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.. We can see how rapi

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

Andrey Yu Zhuravlev and Robert Riding

Introduction

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-chorhemichor-dates, various worms, and minor problematic animals, are not

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.

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

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  Chengjiang fauna, EB  Emu Bay Shale, MC  Mount Cup Formation, SB  Sinsk fauna, SP  Sirius Passet

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

Holmia kjerulfi

Holmia inusitata Schmidtiellus mikwitzi

Rusophycus parallelum

Platysolenites antiquissimus

Sabellidites "Rovno"

Skiagia ornata/

Fimbriaglomerella membranacea

Heliosphaeridium dissimilare/

Skiagia ciliosa

Asteridium Comasphaeridium velvetum

Trilobite, Small Shelly Fossil, and Ichnofossil Zones

Morocco Baltic Platform Laurentia Avalonia

Tissafinian

Banian

Issendalenian

SP MC

*511 Ma

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

Late Templetonian/

*495 Ma

Erixanium sentum

Wentsua iota/

Rhaptagnostus apsis

Rhaptagnostus clarki patulus/

Caznaia squamosa/

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  Burgess Shale, KF  Kaili Formation, MF  Marjum Formation, OR 

orsten, WF Wheeler Formation In addition, in some chapters the Corynexochid,

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.