Early 18 Devonian plants of Australia and Europe, particularly the Baragwanathia flora, between 19 the 1920s and the 1940s was highly influential in the field of early plant evolution. The 20 fossil plant genus Cooksonia was named for Isabel in 1937 by her principal mentor in 21 palaeobotany, Professor William H. Lang. From the 1940s Cookson focussed on Cenozoic 1 22 floras and, with her students, elucidated floral affinities by comparative analyses of 23 micromorphology, anatomy and in situ pollen/spores between fossil and extant taxa.
    [Show full text]
  • Geobiological Events in the Ediacaran Period
    Geobiological Events in the Ediacaran Period Shuhai Xiao Department of Geosciences, Virginia Tech, Blacksburg, VA 24061, USA NSF; NASA; PRF; NSFC; Virginia Tech Geobiology Group; CAS; UNLV; UCR; ASU; UMD; Amherst; Subcommission of Neoproterozoic Stratigraphy; 1 Goals To review biological (e.g., acanthomorphic acritarchs; animals; rangeomorphs; biomineralizing animals), chemical (e.g., carbon and sulfur isotopes, oxygenation of deep oceans), and climatic (e.g., glaciations) events in the Ediacaran Period; To discuss integration and future directions in Ediacaran geobiology; 2 Knoll and Walter, 1992 • Acanthomorphic acritarchs in early and Ediacara fauna in late Ediacaran Period; • Strong carbon isotope variations; • Varanger-Laplandian glaciation; • What has happened since 1992? 3 Age Constraints: South China (538.2±1.5 Ma) 541 Ma Cambrian Dengying Ediacaran Sinian 551.1±0.7 Ma Doushantuo 632.5±0.5 Ma 635 Ma 635.2±0.6 Ma Nantuo (Tillite) 636 ± 5Ma Cryogenian Nanhuan 654 ± 4Ma Datangpo 663±4 Ma Neoproterozoic Neoproterozoic Jiangkou Group Banxi Group 725±10 Ma Tonian Qingbaikouan 1000 Ma • South China radiometric ages: Condon et al., 2005; Hoffmann et al., 2004; Zhou et al., 2004; Bowring et al., 2007; S. Zhang et al., 2008; Q. Zhang et al., 2008; • Additional ages from Nama Group (Namibia), Conception Group (Newfoundland), and Vendian (White Sea); 4 The Ediacaran Period Ediacara fossils Cambrian 545 Ma Nama assemblage 555 Ma White Sea assemblage 565 Ma Avalon assemblage 575 Ma 585 Ma Doushantuo biota 595 Ma 605 Ma Ediacaran Period 615 Ma
    [Show full text]
  • “Modern-Type Plate Tectonics”?
    SILEIR RA A D B E E G D E A O D L Special Session, “A tribute to Edilton Santos, a leader in Precambrian O E I G C I A Geology in Northeastern Brazil”, edited by A.N. Sial and V.P. Ferreira O BJGEO S DOI: 10.1590/2317-4889202020190095 Brazilian Journal of Geology D ESDE 1946 Dawn of metazoans: to what extent was this influenced by the onset of “modern-type plate tectonics”? Umberto G. Cordani1* , Thomas R. Fairchild1 , Carlos E. Ganade1 , Marly Babinski1 , Juliana de Moraes Leme1 Abstract The appearance of complex megascopic multicellular eukaryotes in the Ediacaran occurred just when the dynamics of a cooling Earth allowed establishment of a new style of global tectonics that continues to the present as “modern-type plate tectonics”. The advent of this style was first registered in 620 Ma-old coesite-bearing Ultra-High Pressure eclogites within the Transbrasiliano-Kandi mega-shear zone along the site of the West Gondwana Orogeny (WGO). These eclogites comprise the oldest evidence of slab-pull deep subduction capable of inducing con- tinental collisions and producing high-relief Himalayan-type mega-mountains. Life, prior to this time, was essentially microscopic. Yet with increasing Neoproterozoic oxygenation and intensified influx of nutrients to Ediacaran oceans, resulting from the erosion of these mountains, complex macroscopic heterotrophic eukaryotes arose and diversified, taking the biosphere to a new evolutionary threshold. The repeated elevation of Himalayan-type mega-mountains ever since then has continued to play a fundamental role in nutrient supply and biosphere evolution. Other authors have alluded to the influence of Gondwana mountain-building upon Ediacaran evolution, however we claim here to have identified when and where it began.
    [Show full text]
  • The Ediacaran–Cambrian Transition: the Emerging Record from Small Carbonaceous Fossils (Scfs)
    38 The Ediacaran–Cambrian transition: the emerging record from Small Carbonaceous Fossils (SCFs) Ben J. Slater1, Thomas H.P. Harvey2, Romain Guilbaud3, Sebastian Willman1, Graham E. Budd1, Nicholas J. Butterfield4. 1Department of Earth Sciences (Palaeobiology), Uppsala University, Villavägen 16, SE-75236 Uppsala, Sweden ([email protected]) 2School of Geography, Geology and the Environment, University of Leicester, Leicester LE1 7RH, UK 3Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK. 4Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK Abstract.––The most profound change in the fossil record is centered on the Ediacaran–Cambrian transition. Sediments deposited near to this boundary record the first complex trace fossils, the first animal biomineralizers and the earliest fossils of the major animal groups that came to define the subsequent Phanerozoic fossil record. Here we discuss how the emerging record of small carbonaceous fossils (SCFs) is shedding new light on unmineralized aspects of the biota from this critical evolutionary transition. The new SCFs record complements currently established records from trace fossils and biomineralized shelly-remains in reconstructing the broader scale macroevolutionary patterns of this transition, but via an entirely different taphonomic window. SCFs extend the record of multiple major animal groups, improve our picture of protistan diversity from this interval, and reveal new data on elements of the biota that span the Ediacaran–Cambrian boundary. Key words: small carbonaceous fossils; bilateria; Burgess Shale-type preservation; Ediacaran; Terreneuvian. The dramatic changes in the fossil record across subsequent Cambrian radiation (Butterfield, the Ediacaran–Cambrian transition seemingly 2003; Slater et al., 2018a).
    [Show full text]
  • New High‐Resolution Age Data from the Ediacaran–Cambrian Boundary Indicate Rapid, Ecologically Driven Onset of the Cambrian Explosion
    Received: 14 June 2018 | Revised: 6 October 2018 | Accepted: 19 October 2018 DOI: 10.1111/ter.12368 PAPER New high‐resolution age data from the Ediacaran–Cambrian boundary indicate rapid, ecologically driven onset of the Cambrian explosion Ulf Linnemann1 | Maria Ovtcharova2 | Urs Schaltegger2 | Andreas Gärtner1 | Michael Hautmann3 | Gerd Geyer4 | Patricia Vickers-Rich5,6,7 | Tom Rich6 | Birgit Plessen8 | Mandy Hofmann1 | Johannes Zieger1 | Rita Krause1 | Les Kriesfeld7 | Jeff Smith7 1Senckenberg Collections of Natural History Dresden, Museum of Mineralogy Abstract and Geology, Dresden, Germany The replacement of the late Precambrian Ediacaran biota by morphologically disparate 2Département des Sciences de la Terre, animals at the beginning of the Phanerozoic was a key event in the history of life on University of Geneva, Genève, Switzerland ‐ 3Paläontologisches Institut und Museum, Earth, the mechanisms and the time scales of which are not entirely understood. A Zürich, Switzerland composite section in Namibia providing biostratigraphic and chemostratigraphic data 4 Bayerische Julius-Maximilians-Universität, bracketed by radiometric dating constrains the Ediacaran–Cambrian boundary to Lehrstuhl für Geodynamik und Geomaterialforschung, Würzburg, Germany 538.6–538.8 Ma, more than 2 Ma younger than previously assumed. The U–Pb‐CA‐ID 5Department of Chemistry and TIMS zircon ages demonstrate an ultrashort time frame for the LAD of the Ediacaran Biotechnology, Swinburne University of Technology, Melbourne (Hawthorne), biota to the FAD of a complex, burrowing Phanerozoic biota represented by trace fos- Victoria, Australia sils to a 410 ka time window of 538.99 ± 0.21 Ma to 538.58 ± 0.19 Ma. The extre- 6 Museums Victoria, Melbourne, Victoria, mely short duration of the faunal transition from Ediacaran to Cambrian biota within Australia less than 410 ka supports models of ecological cascades that followed the evolution- 7School of Earth, Atmosphere and Environment, Monash University, ary breakthrough of increased mobility at the beginning of the Phanerozoic.
    [Show full text]