Table Of ContentTopics in Geobiology 39
M. Gabriela Mángano
Luis A. Buatois Editors
The Trace-Fossil
Record of Major
Evolutionary Events
Volume 1: Precambrian and Paleozoic
Topics in Geobiology
Volume 39
The Topics in Geobiology series covers the broad discipline of geobiology that is
devoted to documenting life history of the Earth. A critical theme inherent in
addressing this issue and one that is at the heart of the series is the interplay between
the history of life and the changing environment. The series aims for high quality,
scholarly volumes of original research as well as broad reviews.
Geobiology remains a vibrant as well as a rapidly advancing and dynamic fi eld.
Given this fi eld’s multidiscipline nature, it treats a broad spectrum of geologic,
biologic, and geochemical themes all focused on documenting and understanding
the fossil record and what it reveals about the evolutionary history of life. The
Topics in Geobiology series was initiated to delve into how these numerous facets
have infl uenced and controlled life on Earth.
Recent volumes have showcased specifi c taxonomic groups, major themes in the
discipline, as well as approaches to improving our understanding of how life has
evolved.
Taxonomic volumes focus on the biology and paleobiology of organisms – their
ecology and mode of life – and, in addition, the fossil record – their phylogeny and
evolutionary patterns – as well as their distribution in time and space.
Theme-based volumes, such as predator-prey relationships, biomineralization,
paleobiogeography, and approaches to high-resolution stratigraphy, cover specifi c
topics and how important elements are manifested in a wide range of organisms and
how those dynamics have changed through the evolutionary history of life.
Comments or suggestions for future volumes are welcomed.
Series Editors
Neil H. Landman
American Museum of Natural History, New York, USA
Peter J. Harries
Tampa, Florida, USA
More information about this series at h ttp://www.springer.com/series/6623
M. Gabriela Mángano • Luis A. Buatois
Editors
The Trace-Fossil Record of
Major Evolutionary Events
Volume 1: Precambrian and Paleozoic
Editors
M. Gabriela Mángano Luis A. Buatois
Department of Geological Sciences Department of Geological Sciences
University of Saskatchewan University of Saskatchewan
Saskatoon , Saskatchewan , Canada Saskatoon , Saskatchewan, Canada
ISSN 0275-0120
Topics in Geobiology
ISBN 978-94-017-9599-9 ISBN 978-94-017-9600-2 (eBook)
DOI 10.1007/978-94-017-9600-2
Library of Congress Control Number: 2016951934
© Springer Science+Business Media Dordrecht 2016
T his work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of
the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation,
broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information
storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology
now known or hereafter developed.
T he use of general descriptive names, registered names, trademarks, service marks, etc. in this publication
does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant
protective laws and regulations and therefore free for general use.
T he publisher, the authors and the editors are safe to assume that the advice and information in this book
are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the
editors give a warranty, express or implied, with respect to the material contained herein or for any errors
or omissions that may have been made.
Printed on acid-free paper
This Springer imprint is published by Springer Nature
The registered company is Springer Science+Business Media B.V. Dordrecht
To Dolf Seilacher, who, as usual, thought
about these issues long before us.
Fore word
I magine a world much like our own: an oxygen-rich atmosphere, dynamic tectonic
activity, and a rich and diverse biota of plants, animals, and teeming associations of
microbes. Indeed a world just like ours, with a similarly deep history of life, but
with one slight difference: no body fossils. No shark teeth eroding from cliffs, no
trilobites, no dinosaur bones cluttering up museums and the dreams of impression-
able 5-year-olds (and Hollywood moguls). Worst of all, of course, we would be
missing the remarkable schnozzle of O pabinia . Much of the rich morphological
detail provided by body fossils would be irretrievably lost, but how much of the his-
tory and diversity of life could we recover? Would we be able to identify the explo-
sive evolutionary dynamism of the Cambrian diversifi cation? Would the
paleontologists of this imaginary world be able to chart changing patterns of animal
diversity and morphological disparity? Identify the invasion of land or the great
mass extinctions? Chronicle advances in behavioral patterns? Would changing cli-
mate patterns be evident, or the rise of great plodding vertebrates?
I f we stipulate that tracks, trails, and burrows were preserved in all the detail
documented in the chapters of this volume and the richly informative photographs
and diagrams, then a remarkable detailed view of animal diversity, morphological
disparity, and behavior emerges. For those not intimately acquainted with the exten-
sive strides made over the past couple of decades of research in ichnology, this
volume illustrates the range of information which can be recovered from the pri-
mary record of organismal behavior to analysis of changing patterns of diversity and
disparity.
A s a graduate student during the early 1980s the focus of ichnology seemed to be
on describing new structures and providing them (mystifyingly to those of us who
did not study trace fossils) Latin binomials. Yet ichnology was already undergoing
a conceptual shift in concert with changes within the broader fi eld of paleobiology.
As facies concepts spread through sedimentology, the concept of ichnofacies was
adopted. The increased emphasis on taphonomy, preservation, and the quality of the
fossil record beginning in the 1980s found a similar expression in ichnology in the
recognition that the same animal could produce very different structures depending
on the environment and the nature of the sediment, and that tracks can look very
vii
viii Foreword
different depending on what level one examines within their stratigraphy. One result
of such studies has been considerable revision in the diversity of ichnotaxa. As
described in Chap. 2 of this volume, many fossils that we happily accepted as bur-
rows in the mid-1990s have now been recognized as components of a diverse assem-
blage of latest Ediacaran tubes, and not trace fossils at all. Restudy of Ediacaran
traces has drastically reduced the number of accepted ichnogenera.
To a non-ichnologist, what is particularly striking about this book is how faith-
fully the general outlines of evolutionary dynamics are visible with trace fossils
alone. As illustrated by Chaps. 2 and 3 , the integration of trace fossils has long been
standard for studies of the Ediacaran and Cambrian diversifi cation. It is not just that
the base of the Cambrian is currently defi ned by the fi rst occurrence of the ichno-
taxon T reptichnus pedum, rather it is hard to imagine any survey of the Ediacaran–
Cambrian diversifi cation n ot including a discussion of the trace-fossil record. Data
from ichnological studies has been essential to revealing patterns of morphological
novelty and innovation, which is why several generations of workers, from Dolf
Seilacher and Peter Crimes to Mary Droser, Soren Jensen and the editors of this
volume, have played critical roles in expanding our integrated understanding of this
interval. Indeed, Chap. 3 notes that in important ways the trace-fossil record may
provide a more reliable picture of the diversity dynamics during the Fortunian, the
fi rst stage of the Cambrian, than do other fossils.
T he pattern continues with later chapters. The Ordovician biodiversifi cation
event reveals breakthroughs in paleoecology including movement into infaunal
habitats with increased tiering, increased bioturbation, and colonization of new
environments (Chap. 4 ). Unlike the Cambrian, the Ordovician increase in the diver-
sity of ichnotaxa was not accompanied by an increase in ichnodisparity. Indeed a
thread throughout the chapters is the frequency of “early burst” patterns of diversi-
fi cation. The exploration and exploitation of new habitats is a consistent theme
throughout this volume. The invasion of land, discussed in Chap. 5 , reveals a pattern
of colonization, a rapid exploration of new behaviors and architectural designs, fol-
lowed by variation on the established themes. Other episodes that are addressed are
the expansion of terrestrial ecosystems, the Mesozoic marine revolution, and lacus-
trine revolutions. Chapter 1 4, on the Cenozoic mammalian radiation, suggests that
the tracks of this episode, like the traces of the Cambrian, may provide a richer
record of evolutionary change than does skeletal elements, and in addition provides
unique information on locomotion, body size, and ecology. I must confess that I had
never considered the nature of trace fossils associated with soils, but Chap. 1 5 illu-
minates the unexpected complexity in the evolutionary exploitation of paleosols.
Chapter 1 6 provides an insightful analysis of patterns of ecospace occupation
through the Phanerozoic, advances in ecosystem engineering, and patterns of ichno-
diversity and ichnodisparity. I was particularly struck by the proposal that a space of
all possible “ichno-structures” that was explored relatively early by marine inverte-
brate clades, with similar architectures subsequently discovered independently by
different clades. Not surprisingly, this pattern matches studies of ecospace by
Bambach and colleagues, and of morphological disparity by many writers.
Foreword ix
B ut of course the diversity and disparity of these structures varied with events in
the history of life, as demonstrated by ichnological studies associated with the end-
Permian, end-Triassic, and end-Cretaceous mass extinctions, as discussed in Chaps.
7 , 8 , and 1 2. The early Triassic aftermath of the end-Permian mass extinction reveals
as complicated a pattern of ichnofaunal re-emergence as has been found looking
just at body fossils. Returning to the counterfactual musings with which I began this
foreword, the evidence presented in Chap. 7 makes it clear that we would be able to
recover much of the complexity of the biotic recovery from the trace-fossil record
alone. (I must confess to a certain pleasure in Chap. 7 as a proposal I made in 1993
which had been discarded by later workers is resurrected therein.)
Sadly of course, the trace-fossil record on my mythical, alternate Earth would be
no more complete than the record we possess today. Trace fossils might hint at mor-
phologies not found among extant animals, but phylogenetic analysis, to take one
example, would be greatly hampered by a loss of character information from the
early history of many clades: the origins of turtles might forever remain a mystery.
There would be many questions accessible with our extant fossil record that would
be unanswerable. But of course this is just the strength of the fossil record that we
possess. The trace and body fossil records each have their strength, and their weak-
nesses. This volume wonderfully elucidates the power of the ichnofossil record,
properly interpreted, to reveal much of the ecological and evolutionary dynamics of
life on this Earth. As students read this volume (and I hope many do), the chapters
here should provide a plethora of questions to pursue. While I am sure that this book
will attract many students to ichnology, in some ways the most signifi cant impact of
the book would be to convince paleontologists to more fully integrate ichnological
data and analyses into projects on evolutionary diversifi cations and radiations, mass
extinctions, and paleoecological dynamics.
Douglas H. Erwin
Department of Paleobiology
National Museum of Natural History
Washington , DC , USA
Contents
1 The Conceptual and Methodological Tools of Ichnology .................... 1
Nicholas J. Minter , Luis A. Buatois , and M. Gabriela Mángano
2 Ediacaran Ecosystems and the Dawn of Animals ................................ 27
Luis A. Buatois and M. Gabriela Mángano
3 The Cambrian Explosion ....................................................................... 73
M. Gabriela Mángano and Luis A. Buatois
4 The Great Ordovician Biodiversifi cation Event ................................... 127
M. Gabriela Mángano , Luis A. Buatois , Mark Wilson ,
and Mary Droser
5 The Prelude to Continental Invasion .................................................... 157
Nicholas J. Minter , Luis A. Buatois , M. Gabriela Mángano ,
Robert B. MacNaughton , Neil S. Davies , and Martin R. Gibling
6 The Establishment of Continental Ecosystems .................................... 205
Nicholas J. Minter , Luis A. Buatois , M. Gabriela Mángano ,
Neil S. Davies , Martin R. Gibling , and Conrad Labandeira
7 The End-Permian Mass Extinction ....................................................... 325
Richard Hofmann
Index ................................................................................................................. 351
xi
Prol ogue
“A beginning has been made and the discipline has been
advanced to the point where some of the highlights in the
history of life may be examined from a paleoecological
perspective”
(Valentine 1973, Evolutionary Paleoecology
of the Marine Biosphere)
In a remarkable book on the meaning of geologic time, Stephen Jay Gould explored
the dichotomy between time’s arrow and time’s cycle (Gould 1987). According to
this view, time’s arrow encompasses history as an irreversible sequence of unrepeat-
able events, whereas time’s cycle refers to a nondirectional time characterized by
repetition according to a recurrent pattern. As we have emphasized elsewhere (e.g.,
Mángano and Buatois 2012, 2015), ichnology can be viewed as an expression of the
tension between these two faces of geologic time.
The remarkable success of ichnology to solve problems in facies analysis,
paleoenvironmental reconstruction, and sequence stratigraphy is clearly an expres-
sion of the emphasis on recurrence. In fact, the very same defi nition of archetypal
ichnofacies, as trace-fossil suites that record responses of benthic organisms to a
given set of environmental conditions and that recur through geologic time, epito-
mizes time’s cycle. In this view, regardless of the age of the unit animals should
respond to ecological parameters in a similar way, refl ecting their adaptation to the
environment they inhabit. This nomothetic program for ichnology, with its power as
a predictive conceptual tool, is the reason that sedimentary geologists now typically
include trace fossils in their toolkit to scrutinize the stratigraphic record.
H owever, this success when dealing with practical issues, often of economic
importance, should not prevent us from the realization that ichnology has much to
contribute to our understanding of the changing ecology of the past by recovering a
time’s arrow perspective. While working on a previous book (Buatois and Mángano
2011), it became increasingly obvious to us that this other face of ichnology has
xiii
