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Ichnology
Organism–substrate interactions in space and time
Ichnology is the study of traces, such as burrows, trackways,
and borings, created in the substrate by living organisms. It is an
increasingly important field, having recently been transformed
into a multifaceted science at the crossroads of many disciplines.
This is the first book to systematically cover the conceptual
framework of the discipline and the wide breadth of applica-
tions in both paleobiology and sedimentology, bridging the
gap between the two main facets of the field. It emphasizes the
importance of understanding ecological controls on benthic
fauna distribution and the role of burrowing organisms in chan-
ging their environments.
A detailed analysis of the ichnology of a full range of dep-
ositional environments is presented using examples from the
Precambrian to the Recent, and the use of trace fossils in facies
analysis and sequence stratigraphy is discussed. By presenting
ichnological information within a macroevolutionary perspec-
tive, the authors provide an up-to-date overview of the subject
and highlight the potential of biogenic structures to provide valu-
able information and solve problems in a wide range of fields.
An invaluable resource for researchers and graduate students
in paleontology as well as in sedimentology and sequence stra-
tigraphy, this book will also be of interest to oil industry profes-
sionals working in reservoir and exploration geology.
luis a. buatois is a Full Professor at the University of
Saskatchewan, specializing in paleoenvironmental and strati-
graphic aspects of ichnology. He has received awards from the
Argentinean Paleontological Association, the Egidio Feruglio
Foundation, and the Argentinean Academy of Sciences, and the
Argentinean Secretary of Science and Technology. Currently
President of the International Ichnological Association, and
formerly Vice-President of the International Palaeontological
Association, he has carried out field and subsurface work in
many different countries. Professor Buatois has published four
other books, edited three journal special issues, and is the author
of over 150 scientific papers. He is also a member of the editorial
board of a number of journals, including Lethaia and Ichnos.
m. gabriela mángano is an Associate Professor at the
University of Saskatchewan and works on ecological and evolu-
tionary aspects of trace fossils. In addition to her research projects
in paleontology and geology, she has a strong interest in philosophy
and the history of science. Dr Mángano has done extensive inter-
national fieldwork and, as a researcher for the National Research
Council in Argentina, she obtained awards from the Argentinean
Paleontological Association, the Mid-American Paleontological
Society, and the Argentinean Federation of University Women. She
is a member of the editorial board of a number of journals, includ-
ing Journal of Paleontology, Palaios, Paleontologia Electronica, and
Revista Brasilera de Paleontologia, has edited two special issues, and
has published three other books and more than 100 scientific papers.
Ichnology
Organism–substrate
interactions in space and time
luis a. buatois
m. gabriela mángano
University of Saskatchewan, Canada
CambriDge uniVersitY Press
Cambridge, New York, Melbourne, Madrid, Cape Town,
Singapore, São Paulo, Delhi, Tokyo, Mexico City
Cambridge University Press
The Edinburgh Building, Cambridge CB2 8RU, UK
Published in the United States of America by Cambridge University Press, New York
www.cambridge.org
Information on this title: www.cambridge.org/9780521855556
© Luis A. Buatois and M. Gabriela Mángano 2011
This publication is in copyright. Subject to statutory exception
and to the provisions of relevant collective licensing agreements,
no reproduction of any part may take place without the written
permission of Cambridge University Press.
First published 2011
Printed in the United Kingdom at the University Press, Cambridge
A catalog record for this publication is available from the British Library
Library of Congress Cataloging in Publication data
Buatois, Luis A.
Ichnology: organism-substrate interactions in space and time/Luis A. Buatois, M. Gabriela Mángano.
p. cm.
ISBN 978-0-521-85555-6 (hardback)
1. Ichnology. 2. Paleoecology. I. Mánga no, M. Gabriela. II. Title.
QE720.5.B83 2011
560’.43–dc22 2010051885
ISBN 978-0-521-85555-6 Hardback
Cambridge University Press has no responsibility for the persistence or
accuracy of URLs for external or third-party internet websites referred to in
this publication, and does not guarantee that any content on such websites is,
or will remain, accurate or appropriate.
We dedicate this book to Melanie, Gabriel, Michelle, and also
Sebastian and Milly
v
Contents
Acknowledgments xi 1.4.4 Grazing traces or pascichnia 20
1.4.5 Feeding traces or fodinichnia 20
Introduction 1
1.4.6 Dwelling traces or domichnia 21
Part I Conceptual tools and methods 1.4.7 Traps and farming traces or agrichnia 21
1 The basics of ichnology 5 1.4.8 Escape traces or fugichnia 22
1.1 Basic concepts 5 1.4.9 Equilibrium traces or equilibrichnia 22
1.2 Characteristics of trace fossils 8 1.4.10 Predation traces or praedichnia 23
1.2.1 T race fossils represent evidence of 1.4.11 Nesting traces or calichnia 24
behavior 8 1.4.12 Pupation chambers or pupichnia 24
1.2.2 T he same organism may produce more 1.4.13 Fixation/anchoring traces or fixichnia 24
than one ichnotaxon 9 1.4.14 Bioclaustration structures or impedichnia 24
1.2.3 T he same ichnotaxon may be produced 1.4.15 Discussion: complex traces and extended
by more than one organism 10 organisms 24
1.2.4 M ultiple architects may produce a single 2 Taxonomy of trace fossils 25
structure 10 2.1 Approach and philosophy 25
1.2.5 P roducers are commonly soft-bodied 2.2 Some problems and practical guidelines 26
animals that are rarely preserved 11 2.3 Ichnotaxobases 27
1.2.6 T race fossils are commonly preserved 2.3.1 General form 28
in rock units that are otherwise 2.3.2 Wall and lining 28
unfossiliferous 12 2.3.3 Branching 29
1.2.7 T he same biogenic structure may be 2.3.4 Fill 30
differentially preserved in various 2.3.5 Spreite 31
substrates 12 2.4 Compound and composite trace fossils 31
1.2.8 T race fossils commonly have long 2.4.1 Compound trace fossils 31
stratigraphic ranges 13 2.4.2 Composite trace fossils 33
1.2.9 T race fossils commonly have narrow 2.5 Hierarchies in ichnotaxonomy 34
environmental ranges 14 2.6 Vertebrate ichnotaxonomy 35
1.2.10 Trace fossils are rarely transported 14 2.7 The uncertainty principle in ichnotaxonomy 36
1.3 Preservation of trace fossils 14 2.8 Classification of trace fossils in outcrops and
1.3.1 Stratinomic classifications 14 cores 36
1.3.2 P hysiochemical processes of
3 Paleobiology of trace fossils 38
preservation and alteration 17
3.1 Modes of life 38
1.4 Ethology of trace fossils 17
3.1.1 Feeding strategy 38
1.4.1 Resting traces or cubichnia 18
3.1.2 Position with respect to the
1.4.2 Locomotion traces or repichnia 20
substrate–water interface 43
1.4.3 Death traces or mortichnia 20
3.1.3 Level of motility 43
vii
Contents viii
3.2 Modes of interaction with the substrate 44 6.1.1 Hydrodynamic Energy 99
3.3 Locomotion and burrowing mechanisms 46 6.1.2 Substrate 101
3.3.1 M ultiple modes of locomotion: the 6.1.3 Oxygenation 104
empiricist approach 46 6.1.4 Salinity 107
3.3.2 B urrowing pre-adaptations: the 6.1.5 Sedimentation rate 109
morpho-structural approach 55 6.1.6 Food supply 110
3.3.3 I n search of a universal mechanism: the 6.1.7 Bathymetry 111
rationalist approach 56 6.1.8 Water turbidity 113
3.4 Movement ecology 57 6.1.9 Climate 113
4 The ichnofacies model 58 6.1.10 Water table 115
4.1 The ichnofacies concept 58 6.2 Role of taphonomy 116
4.2 Softground marine ichnofacies 59 6.3 Ichnodiversity and ichnodisparity 117
4.2.1 Psilonichnus ichnofacies 59 6.4 Population strategies 119
4.2.2 Skolithos ichnofacies 60 6.5 Resident and colonization ichnofaunas 119
4.2.3 Cruziana ichnofacies 62 6.6 Ecosystem engineering 120
4.2.4 Zoophycos ichnofacies 64 6.7 Organism–organism interactions 121
4.2.5 Nereites ichnofacies 65 6.8 Spatial heterogeneity 123
4.3 Substrate-controlled ichnofacies 67 7 Ichnology of shallow-marine clastic environments 126
4.3.1 Glossifungites ichnofacies 67 7.1 Wave-dominated shallow marine 126
4.3.2 Trypanites ichnofacies 69 7.1.1 Backshore 128
4.3.3 Gnathichnus ichnofacies 71 7.1.2 Foreshore 131
4.3.4 Teredolites ichnofacies 71 7.1.3 Upper shoreface 131
4.4 Invertebrate continental ichnofacies 73 7.1.4 Middle shoreface 131
4.4.1 Scoyenia ichnofacies 73 7.1.5 Lower shoreface 132
4.4.2 Mermia ichnofacies 75 7.1.6 Offshore transition 136
4.4.3 Coprinisphaera ichnofacies 76 7.1.7 Upper offshore 136
4.4.4 Termitichnus ichnofacies 77 7.1.8 Lower offshore 139
4.4.5 Celliforma ichnofacies 77 7.1.9 Shelf 139
4.4.6 Octopodichnus–Entradichnus ichnofacies 78 7.2 Tide-dominated shallow marine 139
4.5 Vertebrate ichnofacies 79 7.2.1 Supratidal marsh and mangroves 141
4.5.1 Chelichnus ichnofacies 80 7.2.2 Mud flat 143
4.5.2 Grallator ichnofacies 80 7.2.3 Mixed flat 145
4.5.3 Brontopodus ichnofacies 80 7.2.4 Sand flat 145
4.5.4 Batrachichnus ichnofacies 80 7.2.5 Tidal channels and creeks 146
4.5.5 Characichichnos ichnofacies 80 7.2.6 Subtidal sandbars and tidal dunes 146
4.6 Pitfalls and confusions in ichnofacies analysis 80 7.3 Mixed tide- and wave-influenced shorelines 147
5 The ichnofabric approach 83 7.3.1 Wave-dominated tidal flats 148
5.1 Tiering 83 7.3.2 Tidal beaches 150
5.2 Ichnofabrics: concepts and methods 84 7.4 Muddy shorelines 150
5.2.1 Q uantifying bioturbat ion and 8 Ichnology of marginal-marine environments 152
illustrating ichnofabrics 84 8.1 Estuaries 152
5.2.2 Taphonomy of ichnofabrics 85 8.1.1 Wave-dominated estuaries 152
5.3 Types of ichnofabrics 86 8.1.2 Tide-dominated estuaries 156
5.4 The ichnoguild concept 87 8.2 Bays 160
5.5 Paleosol ichnofabrics 90 8.2.1 Restricted bays 160
5.6 The role of bioturbation, bioerosion, and 8.2.2 Open bays 162
biodeposition 91 8.3 Deltas 163
5.7 Bioturbation-enhanced permeability and 8.3.1 River-dominated deltas 165
reservoir characterization 91 8.3.2 Wave-dominated deltas 169
5.8 Critical evaluation: ichnofabrics versus 8.3.3 Tide-dominated deltas 174
ichnofacies or ichnofabrics and ichnofacies? 96 8.4 Fjords 175
9 Ichnology of deep-marine clastic environments 181
Part II Spatial trends
9.1 Slopes 181
6 Trace fossils and paleoecology 99 9.1.1 Topographically simple slopes 181
6.1 Response to environmental parameters 99 9.1.2 Topographically complex slopes 184
