The Ecology of the Cambrian Radiation - Andrey Zhuravlev - Chapter 1 doc

THE CAMBRIAN RADIATION, which commenced around 550 million years ago, arguably ranks as the single most important episode in the development of Earth’s marine biota. Diverse benthic communities with complex tiering, trophic webs, and niche partitioning, together with an elaborate pelagic realm, were established soon af- ter the beginning of the Cambrian period. This key event in the history of life changed the marine biosphere and its associated sediments forever. At first glance, abiotic factors such us climate change, transgressive-regressive sea level cycles, plate movements, tectonic processes, and the type and intensity of vol- canism appear very significant in the shaping of biotic evolution. We can see how rapid rates of subsidence, as expressed in transgressive system tracts on the Australian cra- ton, selectively affected the diversity of organisms such as trace fossil producers, ar- chaeocyath sponges, and trilobites (Gravestock and Shergold—chapter 6); how glob- ally increased rates of subsidence and uplift accompanied dramatic biotic radiation by increasing habitat size and allowing phosphorus- and silica-rich waters to invade platform interiors (Brasier and Lindsay—chapter 4); how climatic effects, coupled with intensive calc-alkaline volcanism, at the end of the Middle Cambrian may have caused a shift from aragonite- to calcite-precipitating seas, providing suitable con- ditions for development of the hardground biota (Seslavinsky and Maidanskaya— chapter 3; Eerola—chapter 5; Guensburg and Sprinkle—chapter 19); how the re- organization of plate boundaries (Smith—chapter 2; Seslavinsky and Maidanskaya) created conditions for current upwelling, which may in turn have been responsible for the appearance and proliferation of acritarch phytoplankton and many Early Cam- brian benthic organisms (Brasier and Lindsay; Ushatinskaya—chapter 16; Moldowan et al.—chapter 21). However, biotic factors themselves played a remarkable role in the environmental changes that formed the background to the Cambrian radiation. We see how, by means of biomineralization, shell beds and calcite debris contributed to the appearance of hardground communities (Droser and Li—chapter 7; Rozhnov—chapter 11); how CHAPTER ONE Andrey Yu. Zhuravlev and Robert Riding Introduction 01-C1099 8/10/00 2:02 PM Page 1 the intensification of bioturbation not only obliterated sedimentary structures but also increased aeration of deeper sediments and provided more space for the development of infauna (Brasier and Lindsay; Droser and Li; Crimes— chapter 13); how the Early Cambrian biota changed the quality of seawater, thereby allowing the radiation of di- verse phototrophic communities (Zhuravlev—chapter 8; Burzin et al.—chapter 10); how the appearance of framework-building organisms created habitats for diverse reefal communities (Pratt et al.—chapter 12; Debrenne and Reitner—chapter 14; Riding— chapter 20); how the introduction of mesozooplankton in the Eltonian pyramid (in addition to predator and herbivore pressure) produced a cascade of eco- logic and evolutionary events in both the pelagic and benthic realms (Butterfield— chapter 9; Zhuravlev); and, finally, how biotic diversity itself, together with commu- nity structure, conditioned the intensity of extinction events and the timing and type of abiotic factors that may have caused them (Zhuravlev). This volume comprises 20 chapters, contributed by 33 authors based in 10 countries. It has three themes: environment; community patterns and dynamics; and radiation of major groups of organisms. The focus is the Cambrian period (tables 1.1 and 1.2), but inevitably discussion of these topics also draws on related events and develop- ments in the adjacent Neoproterozoic and Ordovician time intervals. ENVIRONMENT The theme of the environment traces plate tectonic developments, paleogeographic changes, the history of transgressive-regressive cycles, sedimentary patterns, and cli- mate change, as recorded in carbon, strontium, and samarium-neodymium isotope curves, in the context of their influence on biotic development. The records of bio- turbation and shell-bed fabrics, which provide links among physical, chemical, and biologic processes, are included, and there are data on biomarkers. COMMUNITY The theme of community considers the biotas in their ecologic context, from their di- versification to the development of planktonic, level-bottom, reef, hardground, and deep-water communities. RADIATION The theme of radiation examines deployment of adaptive abilities by dominant Cam- brian groups: brachiopods, cnidarians, coeloscleritophorans, cyanobacteria, algae, echinoderms, hyoliths, lobopods, mollusks, sponges, stenothecoids, trilobites, and other arthropods. Other common groups, such as acritarchs, chaetognaths, hemichor- dates, conodont-chordates, various worms, and minor problematic animals, are not 2 Andrey Yu. Zhuravlev and Robert Riding 01-C1099 8/10/00 2:02 PM Page 2 INTRODUCTION 3 scrutinized separately, but aspects of their ecology are discussed within analyses of particular communities. Not all the views expressed in this book are in agreement, nor should they be. We hope that comparison of the facts, arguments, and ideas presented will allow the reader to judge the relative importance of abiotic and biotic factors on the dramatic evolution- ary and ecologic expansion that was the Cambrian radiation of marine life. This volume is a contribution to IGCP Project 366, Ecological Aspects of the Cam- brian Radiation. In addition, this work has involved participants from IGCP Projects 303 (Precambrian-Cambrian Event Stratigraphy), 319 (Global Paleogeography of the Late Precambrian and Early Paleozoic), 320 (Neoproterozoic Events and Resources), 368 (Proterozoic Events in East Gondwana Deposits), and 386 (Response of the Ocean/Atmosphere System to Past Global Events). MUSEUM AND REPOSITORIES ABBREVIATIONS AGSO (Australian Geological Survey Organisation, Canberra, Australia), GSC (Geo- logical Survey of Canada, Ottawa), HUPC (Harvard University Paleobotanical Collec- tion, Cambridge, USA), IGS (Iranian Geological Survey, Tehran), MNHN (Muséum National d’Histoire Naturelle, Paris, France), PIN (Paleontological Institute, Russian Academy of Sciences, Moscow), SAN (Sansha Collections, J. Reitner, Göttingen, Ger- many), SMX (Sedgwick Museum, Cambridge University, United Kingdom), UA (Uni- versity of Alaska, USA), USNM (National Museum of Natural History, Smithsonian Institution, Washington, DC, USA), UW (University of Wisconsin, USA). REFERENCES Bowring, S. A., J. P. Grotzinger, C. E. Isachsen, A. H. Knoll, S. M. Pelechaty, and P. Kolo- sov. 1993. Calibrating rates of Early Cam- brian evolution. Science 261:1293–1298. Davidek, K., E. Landing, S. R. Westrop, A. W. A. Rushton, R. A. Fortey, and J. M. Adrain. 1998. New uppermost Cambrian U-Pb date from Avalonian Wales and the age of the Cambrian-Ordovician bound- ary. Geological Magazine 132:305–309. Jago, J. B. and P. W. Haines. 1998. Recent ra- diometric dating of some Cambrian rocks in southern Australia: relevance to the Cambrian time scale. Revista Española de Paleontología, no. extraordinario, Home- naje al Prof. Gonzalo Vidal, 115–122. Landing, E., S. A. Bowring, K. Davidek, S. R. Westrop, G. Geyer, and W. Heldmaier. 1998. Duration of the Early Cambrian: U-Pb ages of volcanic ashes from Avalon and Gondwana. Canadian Journal of Earth Sciences 35:329–338. Shergold, J. H. 1995. Timescales. 1: Cam- brian. Australian Phanerozoic Timescales, Biostratigraphic Charts, and Explanatory Notes, 2d ser. Australian Geological Sur- vey Organisation Record 1995/30. Zhuravlev, A. Yu. 1995. Preliminary sugges- tions on the global Early Cambrian zona- tion. Beringeria Special Issue 2:147–160. 01-C1099 8/10/00 2:02 PM Page 3 4 Andrey Yu. Zhuravlev and Robert Riding Table 1.1 Correlation Chart for Major Lower Cambrian Regions Siberian Platform Archaeocyath Zones Archaeocyathus abacus beds Syringocnema favus beds Unnamed beds Trilobite Zones (Stages) Xystridura templetonensis/ Redlichia chinensis (Ordian/ Early Templetonian) Pararaia janeae Pararaia tatei Abadiella huoi Pararaia bunyerooensis *525 Ma Stages Canglangpuan Meishucunian Qiongzhusian Longwangmiaoan Maozhuangian Stages *535 Ma *545 Ma Toyonian Botoman Atdabanian Tommotian Nemakit- Daldynian Amgan Trilobite, Archaeocyath, and Small Shelly Fossil Zones Bergeroniellus ketemensis Bergeroniellus asiaticus Bergeroniellus micmacciformis/ Erbiella Anabarites trisulcatus 1 1 1 1 1 1 4 2 2 2 2 3 3 3 4 4 Purella antiqua Nochoroicyathus sunnaginicus Dokidocyathus regularis Dokidocyathus lenaicus/ Tumuliolynthus primigenius Nochoroicyathus kokoulini Warriootacyathus wilkawillinensis Spirillicyathus tenuis Jugalicyathus tardus Retecoscinus zegebarti Carinacyathus pinus Fansycyathus lermontovae Bergeroniellus gurarii Bergeroniellus ornata Lermontovia grandis/ Irinaecyathus shabanovi- Archaeocyathus okulitchi beds Anabaraspis splendens Schistocephalus Trilobite and Small Shelly Fossil Zones Megapalaeolenus/ Palaeolenus Drepanuroides Yunnanaspis/ Yiliangella Malungia Eoredlichia/Wutingaspis "Parabadiella"/ Mianxidiscus Lapworthella/ Tannuolina/ Sinosachites Siphogonuchites/ Paracarinachites Anabarites/ Protohertzina/ Arthrochites Redlichia nobilis Redlichia chinensis Hoffetella Australia China Yaojiayella CB EB SB 2/3 *523 Ma Stages Spain Leonian Bilbilian Marianian Cordubian Alcudian Ovetian Note: Approximate correlation of Lower Cambrian stratigraphic subdivisions for different regions, modified from Zhuravlev 1995, and the positions of key Cambrian faunas: CB ϭ Chengjiang fauna, EB ϭ Emu Bay Shale, MC ϭ Mount Cup Formation, SB ϭ Sinsk fauna, SP ϭ Sirius Passet 01-C1099 8/10/00 2:02 PM Page 4 INTRODUCTION 5 fauna. In addition, in some chapters the Waucoban corresponds to the Early Cam- brian, and the Olenellid biomere is used for Atdabanian-Toyonian. Reliable radioiso- tope ages from Bowring et al. 1993, Jago and Haines 1998, and Landing et al. 1998. Stages Hupeolenus Sectigena Antatlasia guttapluviae Antatlasia hollardi Daguinaspis Choubertella Eofallotaspis Fallotaspis tazemmourtensis Cephalopyge notabilis Ornamentapsis frequens Trilobite Zones Trilobite Zones Stages Trilobite, Small Shelly Fossil, and Ichnofossil Zones Protolenus Callavia broeggeri Camenella baltica Sunnaginia imbricata Harlaniella podolica Watsonella crosbyi No fauna known No fauna known "Ladatheca" cylindrica "Phycodes" pedum Branchian Placentian Albertella Plagiura/Poliella Bonnia/ Olenellus "Nevadella" "Fallotaspis" "Kibartay" Volkovia dentifera/ Liepaina plana Acritarch Zones Eccaparadoxides insularis Proampyx linnarssoni Holmia kjerulfi Holmia inusitata Schmidtiellus mikwitzi Rusophycus parallelum Platysolenites antiquissimus Sabellidites "Rovno" Skiagia ornata/ Fimbriaglomerella membranacea Heliosphaeridium dissimilare/ Skiagia ciliosa Asteridium tornatum/ Comasphaeridium velvetum Trilobite, Small Shelly Fossil, and Ichnofossil Zones Morocco Baltic Platform Laurentia Avalonia Tissafinian Banian Issendalenian SP MC *511 Ma 01-C1099 8/10/00 2:02 PM Page 5 6 Andrey Yu. Zhuravlev and Robert Riding Table 1.2 Correlation Chart for Major Middle and Late Cambrian Maozhuangian Xuzhuangian Zhangxian Kushanian Changshanian Fengshanian Xingchangian Cordylodus lindstromi Cordylodus prolindstromi Hirsutodontus simplex Cordylodus proavus Mictosaukia perplexa Lophosaukia Rhaptagnostus clarki prolatus/ Caznaia sectatrix Irvingella tropica Stigmatoa diloma Proceratopyge cryptica Glyptagnostus reticulatus Glyptagnostus stolidotus Acmarhachis quasivespa Glyptagnostus reticulatus Pseudagnostus "curtare" Pseudagnostus pseudangustilobus Ivshinagnostus ivshini Oncagnostus longifrons Oncagnostus kazachstanicus Oncagnostus ovaliformis Neoagnostus quadratiformis Trisulcagnostus trisulcus Lotagnostus hedini Dikelokephalina Euloma limitaris/ Batyraspis Lophosaukia Harpidoides/Troedsonia Eolotagnostus scrobicularis Glyptagnostus stolidotus Agnostus pisiformis Erediaspis eretis Holteria arepo Proampyx agra Ptychagnostus cassis Goniagnostus nathorsti Ptychagnostus punctuosus Acidusus atavus Triplagnostus gibbus Xystridura templetonensis/ Euagnostus opimus Doryagnostus notalibrae Damesella torosa/ Ascionepea jantrix Idamean Mindyallan Aysokkanian Sakian Batyrbayan Iverian Payntonian Datsonian Warendian Australia Ungurian Kazakhstan & Siberia Aksayan Boomerangian Undillan Amgan Floran Late Templetonian/ *495 Ma Erixanium sentum Wentsua iota/ Rhaptagnostus apsis Rhaptagnostus clarki patulus/ Caznaia squamosa/ Hapsidocare lilyensis Peichiashania secunda/ Peichiashania glabella Peichiashania tertia/ Peichiashania quarta Sinosaukia impages Neoagnostus quasibilobus/ Shergoldia nomas China KF Redlichia chinensis Mayan Leiopyge laevigata/ Anomocarioides limbataeformis Aldanaspis truncata Anopolenus henrici/ Kounamkites Schistocephalus 1 1 2 2 3 3 4 5 6 1 1 2 2 3 1 1 3 Corynexochus perforatus Pseudanomocarina Note: Approximate correlation of Middle-Upper Cambrian stratigraphic subdivisions for different regions, modified from Shergold 1995, and the positions of key Cambrian faunas: BS ϭ Burgess Shale, KF ϭ Kaili Formation, MF ϭ Marjum Formation, OR ϭ orsten, WF ϭ Wheeler Formation. In addition, in some chapters the Corynexochid, 01-C1099 8/10/00 2:02 PM Page 6 INTRODUCTION 7 Rhabdinopora flabelliforme Canadian Ibexian Sunwaptan Steptoan Marjuman North America (Laurentia) Trempealeauan Franconian Dresbachian Albertian Rhabdinopora Yosimuraspis Richardsonella/ Platypeltoides Missisquoia perpetis Mictosaukia cf. M. orientalis Tsinania/Ptychaspis Kaolishania pustulosa Maladioidella Changshania conica Chuangia batia Drepanura Blackwelderia Damesella/Yabeia Leiopeishania Taitzuia/Poshania Amphoton Crepicephalina Bailiella/Lioparia Poriagraulos Hsuchuangia/Ruichengella Shantungaspis Yaojiayella Scandinavia Peltura transiens Peltura scarabaeoides Peltura Peltura minor Protopeltura praecursor Leptoplastus raphidophorus Leptoplastus paucisegmentatus Parabolina spinulosa Parabolina Parabolina brevispina Olenus dentatus Agnostus pisiformis OR MF BS WF OR Lejopyge laevigata Jinsella brachymetopa Hypagnostus parvifrons Tomagnostus fissus/ Acidiscus atavus Triplagnostus gibbus Eccaparadoxides pinus Glossopleura Ehmaniella Bolaspidella Cedaria Crepicephalus Aphelaspis Elvinia Dundenbergia Taenicephalus Albertella Eccaparadoxides Paradoxides paradoxissimus Paradoxides forchhammeri Ptychagnostus punctuosus Goniagnostus nathorsti Olenus gibbosus Olenus truncatus Olenus wahlenbergi Olenus attenuatus Olenus scanicus Olenus Leptoplastus crassicorne Leptoplastus ovatus Leptoplastus angustatus Leptoplastus stenotus Leptoplastus Peltura costata Westergaardia Acerocare ecorne Acerocare OR Idahoia Ellipsocephaloides Saukiella pyrene/ Rasettia magna Saukiella serotina Eurekia apopsis Missisquoia Symphysurina Saukiella junia oelandicus *492 Ma Agnostus pisiformis China (cont.) Marjumiid, Pterocephaliid, and Ptychaspid biomeres are used for Amgan, Marjuman, Step- toan, and Sunwaptan intervals, respectively. Reliable radioisotope ages from Davidek et al. 1998 and Jago and Haines 1998. 01-C1099 8/10/00 2:02 PM Page 7 01-C1099 8/10/00 2:02 PM Page 8 . Geological Sur- vey Organisation Record 19 95/30. Zhuravlev, A. Yu. 19 95. Preliminary sugges- tions on the global Early Cambrian zona- tion. Beringeria Special Issue 2 :14 7 16 0. 0 1- C1099 8 /10 /00 2:02. (Droser and Li chapter 7; Rozhnov chapter 11 ); how CHAPTER ONE Andrey Yu. Zhuravlev and Robert Riding Introduction 0 1- C1099 8 /10 /00 2:02 PM Page 1 the intensification of bioturbation not only obliterated. three themes: environment; community patterns and dynamics; and radiation of major groups of organisms. The focus is the Cambrian period (tables 1. 1 and 1. 2), but inevitably discussion of these