Fundamentals of Invertebrate Palaeontology: Microfossils [1st ed. 2020] 978-81-322-3960-4, 978-81-322-3962-8

Table of contents :
Front Matter ....Pages i-xvii
Chitinozoa (Sreepat Jain)....Pages 1-25
Acritarchs (Sreepat Jain)....Pages 27-42
Pollen and Spores (Sreepat Jain)....Pages 43-65
Dinoflagellates (Sreepat Jain)....Pages 67-92
Conodonts (Sreepat Jain)....Pages 93-115
Radiolarians (Sreepat Jain)....Pages 117-130
Marine Diatoms (Sreepat Jain)....Pages 131-142
Ostracods (Sreepat Jain)....Pages 143-170
Benthic Foraminifera (Sreepat Jain)....Pages 171-192
Calcareous Nannofossils (Sreepat Jain)....Pages 193-260
Calpionellids (Sreepat Jain)....Pages 261-277
Back Matter ....Pages 279-323

Citation preview

Springer Geology

Sreepat Jain

Fundamentals of Invertebrate Palaeontology Microfossils

Springer Geology Series Editors Yuri Litvin, Institute of Experimental Mineralogy, Moscow, Russia Abigail Jiménez-Franco, Del. Magdalena Contreras, Mexico City, Estado de México, Mexico Soumyajit Mukherjee, Earth Sciences, IIT Bombay, Mumbai, Maharashtra, India Chalina Tatiana Olegovna, Inst. of Problems in Mechanics, Russian Academy of Sciences, Moscow, Russia

The book series Springer Geology comprises a broad portfolio of scientific books, aiming at researchers, students, and everyone interested in geology. The series includes peer-reviewed monographs, edited volumes, textbooks, and conference proceedings. It covers the entire research area of geology including, but not limited to, economic geology, mineral resources, historical geology, quantitative geology, structural geology, geomorphology, paleontology, and sedimentology.

More information about this series at http://www.springer.com/series/10172

Sreepat Jain

Fundamentals of Invertebrate Palaeontology Microfossils

123

Sreepat Jain Department of Applied Geology Adama Science and Technology University Adama, Ethiopia

ISSN 2197-9545 ISSN 2197-9553 (electronic) Springer Geology ISBN 978-81-322-3960-4 ISBN 978-81-322-3962-8 (eBook) https://doi.org/10.1007/978-81-322-3962-8 © Springer Nature India Private Limited 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms 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. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The 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, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature India Private Limited The registered company address is: 7th Floor, Vijaya Building, 17 Barakhamba Road, New Delhi 110 001, India

For my son Parth And my wife Archna

Preface

The Fundamentals of Invertebrate Palaeontology (Microfossils) is a follow-up of my earlier book, Fundamentals of Invertebrate Palaeontology (Macrofossils), and like the latter, the present book does not deal with the basic principles or classification (the latter is mentioned only in brief). This book primarily deals in detailing up-to-date morphological characteristics of the studied organism and hence is intended for undergraduate students or for early researchers. Through illustrations of over 3000 hand-drawn diagrams, this book is divided into four sections with eleven chapters. The first section includes organic-walled microfossils (Chitinozoans, Acritarchs, Pollen and Spores, and Dinoflagellates), followed by the next section on phosphatic Conodonts. The third section includes siliceous microfossils (Radiolarians and Diatoms), and the last section is about calcareous microfossils (Ostracods, Foraminifera, Calcareous nannofossils, and Calpionellids) (Fig. 1). Each chapter starts with a very brief Introduction section emphasizing the relevance of the studied group and includes a series of biostratigraphic tables through time marking the stratigraphic position of index fossils. For this, a computer program, TSCreator version 7.4 (www.timescalecreator.org), is used that is based on the 2016 age model of Ogg et al. (2016). The next section elaborates the general morphology of the studied group through a series of detailed and well-labeled line diagrams (this is the main emphasis of this book). Attempt is made to illustrate the morphology of the group through line diagrams, but in one chapter (Foraminifera), actual specimen photographs are used to better illustrate the finer nuances of the group’s morphology. Additionally, for this section, throughout this book, attempt is also made to follow a bulleted pattern to enumerate morphology. However, due to the morphological complexity of the studied groups and to maintain succinctness of the text, this bulleted approach could not be followed in letter and spirit. The general morphology section is followed by brief notes on classification and geological history with up-to-date references at the end of the chapter. At the end of this book, a list of all species illustrated is provided. In this list, wherever possible, age and up-to-date species identification and assignments have been taken due care (particularly so for the Calcareous nannofossils species, where data from the Nannotaxa Web site proved immensely useful). vii

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Preface

Fig. 1 The figure shows the layout the book - four sections with eleven chapters (the Pollen and Spores form a single chapter). The first section includes organic-walled microfossils (Chitinozoans, Acritarchs, Pollen and Spores, and Dinoflagellates), the next section deals with phosphatic Conodonts., third with siliceous microfossils (Radiolarians and Diatoms), and the last section is about calcareous microfossils microfossils (Ostracods, Foraminifera, Calcareous nannofossils, and Calpionellids)

This book would not have seen the light of the day without the support and encouragement of my wife, Archna, and my son, Parth; this book is rightfully dedicated to them. I would also like to profusely thank Elsevier (Palaeoworld) for granting permission to reproduce some of the figures in this book (specifics mentioned in the respective figure captions), to Dr. Michael A. Kaminski (Saudi Arabia), Editor-in-Chief, Micropaleontology, for not only granting permission but also allowing photographs to be used for the Foraminifera chapter, to Dr. Jeremy Young (UK) for granting permission to use figures for the Calcareous nannofossils chapter, to Dr. Julio Rodriguez Lazaro for sending high-resolution figures to use for the Ostracod chapter, and to Drs. Justyna Kowal-Kasprzyk and Mohamed Benzaggagh for the Calpionellid chapter. I am also very grateful to Artai A. Santos for providing insightful suggestions in improving

Preface

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the Pollen and Spore chapter and to Dr. Mohamed Benzaggagh for the Calpionellid chapter; all the above have also been duly acknowledged in the figure captions. Last but not least, I thank Dr. Mikhail Rogov (Russia) for literature help. I once again thank them all from the depth of my heart for their time, help, and kindness. Adama, Ethiopia

Sreepat Jain

References Ogg, J. G., Ogg, G., & Gradstein, F. M. (2016). A Concise Geologic Time Scale (pp. 240). Amsterdam: Elsevier. https://timescalecreator.org. https://www.mikrotax.org/Nannotax3/.

Contents

1

Chitinozoa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 General Morphology . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Chamber Shape . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Ornamentation and Surface Patterns . . . . . . . . . 2.3 Linear Linkage Arrangements. . . . . . . . . . . . . . 3 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Aboral Pole . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Aboral Scar . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Aboral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Anti-apertural Pole . . . . . . . . . . . . . . . . . . . . . . 3.5 Apertural Plug . . . . . . . . . . . . . . . . . . . . . . . . . 3.6 Apertural Pole . . . . . . . . . . . . . . . . . . . . . . . . . 3.7 Aperture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8 Apex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 Apical Structure . . . . . . . . . . . . . . . . . . . . . . . . 3.10 Appendices . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.11 Axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.12 Basal Callus . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13 Basal Edge . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14 Basal Margin . . . . . . . . . . . . . . . . . . . . . . . . . . 3.15 Basal Pore . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16 Basal Scar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.17 Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.18 Callus (Basal) . . . . . . . . . . . . . . . . . . . . . . . . . . 3.19 Carina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.20 Catenary Structure (Chain-Like Structure) . . . . 3.21 Central Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 3.22 Chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.23 Chamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.24 Cluster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.25 Coiled Chain (=Helicoidal Chain) . . . . . . . . . . 3.26 Collar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.27 Collarette (=Collar) . . . . . . . . . . . . . . . . . . . . . . 3.28 Copula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.29 Crests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.30 Diameter (=D) . . . . . . . . . . . . . . . . . . . . . . . . .

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3.31 External Structures . . . . . . . . . 3.32 Fenestrate . . . . . . . . . . . . . . . . 3.33 Flank . . . . . . . . . . . . . . . . . . . 3.34 Flexure . . . . . . . . . . . . . . . . . . 3.35 Glabrous . . . . . . . . . . . . . . . . . 3.36 Inner Layer . . . . . . . . . . . . . . . 3.37 Laciniated . . . . . . . . . . . . . . . . 3.38 Linear Chain . . . . . . . . . . . . . . 3.39 Linkage Structures . . . . . . . . . 3.40 Lip . . . . . . . . . . . . . . . . . . . . . 3.41 Longitudinal Axis . . . . . . . . . . 3.42 Margin . . . . . . . . . . . . . . . . . . 3.43 Mesh-Like . . . . . . . . . . . . . . . 3.44 Mucron . . . . . . . . . . . . . . . . . . 3.45 Neck . . . . . . . . . . . . . . . . . . . . 3.46 Operculum . . . . . . . . . . . . . . . 3.47 Oral Scar . . . . . . . . . . . . . . . . 3.48 Oral . . . . . . . . . . . . . . . . . . . . 3.49 Ornamentation . . . . . . . . . . . . 3.50 Outer Layer . . . . . . . . . . . . . . 3.51 Peduncle . . . . . . . . . . . . . . . . . 3.52 Perforated . . . . . . . . . . . . . . . . 3.53 Processes . . . . . . . . . . . . . . . . 3.54 Prosome . . . . . . . . . . . . . . . . . 3.55 Rica . . . . . . . . . . . . . . . . . . . . 3.56 Sculpture . . . . . . . . . . . . . . . . 3.57 Septa . . . . . . . . . . . . . . . . . . . 3.58 Shoulder . . . . . . . . . . . . . . . . . 3.59 Sleeve . . . . . . . . . . . . . . . . . . . 3.60 Spines . . . . . . . . . . . . . . . . . . . 3.61 Spiny Ornamentation . . . . . . . 3.62 Vesicle . . . . . . . . . . . . . . . . . . 3.63 Wall . . . . . . . . . . . . . . . . . . . . 4 Chitinozoan Affinity. . . . . . . . . . . . . . 5 Classification . . . . . . . . . . . . . . . . . . . 6 General History and Distribution . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . 2

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Acritarchs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 General Morphology . . . . . . . . . . . . . . . . . . . . . 2.1 Sphaeromorphs and Acanthomorphs . . . . 2.2 Morphogroups . . . . . . . . . . . . . . . . . . . . 2.3 Vesicle . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Excystment Opening. . . . . . . . . . . . . . . . 3 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Geological History and Distribution . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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3

Pollen and Spores . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . 2 Spore Morphology . . . . . . . . . . . 3 Pollen Morphology . . . . . . . . . . 3.1 Pollen Units . . . . . . . . . . 3.2 Polarity . . . . . . . . . . . . . . 3.3 Apertures . . . . . . . . . . . . 3.4 Shape . . . . . . . . . . . . . . . 3.5 Symmetry . . . . . . . . . . . . 3.6 Size . . . . . . . . . . . . . . . . 4 Sporoderm Stratification. . . . . . . 4.1 Exine Ornamentation . . . 5 Earliest Plants . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . .

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Dinoflagellates . . . . . . . . . 1 Introduction . . . . . . . . 2 General Morphology . 2.1 Cyst Types . . . 2.2 Archeopyle . . . 3 Geological History . . . References . . . . . . . . . . . . .

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Conodonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 General Morphology . . . . . . . . . . . . . . . . . 2.1 Elements . . . . . . . . . . . . . . . . . . . . . 2.2 Composite Elements . . . . . . . . . . . . 2.3 Simple Elements . . . . . . . . . . . . . . . 2.4 Element Notation and Apparatus . . 3 Classification . . . . . . . . . . . . . . . . . . . . . . . 4 Geological History . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Radiolarians . . . . . . . . . . . 1 Introduction . . . . . . . . 2 Morphology . . . . . . . . 3 Geological History . . . References . . . . . . . . . . . . .

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Marine Diatoms . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . 2 Morphology . . . . . . . . . . . . 3 Terminology . . . . . . . . . . . 3.1 Gross Morphology . 3.2 Cell Wall Structure .

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4 Geological History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 5 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 Ostracods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 General Morphology . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 The Carapace and Associated Structures . . . . . 2.2 Lamellae and Cardinals . . . . . . . . . . . . . . . . . . 2.3 Pore Canals . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Muscle Scars . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 Carapace Orientation . . . . . . . . . . . . . . . . . . . . 2.6 Valve Closure . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 Sculpture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Sexual Dimorphism, Ontogeny, and Morphology of the Carapace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 General History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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149 151 151 169

Benthic Foraminifera. . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 External Morphological Features . . . . . . . . . . . . 2.1 Test Shape . . . . . . . . . . . . . . . . . . . . . . . 2.2 Chamber Arrangement . . . . . . . . . . . . . . 2.3 Chamber Form . . . . . . . . . . . . . . . . . . . . 2.4 Position of Primary Aperture . . . . . . . . . 2.5 Aperture Form . . . . . . . . . . . . . . . . . . . . 2.6 Wall Structure and Test Composition . . . 2.7 Sutures . . . . . . . . . . . . . . . . . . . . . . . . . . 2.8 Ornamentation . . . . . . . . . . . . . . . . . . . . 3 Geological History . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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171 171 171 175 175 178 178 181 182 183 184 185 191

10 Calcareous Nannofossils . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Morphology of Coccoliths . . . . . . . . . . . . . . . . . . . . . . 2.1 Heterococcoliths . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Holococcoliths . . . . . . . . . . . . . . . . . . . . . . . . . 3 Terminology for Heterococcoliths and Nannoliths . . . . 3.1 Coccolith Orientation . . . . . . . . . . . . . . . . . . . . 3.2 Central Area and Rim. . . . . . . . . . . . . . . . . . . . 3.3 Coccolith Outline and Axial Ratio . . . . . . . . . . 3.4 Ultrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 Element Shapes . . . . . . . . . . . . . . . . . . . . . . . . 3.6 Element Modifications . . . . . . . . . . . . . . . . . . . 3.7 Types of Openings . . . . . . . . . . . . . . . . . . . . . . 3.8 Element Curvature . . . . . . . . . . . . . . . . . . . . . . 3.9 Parts of Rims . . . . . . . . . . . . . . . . . . . . . . . . . .

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193 193 194 196 196 196 196 202 205 207 208 208 210 210 210

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3.10 Directions on the Rim . . . . . . . . . . . . . . . . . . . . . . . 3.11 Element Arrangement as Seen in Plan View . . . . . . 3.12 Coccolith Arrangement . . . . . . . . . . . . . . . . . . . . . . . Terms Used in Describing the Parts of a Holococcolith. . . . 4.1 Holococcolith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Crystallite Arrangement . . . . . . . . . . . . . . . . . . . . . . 4.3 Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Rim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Pore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 Proximal Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Proximal Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Wall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11 Distal Cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.12 Proximal Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.13 Septum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.14 Depression . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terms Used in Describing the Entire Holococcolith . . . . . . 5.1 Cavate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Septate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Solid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Morphological Types . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Central Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 Structural Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 Orientation in Profile . . . . . . . . . . . . . . . . . . . . . . . . 5.8 Orientation in Plan View . . . . . . . . . . . . . . . . . . . . . 5.9 Structures Spanning Central Area . . . . . . . . . . . . . . . 5.10 Structures Closing Central Area . . . . . . . . . . . . . . . . Crystallography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Crystallographic Orientation . . . . . . . . . . . . . . . . . . . Nannolith Shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 Dibrachiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Compact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Radiate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Rod-Shaped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Central Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 Free Rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7 Convex Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8 Stellate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Taxon-Based Terminology . . . . . . . . . . . . . . . . . 8.1 Braarudosphaeraceae . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Ceratolithaceae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 Discoasters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 Fasciculiths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5 Helicosphaera . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.6 Nannoconids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.7 Sphenoliths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

211 212 212 213 213 213 213 213 213 213 213 213 213 213 213 215 215 215 215 215 215 215 215 216 216 216 216 216 218 219 219 219 219 219 219 221 221 221 222 222 222 222 224 224 225 227 227 228

xvi

Contents

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Brief Note on Classification and Illustration of Major Families . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 10 Geological History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258

11 Calpionellids. . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . 2 General Morphology . . . . . . . . . . . . . 3 Geological History and Distribution . . 4 Classification . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . .

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261 261 261 265 265 275

Species List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

About the Author

Dr. Sreepat Jain is a Professor at the Department of Applied Geology, Adama Science and Technology University, Adama, Ethiopia. With over two decades of teaching and research experience, Prof. Jain holds two doctorates, one from India and the other from the United States. Prof. Jain has been awarded the “TA Excellence in Teaching” for meritorious teaching in the United States and has also received the prestigious “Prof. S. K. Singh Memorial Gold Medal” for best research paper from the Palaeontological Society of India (India). He has published several research articles in national and international peer-reviewed journals and has authored four books, two of which, Fundamental of Physical Geology (Springer) and Fundamental of Invertebrate Palaeontology: Macrofossils (Springer) are recommended for undergraduate Earth Science courses at several American universities. Both these Springer books have also received excellent international reviews. Prof. Jain also serves a reviewer for several international geoscience journals.

xvii

1

Chitinozoa

1

Introduction

The Chitinozoa (Greek words “chitin” = organic; “zoa” = animal) are flask-, urn-, or bottle-shaped, hollow organic vesicles of uncertain biological affinity, first described by Eisenack (1930) from the erratic boulders strewn near the town of Königsberg in Eastern Prussia (present-day Kaliningrad, Russia). The term “Chitinozoa” was introduced because it was thought that their walls were of chitin (a naturally occurring biopolymer; a polysaccharide) and that the vesicles were of a zoological origin (Eisenack 1931). The chitinozoans first appeared in the Early Ordovician, evolved rapidly in the Paleozoic, and thereafter went extinct by the end of the Devonian (Fig. 1(1)). Although few chitinozoans have been reported from the Carboniferous and Permian, but these are considered either suspect or reworked. Recently, the earliest chitinozoans have been reported from the Cambrian (*510 Ma), from southern China (Shen et al. 2013) (see Fig. 1). These earliest forms (Eisenackitina? sp.) are well-preserved phosphatized flask-shaped vesicles (see Fig. 1(2–10). The fact that the chitinozoans occur in almost all types of marine deposits, and that their walls are resistant to oxidation, thermal alteration, and the recrystallization of rock matrix, makes them an indispensable tool for regional and global biostratigraphic correlation. They are among the most useful index taxa for the Ordovician–Silurian duration (Tables 1, 2, 3 and 4) and have

also proved useful in delineating the Ordovician– Silurian GSSP boundaries (Vandenbroucke 2004; Verniers and Vandenbroucke 2006), auxiliary GSSP boundaries (Hennissen et al. 2010), and stage boundaries (Bergström et al. 2009; Webby et al. 2010a). The latter includes the GSSP of the Sandbian (Vandenbroucke 2004), Pridoli (Kriz et al. 1986), Lochkovian (=Silurian–Devonian boundary) (Paris et al. 1981), Pragian (Chlupác et al. 1985), and Famennian (Paris et al.1996). The GSSP is the Global Boundary Stratotype Section and Point, a reference point on a stratigraphic section that defines the lower boundary of a stage on the geologic time scale..

2

General Morphology

The chitinozoan vesicle (Fig. 2(1)) ranges from 30 to 1500 lm, but most are between 150 and 300 lm long (Gabbott et al. 1998). The vesicle possesses a two-layered *5-lm thick wall composed of a dark brown or black chitin-like substance called pseudochitin (Fig. 2(1)). Although, so far, even in well-preserved specimens, no chitin-related organic compounds have been reported (Jacob et al. 2007). The chitinozoan vesicle shows three major morphological types (Fig. 2(1, 3, and 4)); the vesicle also shows variations in its shape (Fig. 2(5 and 6)). However, the basic element of a vesicle is the bulging chamber called the Central cavity that once housed the organism (Figs. 2 and 3).

© Springer Nature India Private Limited 2020 S. Jain, Fundamentals of Invertebrate Palaeontology, Springer Geology, https://doi.org/10.1007/978-81-322-3962-8_1

1

2 Table 1 Chitinozoan biozonation (465–459 Ma) (continued…)

1

Chitinozoa

2

General Morphology

3

Fig. 1 Cambrian Stage 5 chitinozoan Eisenackitina? sp. from Gaotai Formation in Duyun, Guizhou, China (after Shen et al. 2013). 1: Stratigraphic position of Eisenackitina? sp., showing that Chitinozoa have their roots in the Cambrian explosion, and illustrating possibility of benthic origin for the group (after Shen et al. 2013). Genus-level diversify curve of marine metazoans is after Alroy et al. (2008), and chronological distribution and biodiversification (10–70: Mean number of species per million years) of chitinozoans are based largely on Grahn and Paris (2011). GOBE—Great Ordovician Biodiversification Event. 2–10 after Shen et al. (2013). 2–3: Vase-shaped vesicle; 3: Detail of aperture with flaring collarette; 4: Detail of copula with perforations (arrowed) around base. 5–7: Vase-shaped vesicle with broken aperture: 5: Lateral view; 6: Posterior view showing hollow copula blocked by residue near boundary between copula and vesicle bottom; 7: Reverse view of 5 showing perforations (arrowed) around base of copula. 8–10: Internal mold showing broken aperture and copula with laterally expanding edge: 8: Lateral view; 9: Posterior view showing blocked vesicle; 10: Detail of perforations? (arrows) around edge of the copula

4

1

Chitinozoa

Table 2 Chitinozoan biozonation (458–444 Ma) (continued…)

2.1 Chamber Shape The shape of the chamber also varies greatly from being lenticular to cylindrical (Fig. 4(1–7)). A note on the naming of chamber shapes is briefly enumerated below (for terminology see Fig. 4(8 and 9)). However, it must be kept in mind that the collarette (see Fig. 2(1); detailed later in the chapter) is not considered when defining chamber shapes. Major chamber shapes are as follows:

2.1.1 Lenticular The chamber width is significantly larger than the length (D > L), the margin is round, and the base is convex (Fig. 4(1)). Examples: Calpichitina and Fungochitina.

2.1.2 Spherical The chamber width is equal to or close to its length (D  L), margin is inconspicuous, and the base is rounded with a shoulder (or exceptionally evaginated as in Margachitina elegans) (Fig. 4(2)). Examples: Hoegisphaera and Sphaerochitina. 2.1.3 Hemispherical The chamber length is close to half the chamber diameter (L = D/2), base is flat, margin is sharp or blunt, and the shoulder is conspicuous (Fig. 4(3)). Examples: Bulbochitina and Cyathochitina. 2.1.4 Ovoid The length of the chamber is greater than the chamber diameter, but less than three times the

2

General Morphology

Table 3 Chitinozoan biozonation (443–420 Ma) (continued…)

5

6 Table 4 Chitinozoan biozonation (410–359 Ma)

1

Chitinozoa

2

General Morphology

7

Fig. 2 Chitinozoan morphological features, types of vesicle wall surfaces and vesicle shapes. 1–4: Main morphological features of the three principal types of chitinozoan vesicles (modified after Paris 1981); 5–6: Variations in vesicle shapes

diameter (3D > L > D), base is convex to rounded, and the margin and flexure are inconspicuous (Fig. 4(4)). Examples: Desmochitina and

Angochitina, though, more rarely truncated as in Lagenochitina dalbyensis or ogival as in Lagenochitina conifundus.

8

1

Chitinozoa

Fig. 3 Additional morphological features of a chitinozoan showing chamber details including sleeve, operculum, and attachment (modified after Paris 1981; Paris et al. 1999)

2.1.5 Conical With straight, tapering flanks, flat base, and sharp or blunt margin (Fig. 4(5)). Examples: Bursachitina, Euconochitina, and Cyathochitina. 2.1.6 Claviform The chamber length exceeds three times the maximum diameter (L > 3D), base is rounded, margin is inconspicuous, and the shoulder is absent (Fig. 4(6)). Examples: Clavachitina and Laufeldochitina.

2.1.7 Cylindrical The chamber length is several times that of the diameter, flanks are straight and parallel, the base is flat, and the margin is sharp or blunt (Fig. 4 (7)). Example: Rhabdochitina. The vesicle’s oral end (apertural pole) bears the aperture which is usually produced into a neck; the aboral end (toward Apex) is broader and closed (Figs. 2(1–4), and 3). The aperture is occluded by a separate operculum (Figs. 2(3), and 3(1–3)), whose form and position are of

2

General Morphology

9

Fig. 4 Chamber shapes (1– 7) and criteria for chamber measurement (8–9)

great taxonomic importance. The aperture is either situated directly on the chamber (Fig. 2(3)) or at the distal end of a tube-like neck (Fig. 3(3)). The apertural pole (Fig. 2(1–4)) represents the top of the vesicle such that in a chain-like structure, the upper (or last) vesicle possess a free aperture (Fig. 3(6 and 7)). In certain genera, the operculum is deeply recessed within the neck (i.e., the apertural tube) so that adhesion of the adjacent vesicle is achieved by a basal, tubular appendage called the copula (Fig. 3(2–5)).

2.2 Ornamentation and Surface Patterns The junction between the flanks and the bottom of the chamber (the anti-apertural end) is called the margin (=Basal margin; see Fig. 5(1)). Both the shape (Fig. 5(2–5)) and the ornamentation (processes, Fig. 5(1); carina, Fig. 5(6–15); and spines, Fig. 5(16–22)) and surface patterns of the wall (=Sculpture: Fig. 5(1 and 23–27)) are of taxonomic importance for suprageneric and

10

1

Chitinozoa

Fig. 5 Margin, Carina, ornamentation, and sculpture. 1–5: Variability in vesicle margin; 6–15: Variability in Carina; 16–22: Ornamentation of the vesicle wall; 23–27: Surface patterns of the vesicle wall (Sculpture) (modified after Paris 1981; Paris et al. 1999)

generic assignment (see also Paris et al. 1999). The carina (Fig. 5(6–15)) is an important external structure and corresponds to an extension (annular evagination) of the outer layer, perpendicular to the axis of the vesicle and may be located either below, on, or above the margin. It can be thick (as in Laufeldochitina embranous,

Cyathochitina kuckersiana, and Pterochitina perivelata), may extend horizontally (as in Cyathochitina vaurealensis), or flare antiaperturalwards (as in Laufeldochitina). It may also be complete (as in Cyathochitina), perforated, reticulated (as in Sagenachitina and Baltochitina) or laciniated (as in Pogonochitina

2

General Morphology

spinifera). The carina may be associated either with a glabrous or spiny wall and/or apical structures. But the carina does not coexist with processes (=homologous elements; see Fig. 5 (1)). The chitinozoans also exhibits varied ornamentation that includes all kinds of spiny extensions longer than 2 µm, occurring on the vesicle (Fig. 5(1 and 16–22)). They could be simple (Fig. 5(16)), bifurcated or branching spines (Fig. 5(17)), bi- or multi-rooted spines (Fig. 5(18)), anastomosed spines or those connected by a mesh-like structure (Fig. 5(19)), spines in rows (Fig. 5(20)), crowns or crests or randomly distributed on part or all of the vesicle (Fig. 5(21 and 22)). The spiny ornament, which is usually hollow, may coexist with any of the other elements (i.e., carina, and apical structures, except for a glabrous surface). It is of prime importance to distinguish eroded spines (rounded scars) from a truly glabrous surface. Spines, when located on the margin, and forming a crown are then called, processes (Fig. 5(1)). They display the same range of complexity as the spines occurring on the flanks (Fig. 5(1)), but in addition, they may have a spongy or a cell-like texture (as in Plectochitina). The surface patterns (Fig. 5(23–27)) on the chitinozoan wall is also very varied and can be smooth or scabrate, vermiculate (Fig. 5(23)), foveolate (Fig. 5(24)), feltlike (Fig. 5(25)), spongy (Fig. 5(26)), or microgranulous surfaces, including tubercles and cones (Fig. 5(27)). When the granules are 50 µm are termed as acritarchs. But, recently Javaux et al. (2010) recorded well-preserved organic-walled microfossils that were as big as 300 µm from 3.2 Ga-old shallow-marine siliciclastic rocks in the Mesoarchaean (2.8–3.2 Ga) shales and siltstones of the Moodies Group, South Africa.

2.1 Sphaeromorphs and Acanthomorphs Acritarchs are either smooth (sphaeromorphs; Fig. 2(1)) or covered in spines (acanthomorphs; Fig. 2(2)). The sphaeromorphs are the oldest acritarch group (1.8 Ga; Lamb et al. 2009) (see Fig. 2(3)). The unornamented (smooth) and spherical forms are called leiosphaerids. The sphaeromorphs may, at times, bear a variety of surface ornamentation/sculpture such as meshwork, pores, or corrugation. They also display several shapes such as spheroidal, ovoidal (ellipsoidal), and fusiform (spindle-shaped) and range in size from 62 to 216 µm (Lamb et al. 2009). The sphaeromorph walls may be psilate, scabrate, verrucate, rugulate, fossulate, but not truly spinous. The acanthomorphs (Figs. 2(4–12) and 3), on the other hand, are ornamented with spiny protrusions called “Processes” (Fig. 3(1)) that vary in size, shape and distribution along the vesicle surface (Fig. 3). These, at the Cambrian– Ordovician boundary, are remarkably complex and diverse in shape (Fig. 4). Here, it must be mentioned that some palynologists use “sculpture” for elements that are 2. They are called pororate and possess incongruent ectoaperture and endaperture (Fig. 7(28)) as in Betula and Casuarina. Congruent ecto and endospores are called porate. 3.3.17 Tricolpate/Tricolporate/ Triporate Three ectocolpi, three compound apertures or three pores, respectively (Fig. 7(35–40)). Tricolpate (Fig. 7(35 and 36)) have three meridionally placed colpi without pores, transverse furrows or other such modifications. Tricolporate (Figs. 7(37), 8, 9, 10, and 11(38)) have three colpi with pores or other usually equatorial modifications. The Triporate have three equatorial more or less isodiametric germinal apertures (Fig. 7(39 and 40)).

54

3 Pollen and Spores

Fig. 9 Pollen symmetry. The pollen grains or spores are either symmetric (1–4) or asymmetric (5–9) (modified from Erdtman 1943, 1952; Punt et al. 2007). See text for further explanation

3.3.18 Zonocolporate (=Stephanocolporate) These have more than three colpi, meridionally arranged and provided with pores (Fig. 7(43 and 44)). 3.3.19 Zonoporate (=Stephanoporate) These have more than three equatorial, equally spaced pores on the equator (Fig. 7(45 and 46)). Pollen grains with other intermediate types are also noted, and they include:

3.3.20 Heterocolpate These have both simple and compound colpi as in Lythrum, Peplis (Lythraceae) (Fig. 7(50 and 51)). 3.3.21 Synorate or Svnclinorate These have lalongate ora, anastoming latitudinally (Fig. 7(52)), as in Solanum. 3.3.22 Multi Orate These have two or more ora found latitudinally, along the length of the colpus (Fig. 11(53)), as in Viticipremna.

3

Pollen Morphology

55

Fig. 10 Spore size (modified from Chaloner and Sheerin 1981; Traverse 2007). 0.1 mm = 100 lm. See text for further explanation

3.3.23 Porocolpate These have apertures in which colpi alternate with pores around the equator (Fig. 7(54 and 55)), as in Pardoglossum (Boraginaceae).

3.3.25 Colpoidorate These have weakly developed colpi (=Colpoids) but well-developed ora (Fig. 7(57)), as in Alangium villosum.

3.3.24 Colporoidate These have well-developed colpi but weakly developed ora (=Oroids) (Fig. 11(56)) as in Phalline lucida.

3.3.26 Lophate/Fenestrate These have window-like pattern of ridges (=lophae) formed by an outer exine surrounding window-like spaces or depressions. The fenestrate pollen is characterized by the lack of tectum (Fig. 7(58–60)).

56

3 Pollen and Spores

Fig. 11 Sporoderm stratification (1–5) and sculpturing, i.e., exine ornamentation (6–9) (modified from Erdtman 1969; Faegri and Iversen 1964, 1975, 1989; Punt et al. 2007; Traverse 2007). The sporoderm (pollen wall) is stratified and consists of two layers, the outer exine and the inner intine and with further subdivisions of these two. Perine is often used in conjunction with sexine and nexine and often cannot be differentiated from sexine in the fossil material. See text for further explanation

3.4 Shape Shape (Fig. 8) is also a diagnostic character for species identification. But it varies greatly, from species to species, to within one grain type and even within one species. Pollen and spores are described by the shape of their outline, either as non-angular or angular (Fig. 8). The outline or circumference in polar view is called Amb. Based on the ratio of polar axis (PA) and equatorial diameter (ED) (Fig. 8, inset), eight shape classes are noted (see Erdtman 1952). In the equatorial

view, the ratio between the PA and ED, multiplied by 100 gives the indication of the shape such as prolate, prolate–spheroidal, spheroidal, sub-prolate, perprolate, oblate, oblate–spheroidal, sub-oblate, and peroblate (see Fig. 8).

3.5 Symmetry Symmetry with relation to a pollen grain implies similarity of halves on either side of a median line or plane so far as aperture and ornamentation,

3

Pollen Morphology

etc., are concerned. The pollen grains or spores can be either symmetric or asymmetric (Fig. 9). In asymmetric ones, there is no plane of symmetry (as in Berberis darwinii, Papaver argemone, and Myriophyllum alterniflorum). These may be with fixed shape, called fixiform or without any definite shape called non-fixiform. Asymmetric pollen and spores are very rare. The symmetric ones can be either radially symmetrical (radiosymmetric; Fig. 9(1–4)) or bilaterally symmetrical, i.e., having a single plane of symmetry (Fig. 9(5–9)). In radially symmetrical grains, any plane including the polar axis, produces identical halves (Fig. 9(1–4)). Hence, such grains possess more than two vertical planes of symmetry (as in Centaurea); one horizontal and two or more vertical. All the planes are of equal length. In radially symmetrical heteropolar spores, there is no horizontal plane of symmetry, but two or more vertical planes of symmetry (as in Osmunda regalis, Ophioglossum vulgatum, and Pteridium aquilinum) (Fig. 9(4)). Most pollen and spores are symmetrical. The bilateral isopolar spores (Fig. 9(7 and 8)) exhibit two vertical planes and one horizontal plane of symmetry. All the planes are not of equal length (as in Rungia grandis). In bilateral heteropolar spores (Fig. 9(9)), there exist two vertical planes of symmetry. The planes are unequal in length and intersect each other at right angles (as in Ephemerum serratum, Picea abies, and Cycas revoluta).

3.6 Size Size, like shape, varies greatly (Fig. 10). The smallest is about 5  2.4 µm (Myosotis palustris) whereas some are large, >200 µm in diameter, as in Boraginaceae, Curcurbitaceae, Nyctaginaceae, and Orectanthe ptaritepuiane (Abolbodaceae). Microspore is a term used to include all spores 0.5 µm, if any. The different pollen size classes, based on the size expressed as the length of the longest axis, are given in Fig. 10 (see also Erdtman 1945).

4

Sporoderm Stratification

The Sporoderm (pollen wall) in mature pollen (Fig. 11(1)) is stratified and consists of two layers, the outer exine and the inner intine (Fig. 11 (2–5)). Perine is the outermost layer of the sporoderm that is mainly present in spores of ferns and mosses in contact with the exine (Fig. 11(3)), and is not always acetolysis resistant. Perine is often used in conjunction with sexine and nexine and often cannot be differentiated from sexine in the fossil material (see Erdtman 1943; Punt et al. 2007). Exine is the outer layer of the wall of a palynomorph (Fig. 11(4 and 5)). It is composed largely of sporopollenin, a chemically inert biological polymer. Exine covers the entire pollen surface except the apertures where it is either absent or is very much reduced. Exine is divided into two layers, an outer sculptured sexine and an inner unsculptured nexine (Fig. 11(4 and 5)). Sexine, in turn, is also made up of two layers, the outer, ectosexine and the inner, endosexine (Fig. 11(5)). Endosexine consists of columella, baculum, and void spaces separating the bacula from each other (Fig. 11(4)). The columella (pl. columellae, adj. columellate) is a column-like element of sexine that supports the tectum at the top. A baculum is also a sexine element, which is a slim, cylindrical rod-like structure and stands on the nexine. Each baculum is more than 1 lm in length and less than this, in diameter. Bacula are straight and often end abruptly (Fig. 11(4)). The sexine is made up of a set of radially directed rods supporting a roof-like structure on the periphery of a pollen grain called tectum or tegillum, which may be partially perforated or completely absent (Fig. 11(4)); when absent, it is

58

called atectate or intectate (Fig. 13(1)). The rod-like elements of the ectexine/sexine supporting a tectum are called columella/columellae (Fig. 11(4 and 5)). Intine is the innermost layer bordering the surface of the cytoplasm and underlies the exine (Fritzsche 1837). It is soft, fragile, and pliable and remains tightly attached to the plasma membrane (Fig. 11(2, 4 and 5)). It is composed of cellulose and pectates and is normally absent in fossil sporomorphs. Intine is not acetolysis resistant, and hence, is often absent in conventionally prepared fossil palynological material. The thickness of intine is related to that of exine. In the place where the exine gets thinner, the layer of intine becomes thicker. Hence, thickened portions of intine occur under pores.

4.1 Exine Ornamentation There are two different types of exine ornamentation, sculpturing (Fig. 11(6–9)) and structure or texture (Fig. 13). The structure comprises of all the internal (infratectal) baculae (singular = baculum; see Fig. 11(4)) with various form and arrangements (Fig. 12(1–26)). A baculum is a free-standing element of sculpturing, but a columella is part of the structure (Punt et al. 2007) (see Fig. 11(4)). All ektexine (also referred to as Ectexine) (Fig. 11(4)) characters are structural features, whereas sculpturing comprises all external (supratectal) geometric features (Fig. 12) without reference to their internal construction. Tectum may be smooth i.e., psilate (see Fig. 12 (1)) or with processes of various kind like spinules, spines, pila, verruca, gemma, clava, granules, etc. (see Fig. 12(1)). Tectum provided with the processes are referred to their respective terminology (see Fig. 12(1)). For example, tectum with spinules is referred to as spinulate, with spines called echinate, with pila called pilate, with verruca called verrucate, with gemma called gemmate, with clava called clavate, with granules called granulate, etc. (see Fig. 12(1)). The exine ornamentation can be diagnostic of specific pollen types. Some of these are briefly enumerated below and illustrated in Fig. 12.

3 Pollen and Spores

4.1.1 Fossulate These are elongated, irregular grooves on the surface (Fig. 12(1)). 4.1.2 Clavate These are club-shaped elements higher than 1 lm (Fig. 12(1)). 4.1.3 Perforate These are holes 1 lm in length; height is greater than the basal diameter (Fig. 12(10 and 11)). 4.1.8 Verrucate These are wart-like knobs or elevations >1 lm wide, broader than its height and not constricted at the base (Fig. 12(12 and 13)). 4.1.9 Clavate These are club-shaped elements, higher than 1 lm, with diameter smaller than its height, and thicker at the apex than at the base (Fig. 12(14 and 15)). 4.1.10 Echinate/Spinate These have ornamentation with spines >1 lm where the height is at least twice the basal diameter (Fig. 12(16)).

4

Sporoderm Stratification

59

Fig. 12 Sporoderm structure and various modifications (modified from Tschudy 1969). See text for further explanation

60

4.1.11 Rugulate These are elongated elements, >1 lm long, arranged in an irregular pattern that is intermediate between striate and reticulate (Fig. 12(18 and 19)). 4.1.12 Reticulate/Reticulum These have a network-like pattern consisting of lumina or other spaces wider than 1 lm and bordered by elements narrower than the lumina (Fig. 12(20 and 21)). The lumina are pits between the elevations of a reticulate sculptural pattern (i.e., enclosed areas). Lumina can either be rounded or polygonal in shape. 4.1.13 Striate These are fine, elongated, parallel elements (ridges) separated by grooves (Fig. 12(22 and 23)). 4.1.14 Faveolate These are small (up to 2 µm), rounded depressions that are more or less rounded in surface view and widely spaced so as not to form a reticulum (Fig. 12(24 and 25)). 4.1.15 Cicatricose These are marked with long scars (more or less parallel ridges) (Fig. 12(26)). Nexine is the non-sculptured part of exine and occurs below the sexine (Fig. 11(2, 4, and 5)). Two subdivisions are noted, ectonexine and endonexine on the basis of thickness and refractive zone (Fig. 11(5)). Ectonexine is the peripheral layer of nexine, exhibits more or less thick and “not very refractive zone.” Endonexine is the inner layer of nexine, more or less thin and exhibits more refractive zone. Based on staining characteristics, two layers are noted in nexine, ectexine and endexine (Erdtman 1969). Ectexine stains positively with basic fuchsin while endexine remains relatively unstained. Ectexine, the outer part of the exine also has higher electron density in conventional prepared TEM sections and includes the foot layer, if present (Fig. 11(4 and 5)). Endexine, the inner part of the exine, has a lower electron density in conventionally prepared TEM sections (but this

3 Pollen and Spores

assertion is hotly debated); it does not include the nexine which is considered part of the ectexine (Fig. 11(4 and 5)).

5

Earliest Plants

Plant megafossils are rare, as they lack fossilizable tissues. However, there is a large microfossil record of dispersed spores (cryptospores) preserved (see Steemans 2000; Steemans et al. 2000). Cryptospores are spore-like dispersed remains of subaerial (and possibly, semi-aquatic) plants that lack the haptotypic features (trilete marks) and characterize vascular (tracheid-bearing) plant spores (although rare non-vascular plants also have spores with trilete mark). They are alete (i.e., lacking a well-defined aperture), and relatively thick-walled pseudomorphs that occur in unusual configuration (monads, permanently united dyads or tetrads) (Richardson et al. 1984; Strother 1991; Richardson 1996; Steemans 1999, 2000; Strother 2000; Wellman and Gray 2000; Strother and Beck 2000). The cryptospores are the characteristic component of non-marine palynomorph assemblages from the Palaeozoic strata of pre-Devonian age. Because macroscopic and mesoscopic plant remains do not occur prior to the Homerian (430.5–427.4 Ma), and cryptospores are used as a proxy for terrestrial plants during the Early Paleozoic. The timing and extent of the first terrestrial (subaerial) plant cover is still a matter of much speculation, but the cryptospore record indicates that plants of a bryophyte grade were available to colonize surface habitats from the Middle Cambrian onwards. A diverse cryptospore assemblage of five genera of naked and envelope-enclosed monads and tetrads are the earliest palynological evidence dating back to earliest Ordovician (*473– 471 Ma) from Argentina (eastern Gondwana) (see Rubinstein et al. 2010). These are: Chomotriletes? sp., Gneudnaspora (Laevolancis) divellomedia or Laevolancis chibrikovae, Sphaerasacus glabellus and Tetrahedraletes cf. medinensis (see Rubinstein et al. 2010).

5

Earliest Plants

Fig. 13 Representative species diagrams

61

62

Fig. 14 Representative species diagrams (continued…)

3 Pollen and Spores

5

Earliest Plants

63

Fig. 15 Representative species diagrams (continued…)

Previously, the earliest embryophyte traces were the late Darriwilian (Middle Ordovician; *463– 461 Ma) cryptospores from Saudi Arabia and from the Czech Republic (western Gondwana) (Vavrdová 1990; Strother et al. 1996). The analysis of wall ultrastructure of slightly younger cryptospores from Oman indicated that they were produced by early liverworts (Wellman et al. 2003). These evidences indicate that the embryophytes first evolved in the Gondwana and that the terrestrialization of plants might have begun

in the eastern part of Gondwana (see Rubinstein et al. 2010). The Argentinean discovery, the earliest evidence of plants on land, also suggests an earlier origin of embryophytes, latest Cambrian-Early Ordovician (488–472 Ma) or even Cambrian (*541–488 Ma) (see Strother and Beck 2000). The vascular plants are considered to have originated and adaptively radiated from the Early Silurian on the basis of major changes in spore assemblages (from cryptospore to hilate/trilete spore dominated) and the

64

appearance of vascular plant megafossils (see Steemans et al. 2009). Some representative species are illustrated with their respective time ranges (Figs. 13, 14 and 15).

References Chaloner, W. G., & Sheerin, A. (1981). The evolution of reproductive strategies in early land plants. In G. G. E. Scudder, & J. L. Reveal (Eds.), Evolution today. Proceedings of the Second International Congress of Systematic and Evolutionary Biology, 93–100. Erdtman, G. (1943). An introduction to pollen analysis (p. 239). Waltham, MA: Chronica Botanica Company. Erdtman, G. (1945). Pollen morphology and plant taxonomy. Labiatae, Verbenaceae and Avicenniaceae. Sven Bot Tidskr, 39, 279–285. Erdtman, G. (1947). Suggestions for classification of fossil and recent pollen grains and spores. Svensk Botanisk Tidskrift, 41, 104–114. Erdtman, G. (1952). Pollen morphology and plant taxonomy. Angiosperms (p. 539). Stockholm: Almqvist and Wiksell. Erdtman, G. (1969). Handbook of palynology—An introduction to the study of pollen grains and spores (p. 486). Copenhagen: Munksgaard. Faegri, K., & Iversen, J. (1964). Textbook of pollen analysis (2nd ed., 237 pp). Copenhagen: Munksgaard. Faegri, K., & Iversen, J. (1975). Textbook of pollen analysis (3rd ed.). New York: Hafner. Faegri, K., & Iversen, J. (1989). Textbook of pollen analysis (4th ed., 328 pp). Chichester: John Wiley & Sons, Inc. Fritzsche, J. (1837). Über den Pollen. Mem Sav Etrang Acad, 3: St. Petersburg, 649–769. Grebe, H. (1971). A recommended terminology and descriptive method for spores. Comm. Intern. Microflore Palaeozoique, 4: Les Spores, 1, 7–34. Halbritter, A. H., Halbritter, H., Ulrich, S., Grímsson, F., Weber, M., Zetter, R., et al. (2018). Illustrated pollen terminology (486 p). Berlin: Springer. Harris, W. F. (1955). A manual of the spores of New Zealand Pteridophyta. A discussion of spore morphology and dispersal with reference to the identification of the spores in surface samples and as microfossils. New Zealand Department of Scientific and Industrial Research Bulletin, 116, 1–186. Hesse, M., Halbritter, M., Zetter, R., Weber, M., Buchner, R., Frosch-Radivo, A., & Ulirch, S. (2009). Pollen terminology: An illustrated handbook. Vienna: Springer. Kremp, G. O. W. (1968). Morphologic encyclopedia of palynology (2nd ed., 263 pp). Tucson: University of Arizona Press.

3 Pollen and Spores Potonié, R. (1934). I. Zur Morphologie der fossilen Pollen und Sporen. Arb. Inst. Paläobotanik Petrographie Brennsteine, 4, 5–24. Potonié, R., & Kremp, G. O. W. (1955). Die Sporae dispersae des Ruhrkarbons, ihre Morphographie und Stratigraphie mit Ausblicken auf Arten anderer Gebiete und Zeitabschnitte. Palaeontographica Abteilung B, 98, 1–136. Punt, W., Blackmore, S., Nilsson, S., & Le Thomas, A. (1994). Glossary of pollen and spore terminology. LPP Contributions Series 1, LPP Foundation, Laboratory of Palaeobotany and Palynology, University of Utrecht, Utrecht. Punt, W., Hoen, P. P., Blackmore, S., Nilsson, S., & Le Thomas, A. (2007). Glossary of pollen and spore terminology. Review of Palaeobotany and Palynology, 143, 1–81. Richardson, J. B. (1996). Taxonomy and classification of some new Early Devonian cryptospores from England. Special Papers in Palaeontology, 55, 7–40. Richardson, J. B., Ford, J. H., & Parker, F. (1984). Miospores, correlation and age of some Scottish Lower Old Red Sandstone sediments from the Strathmore region (Fife and Angus). Journal of Micropalaeontology, 3(2), 109–124. Rubinstein, C. V., Gerrienne, P., de la Puente, G. S., Astini, R. A., & Steemans, P. (2010). Early Middle Ordovician evidence for land plants in Argentina (eastern Gondwana). New Phytologist, 188, 365–369. Steemans, P., (1999). Paléodiversification des spores et des cryptospores de l'Ordovicien au Dévonien inférieur. Géobios, 32(2), 341–352. Steemans, P. (2000). Miospore evolution from the Ordovician to the Silurian. Review of Palaeobotany and Palynology, 113, 189–196. Steemans, P., Higgs, K. T., & Wellman, C. H. (2000). Cryptospores and trilete spores from the Llandovery, Nuayyim-2 Borehole, Saudi Arabia. In S. Al-Hajri & B. Owens (Eds.), Stratigraphic palynology of the Palaeozoic of Saudi Arabia (Special Vol. 1, pp. 92– 115). Manama, Bahrain: GeoArabia. Steemans, P., Le Hérissé A., Melvin, J., Miller, M. A., Paris, F., Verniers, J., & Wellman, C. H. (2009). Origin and radiation of the earliest vascular land plants. Science, 324, 353. Strother, P. K. (1991). A classification schema for the Cryptospores. Palynology, 15, 219–236. Strother, P. K. (2000). Cryptospores: The origin and early evolution of the terrestrial flora. In R. A. Gastaldo & W. A. DiMichele (Eds.), Phanerozoic terrestrial ecosystems (Vol. 6, pp. 3–19). The Paleontological Society Papers. Strother, P. K., Al-Hajri, S., & Traverse, A. (1996). New evidence for land plants from the lower Middle Ordovician of Saudi Arabia. Geology, 24, 55–59. Strother, P. K., & Beck, J. H. (2000). Spore-like microfossils from Middle Cambrian strata: Expanding the meaning of the term cryptospore. In M. M. Harley, C. M. Morton, & S. Blackmore (Eds.), Pollen and

References spores: Morphology and biology (pp. 413–424). Kew, UK: Royal Botanic Gardens. Traverse, A. (2007). Paleopalynology. In N. L. Landman & D. S. Jones (Eds.), Topics in geobiology (2 ed., pp. 1–813). Dordrecht, The Netherlands: Springer. Tschudy, R. H. (1969). The plant kingdom and its palynological representation. In Aspects of palynology (518 pp). Wiley-Interscience. Vavrdová, M. (1990). Early Ordovician acritarchs from the locality Myto near Rokycany (late Arenig,

65 Czechoslovakia). Casopis pro Mineralogii a Geologii, 35, 239–250. Wellman, C. H., & Gray, J. (2000). The microfossil record of early land plants. Philosophical Transactions of the Royal Society of London, 355B, 717–732. Wellman, C. H., Osterloff, P. L., & Mohiuddin, U. (2003). Fragments of the earliest land plants. Nature, 425, 282–285.

4

Dinoflagellates

1

Introduction

Dinoflagellates (=whirling whips) are ubiquitous unicellular organisms of the aquatic ecosystems and second only to diatoms as marine primary producers. Of the *2000 living species, 85% are marine and about 11% freshwater forms (Taylor et al. 2008). Almost half of the total species are either photosynthetic or exclusively heterotrophic (Gaines and Elbrächter 1987), hence, making them an important member of both marine and freshwater phytoplankton and zooplankton ecosystems. Additionally, together with diatoms and coccolithophores (Calcareous nannofossils), they are a major fraction of the eukaryotic phytoplanktons of the world’s oceans (Delwiche 2007). The earliest fossil dinoflagellate cysts are known from the Ladinian of the Middle Triassic (Riding et al. 2010). The dinoflagellates are excellent index fossils due to their restricted stratigraphic ranges and large spatial distributions (Powell 1992; Stover et al. 1996; Poulsen and Riding 2003; Traverse 2007; Riding 2012) (see Tables 1, 2, 3, 4, 5, 6, 7, 8, and 9). Traditionally, four classes constitute the algal Division Pyrrhophyta—Ebriophyceae, Ellobiophyceae, Desmophyceae, and Dinophyceae

(Fig. 1(1)). Class Dinophyceae is divided into three orders (and known only from fossil record)—Dinophysiales, Gymnodiniales, and Peridiniales (=the thecate dinoflagellate) (see Fig. 1(2–4), respectively) and are an important constituent of the oceanic phytoplankton scene, since the mid-Mesozoic. They are also one of the most primitive eukaryotes and are intermediates between prokaryotes and eukaryotes. Around 4500 species assigned to about 550 genera are known, and of them, three quarters of the genera and half of the species are fossil. Most dinocysts (the resting cysts that are resistant and occur in fossil records, as opposed to the unmineralized motile cells) are between 25 and 250 µm in diameter; they may be spherical to ellipsoid to elongate in shape. The dinoflagellates are best known for causing harmful algal blooms wherein the dinoflagellates make up almost 80% of the toxic phytoplankton species (Cembella 2003). These “red tides” kill fish and/or shellfish either directly, because of the toxins they produce (dinoxanthin and peridinin), or due to the effects caused by the large numbers of dinoflagellate cells that clog animal gills, and deplete oxygen (Smayda 1997); the dinoflagellate toxins are also among the most potent known biotoxins.

© Springer Nature India Private Limited 2020 S. Jain, Fundamentals of Invertebrate Palaeontology, Springer Geology, https://doi.org/10.1007/978-81-322-3962-8_4

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68 Table 1 Stratigraphic occurrences of important marker taxa (203–175 Ma)

4

Dinoflagellates

Table 2 Stratigraphic occurrences of important marker taxa (173–164 Ma)

1 Introduction 69

Table 3 Stratigraphic occurrences of important marker taxa (163–146 Ma)

70 4 Dinoflagellates

Table 4 Stratigraphic occurrences of important marker taxa (145–127 Ma)

1 Introduction 71

72 Table 5 Stratigraphic occurrences of important marker taxa (126–101 Ma)

4

Dinoflagellates

1

Introduction

Table 6 Stratigraphic occurrences of important marker taxa (100–67 Ma)

73

74

4

Dinoflagellates

Table 7 Stratigraphic occurrences of important marker taxa (64–42 Ma)

2

General Morphology

The dinoflagellates have large vacuoles (pusules; Fig. 1(3)) that are connected to the exterior by a delicate canal. The protoplast possesses two

flagella (longitudinal and transverse) arising from flagellar pores in the cell wall, and whose location is important in classification (Fig. 1(5–7)). The whip-like longitudinal flagellum is directed backwards along a longitudinal furrow (or depression) called the sulcus; it is a groove in the

2

General Morphology

75

Table 8 Stratigraphic occurrences of important marker taxa (40–21 Ma)

ventral surface (Fig. 1(5–7)). The side bearing the sulcus is ventral (Fig. 1(6)), while the opposite side is dorsal (Fig. 1(7)). Many cells and cysts are dorsoventrally compressed so that these two views are the ones usually illustrated (as in Genus Cyclonephelium). The transverse flagellum that encircles the cell (once or several times) in a transverse or spiral groove (=transverse furrow or girdle; Fig. 1(4)) is called the cingulum (Fig. 1(5)). If it encircles several times, the

cingulum is then twisted around the cell and is defined as Torsion (see Fig. 2). The sulcus and cingulum intersect near the mid-ventral point (Fig. 1(6)). The cingulum divides the cell into an anterior area called the episome (also called epitheca or epicone), and a posterior area, the hyposome (Fig. 1(6)). The sulcus lies wholly or partially in the hyposome (also called hypotheca or hypocone) (Fig. 1(5 and 6)). The sulcus extends in a posterior direction and may

76

4

Dinoflagellates

Table 9 Stratigraphic occurrences of important marker taxa (22 Ma – Present)

terminate in a depression flanked by one or two antapical horns (Fig. 1(4, 6, and 7)). The anterior or apical end is often rounded, pointed, or produced into an apical horn (Fig. 1(7)). The anterior portion of the episome is called the apex (Fig. 1(5)). The posterior portion (excluding spines and similar structures) of the hyposome is called the antapex (Fig. 1(5–7)). Around the epitheca, the apical and precingular series occur (Figs. 3 and 4). In the

cingulum, lies the cingular series while the postcingular and antapical series occur on the hypotheca (Figs. 3 and 4). Additional anterior and posterior intercalary plates may also develop at sites between the series, and the sulcus bears small sulcal plates that are of taxonomic importance. The Intercalaries (the secondary series of plates) never touch the apex, antapex, or cingulum. The series and number of plates can be expressed as the plate formula, using Kofoid’s

2

General Morphology

77

Table 10 Alphanumeric system of plate designation (after Kofoid 1907, 1909) (see also Figs. 3 and 4) Vegetative stage

Encysted stage

Location

Symbol

Plate series

Paraplate series

Apical

Apical

Touching the apex but not the cingulum or paracingulum

Anterior intercalary

Anterior intercalary

Between the apicals and precingulars but not touching the apex or cingulum (paracingulum); can be ventrally or dorsally located

Precingular

Precingular

Cingular

Individual plate or paraplate Position

Symbol

Second apical

2′

a

Third anterior intercalary

3a

Immediately anterior to the cingulum or paracingulum and not touching the apex

″

Fifth precingular

5″

Paracingular

Cingulum or

c or

Fourth cingular

4c

Or girdle

Paracingulum

pc

Or paracingular

4pc

Postcingular

Postcingular

Immediately posterior to the cingulum or paracingulum and not touching the antapex

″′

Sixth postcingular

6″′

Posterior, intercalary

Posterior, intercalary

Between the postcingulars and antapical (s) and not touching the cingulum (paracingulum) or antapex; usually adjacent to the sulcus or parasulcus

p

First posterior intercalary

1p

Antapical

Antapical

Touching the antapex but not the cingulum or paracingulum

″″

First antapical

1″

Sulcal

Parasulcal

Occupying a position on the

s

Anterior sulcal

ls

Sulcus or parasulcus

ps

Parasulcal

lps

alphanumeric system (Table 1; Figs. 3 and 4). Adjacent plates are firmly cemented together along their margins where they overlap in a tile-like fashion. Growth occurs in the sutural areas between plates, in the form of intervening bands, called the Intercalary bands (Fig. 3). A series of articulated plates (composed of cellulose or some other polysaccharide microfibrils) makes the theca (alternatively also called Amphiesma, Cell covering, or Cell wall); the plate number and position constitutes the Tabulation (i.e., counting the plates in a specific designated series) (Figs. 3 and 4). Their number and position are of taxonomic importance

(Figs. 3 and 4). This nomenclature is best exemplified by the Peridiniales (Fig. 3(1–5)) as first laid out by Kofoid (1907, 1909). In Peridiniales, the five-plate series are found to encircle each cell, and each plate is numbered in a counterclockwise direction. From apex to antapex, these include apical (′), anterior intercalary (a), and precingular series (″) of the epitheca, the cingular series (c) composing the cingulum, and the postcingular (‴), posterior intercalary (p) and antapical series (″″) of the hypotheca (Fig. 3(1– 4)). The primary series of plates include—apicals, precingulars, cingulars, postcingulars, antapicals and sulcals (see Table 10; see also

78

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Dinoflagellates

Fig. 1 Characteristics of the Dinophyceae. 1: Broad classification of dinoflagellates; 2: Order Dinophysiales (ventral view of Dinophysis collaris Kofoid and Michener); 3: Order Gymnodiniales (Gymnodinium); 4: Theca of Peridinium leonis Pavillard; 5: Gymnodiniale, showing an extant “Naked” dinoflagellate (a gymnodinioid stage); 6: General terminology for hypo- and epitheca (modified from Haq and Boersma 1998)

2

General Morphology

79

Fig. 2 Types of cingulum (modified from Sarjeant 1974)

Figs. 3 and 4). Each plate series has a superscript designation or a letter. For example, 3′ means that there are three apical (′) plates. More recently, cingular (c) and sulcal (s) plate series have been added to the plate formula as well as components of the APC, i.e., Po, cp, and X, if they occur. Thus, the plate formula is the combined tabulations for the plate series—Po, 4′, 0a, 6″, 8c, 5 s, 5″, lp, 3″″. A plate formula is generally stable within a genus; however, a range in number for a specific series can occur due to splitting of plates or other factors.

2.1 Cyst Types Cyst lengths are between 15 and 500 l, but generally, they range between 60 and 120 l. The presence or absence of processes enables to recognize four major types of cysts, proximate, chorate, cavate, and proximochorate (Fig. 5). Proximate cysts are devoid of processes, and the shape of the cyst closely approaches that of the theca; it probably formed in close contact with the theca (Fig. 5(1 and 2)). The tabulation, cingulum, and sulcus are all reflected in the surface sculpture of a proximate cyst (Fig. 5(2)). The

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Dinoflagellates

Fig. 3 1–4: Tabulation and plate symbols in Peridinium leonis Pavillard (4′, 3a, 7″, 5″ ′ 2″ ″). The notation indicates four apical plates, three anterior intercalary plates, seven precingular plates, five postcingular plates, and two antapical plates (modified after Lebour (1925). 5: Plate shape variations. a: Rhombic apical plate (1′) and the pattern of its relationship with bordering plates in Peridinium; a1: Orthoperidinium (ortho); a2: Metaperidinium (meta); a3: Paraperidinium (para), b: The second anterior intercalary plate (2a) in the various sections of Orthoperidinium and Metaperidinium, b1 and b2, penta; b3, hexa; b4, quadra (modified after Graham 1942); 6 and 7: Wetzeliella reticulata Williams and Downie (Early Eocene), showing the “peridinioid” paratabulation of the genus; 6: Ventral view; 7: Dorsal view (modified after Evitt 1969)

2

General Morphology

81

Fig. 4 1–2: Theca of Gonyaulax spinifera (Claparede and Lachmann) Diesing, showing tabulation (4″, 6″, ?6c, 6′″ ′, 1″ ″, Ip); 1: Ventral view; 2: Lateral view; c = cingular; p = posterior intercalary; (modified after Wall and Dale, 1970); 3–8: Ceratium sp., showing tabulation of the theca (4′, 6″, 5, and 6c, 6″ ′, Ip, 1 ″ ″); 3: Apical view; 4: Ventral view (with an offset sulcus); 5: Antapical view; 6: Right lateral view; Dorsal view; 8: Left lateral view. For details on plate notation, see Fig. 2

chorate cysts (Fig. 5(3 and 4)) possess a main body bearing strongly developed ornamentation or processes (see also Fig. 6), and best noted in

Hystrichosphaeridium (Fig. 6(1 and 2)). chorate cysts usually exhibit no traces of a reflected cingulum or sulcus. The inner and outer bodies in

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Fig. 5 Cyst stages. 1 and 2: Proximate cyst; 1: Peridinium (axial section); 2: Gonyaulacysta (1 and 2: modified after Sarjeant 1974); 3 and 4: Chorate cyst; 3: Gonyaulax with detail of wall (axial section) (modified after Sarjeant 1974); 4: Hystrichosphaeridium (modified after Sarjeant 1974); 5 and 6: Cavate cyst of Deflandrea; 5: Axial section; 7: Proximochorate cyst of Spiniferites (modified after Evitt 1969)

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Fig. 6 1–2: Paratabulation of a chorate cyst, Hystrichosphaeridium tubiferum (Ehrenberg) Deflandre showing the number and position of intratabular processes. 1: Upper surface showing apical tetratabular archeopyle (shaded), precingular processes (1”, etc.) and paracingular processes (pc); 2: Lower surface showing postcingular processes (1” “, etc.), parasulcal processes (ps), single antapical process (1” “), and posterior intercalary processes (p) (modified from Haq and Boersma 1998); 3-6: Process types in chorate dinocysts; 3: Spiniferites ramosus (Ehrenberg), Dorsal view; 4: Oligosphaeridium complex (White) with one intratabular process per paraplate; 5: Hystrichokolpoma eisenacki Williams and Downie with process differentiation; 6: Diphyes colligerum (Deflandre and Cookson) with enlarged antapical process (black)

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Fig. 7 Cardinal positions from which horns originate in a dinocyst; the maximum is 5 (see text for explanation)

a cavate cyst (Fig. 5(5 and 6)) are only in limited contact with each other and have an intervening space between them. This group includes many cysts of the peridinioid type such as Deflandrea (Fig. 5(6)). The cyst wall (called Phragma) is built of organic material and is resistant to bacterial decay. If the autocyst has a single layer, its wall is called an autophragm. A two-layered cyst with connections between the walls has an inner layer, the autophragm, and an ectophragm, and this condition is termed as holocavate. If the two layers are not connected, the cyst is known as cavate and the inner layer is called the endophragm, and the outer layer, the periphragm, which are partially separated, usually at the poles (Fig. 5(5)). The cavities thus formed (pericoels) promote buoyancy in the cyst (Fig. 5(5)). Another cyst type, an intermediate between

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proximate and chorate, is the proximochorate and is characterized by an elaborate ornamentation (Fig. 5(7)). In this type, the tips of the processes are joined by thin, filamentous trabeculae, thus, giving the impression of an additional layer. Some cysts have a smooth surface, while others possess ornamentation that can be either of minor elements such as granules or of major elements like horns, septa or processes (see Figs. 5 and 7). The horns may be apical, antapical, or lateral (Fig. 7); these are useful criteria for establishing the orientation of a dinocyst. A dinocyst never has more horns than its corresponding thecate stage and in both, the maximum is five. The horns can be over 100 µm in length but are generally less than 50 µm. The processes are essentially columnar or spine-like (Fig. 5(3)), whereas septa are membraneous, linear projections arising perpendicularly from the outer wall layer. Processes may be located on or within paraplate boundaries. Process complexes are processes on individual paraplates that are united proximally, distally, or along their length and can be plate centered or form groups (Fig. 8). The ornament can be tabular (sutural) if it defines plate boundaries, or intertabular if it defines the central parts of plates (Fig. 8). Processes that are situated at the intersection of paraplate boundaries are called Gonal and those along boundaries are called Intergonal (Fig. 8(13)). The processes of a dinocyst may be either similar (see Fig. 6(1 and 2)) or they may be differentiated (see Fig. 6(5)); a particular paraplate series is often characterized by a diagnostic type of process. In other taxa, some of the paraplates, commonly the cingular, are devoid of processes (Fig. 6(4)). The preferred orientation of septa and processes often permits one to determine paratahulation in a dinocyst. Process arrangements, shapes, and terminations are important morphologic features in generic and specific classification.

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General Morphology

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Fig. 8 1–6: Intratabular process complexes; 1: Annulate; 2: Soleate; 3: Arcuate; 4: Linear; 5: Simulate’ 6: Simulate (adjacent processes joined); 7–14: Surface ornament; 7–8: General terminology (see text for explanation); 9: Non-tubular; 10: Paratubular; 11: Peritubular; 12: Parasutural septae; 13: Gonal and Intragonal processes; 14: Intratabular process group (modified after Evitt 1969)

2.2 Archeopyle The function of the cyst is demonstrated by the presence of an escape hole, called an archaeopyle (from the Greek words arche: old and pyle: gate or orifice) (Fig. 9). This regular-shaped opening is called the operculum that results from the complete or partial removal of one or more than one paraplate. If the archeopyle is formed from the rupture of the “suture” between adjacent paraplates, then, in such cases the operculum is absent. The plate removal is normally from the

apical series, the precingular series, an anterior intercalary plate or a combination of these. Hence, this rupturing of plates (=archeopyle) may occur along the girdle, along the line of sutures between the apical and precingular series of plates, or more commonly by the release of a single plate of the epitheca. The form and position of the archeopyle is constant within a genus, a genetically determined feature and constant in all known species. There are of three major types of archeopyles—apical, intercalary, and precingular (Fig. 9) (for details see Sarjeant 1974).

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Fig. 9 Archeophyle arrangements. 1: Archeophyle terminology; 2–3 and 6: Apical archeophyle; 2: Dorsal view; 3: Apical view; 4 and 7–9: Intercalary archeophyle; 5 and 10–13: Precingular archeophyle; 14–17: Combination archeophyle (modified after Evitt 1969)

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Geological History

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Fig. 10 Dinoflagellate species diversity, major radiation, and recovery patterns

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Geological History

The earliest record of an equivocal peridinoid cyst is Arpylorus antiquus Calandra from the Silurian (Tunisia). It has been interpreted as possessing tabulation, a cingulum and a precingular archeopyle. However, this has been strongly contested (see Herisse Le et al. 2012) who do not consider A. antiquus as a dinoflagellate. According to these authors, based on biomarker record, the dinoflagellates may have older Paleozoic or even Proterozoic ancestors; the dinoflagellate tabulation evolved only in the early Mesozoic. The main dinoflagellate radiation began in the Mid- to Late Triassic (Fig. 10) with the appearance of genera such as Suessia or the Rhaetogonyaulax from the Rhaetian (Late Triassic). Proximate cysts were common throughout the

Jurassic (Gonyaulacysta jurassica), although chorate and proximochorate cyst types had appeared by the Middle Jurassic. Many Cretaceous forms are chorate (such as Hystrichosphaeridium) or proximochorate (such as Spiniferites ramosus), and it was around this time that the greatest diversity of dinoflagellate cysts was reached (Fig. 10). The cavate peridinoid dinoflagellate cysts began to flourish in Aptian– Albian (Deflandrea and Wetzeliella) and dominated many Tertiary assemblages until the Oligocene, but almost died out in the Pliocene. Proximate and chorate dinoflagellate cysts with complex processes occur in the Eocene and Oligocene, but simpler forms have prevailed since then. Dinoflagellate cysts first appeared in freshwater sediments during the Tertiary. The representative dinoflagellate species are given in Figs. 11, 12, 13, and 14.

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Fig. 11 Some representative chorate dinoflagellate species

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Geological History

Fig. 12 Some representative dinoflagellate species (continued…)

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Fig. 13 Some representative dinoflagellate species (continued…)

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Geological History

Fig. 14 Some representative dinoflagellate species

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References Cembella A. D. (2003). Chemical ecology of eukaryotic microalgae in marine ecosystems. Phycologia, 42, 420–447. Delwiche, C. F. (2007). The origin and evolution of dinoflagellates. In P. G. Falkowski & A. H. Knoll (Eds.), Evolution of primary producers in the sea (pp. 191–205). Burlington, VT: Academic Press. Evitt, W. R. (1969). Dinoflagellates and other organisms in palynological preparations. In R. H. Tschundy & R. A. Scott (Eds.), Aspects of palynology (pp. 439–481). New York, NY: Wiley Interscience. Gaines, G., & Elbrächter, M. (1987). Heterotrophic nutrition. In F. J. R. Taylor (Ed.), The biology of dinoflagellates (pp. 224–268). Blackwell: Oxford. Haq, B. U., & Boersma, A. (1998). Introduction to marine micropaleontology (2nd ed., 376 pp). Elsevier. Herisse Le, A., Masure, E., Javaux, E. J., & Marshall, C. P. (2012). The end of a myth: Arpylorus antiquus paleozoic dinoflagellate cyst. Palaios, 27, 414–423. Kofoid, C. A. (1907). The plates of Ceratium with a note on the unity of the genus. Zoologischer Anzeiger, 32, 177–183. Kofoid, C. A. (1909). On Peridinium stecni Jorgensen, with a note on the nomenclature of the skeleton of the Peridinidae. Archiv für Protistenkunde, 16(1), 25–47. Poulsen, N. E., & Riding, J. B. (2003). The Jurassic dinoflagellate cyst zonation of Subboreal Northwest Europe. Geological Survey of Denmark and Greenland Bulletin, 1, 115–144. Powell, A. J. (1992). Dinoflagellate cysts of the Triassic system. In A. J. Powell (Ed.), A stratigraphic index of

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dinoflagellate cysts (pp. 1–6)., British Micropalaeontological Society Publications Series London: Chapman and Hall. Riding, J. B. (2012). A compilation and review of the literature on Triassic, Jurassic, and earliest Cretaceous dinoflagellate cysts. American Association of Stratigraphic Palynologists, 227pp. (Contributions Series, 46). http://www.palynology.org/aasp-store/4. Riding, J. B., Mantle, D. J., & Backhouse, J. (2010). A review of the chronostratigraphical ages of Middle Triassic to Late Jurassic dinoflagellate cyst biozones of the North West Shelf of Australia. Review of Palaeobotany and Palynology, 162, 543–575. Sarjeant, W. A. S. (1974). Fossil and living dinoflagellates. London: Academic Press. Smayda, T. J. (1997). Harmful algal blooms: their ecophysiology and general relevance to phytoplankton blooms in the sea. Limnology and Oceanography, 42, 1137–1153. Stover, L. E., Brinkhuis, H., Damassa, S. P., De Verteuil, L., Helby, R. J., Monteil, E., et al. (1996). Mesozoic-Tertiary dinoflagellates, acritarchs and prasinophytes. In J. Jansonius & D. C. McGregor (Eds.), Palynology: Principles and applications (pp. 641–750). Dallas, TX: American Association of Stratigraphic Palynologists Foundation. Taylor, F. J. R., Hoppenrath, M., & Saldarriaga, J. F. (2008). Dinoflagellate diversity and distribution. Biodiversity and Conservation, 17, 407–418. Traverse, A. (2007). Paleopalynology (2nd ed.). The Netherlands: Springer.

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Conodonts

1

Introduction

Conodonts (=cone-tooth in Greek) are usually microscopic (0.2–2 mm in length) organisms, although, rare larger specimens up to 25 mm have been recorded (Gabbott et al. 1995; Purnell 1995). Conodonts are elongate, armorless, eel-shaped, and large-eyed marine animals (Briggs et al. 1983; Purnell 1995) (Fig. 1). They are soft-bodied, except for their apparatus of tooth-like phosphatic (bioapatite with a francolite-like structure) elements situated in the mouth and/or the pharynx (Fig. 2(1)). These elements (of the feeding apparatus), after death, are scattered in the sediment on the seafloor and are termed as natural assemblages or bedding plane assemblages, sometimes also composed of fused assemblages (Fig. 2(2)). The conodonts are putative jawless vertebrates (Donoghue et al. 2000) that spanned from the Late Cambrian to the latest Triassic, a duration of *300 Ma (Sweet 1988; Aldridge et al. 1993). Their tooth-like elements (Fig. 2) are the earliest instance of a mineralized skeleton within the vertebrate lineage (Sansom et al. 1992; Donoghue and Sansom 2002; Murdock et al. 2013; Martínez-Pérez et al. 2014a, b). Conodonts are considered as active swimmers of the water column. The conodonts are an important microfossil group for dating Paleozoic shallow-marine carbonates and have been extensively used in paleoecological and biogeographical studies (Sweet and Donoghue 2001) (Tables 1, 2, 3, 4, 5, and 6).

The conodont color alteration index (CAI) (Epstein et al. 1977; Rejebian et al. 1987) has been applied for the interpretation of basinal histories, regional metamorphic studies (Wiederer et al. 2002; Zhang and Barnes 2007; Voldman et al. 2009, 2010) and for hydrocarbon and mineral exploration (Marshall et al. 2001; Trotter et al. 2007), as well as in evaluating Kimberlite (the primary natural source of diamonds) emplacement temperatures (Pell et al. 2015). Additionally, bioapatite (the element that constitutes the animal’s skeleton) archives information on sea water chemistry, hence, their chemical analyzes enables a better insight into ocean geodynamics and past climates (Holmden et al. 1996; Trotter et al. 1999; Wenzel et al. 2000).

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General Morphology

Fossil evidences of soft parts are extremely rare, and wherever they are well-preserved, are suggestive of a chordate affinity for conodonts (Mikulic et al. 1985; Aldridge et al. 1986, 1993; Smith et al. 1987; Sansom et al. 1992; Aldridge and Theron 1993; Gabbott et al. 1995). Complete feeding apparatus with 15 or more elements (Fig. 3) have now been recorded (Briggs et al. 1983). Functional modeling (Aldridge et al. 1987; Purnell 1993; Purnell and Donoghue 1998) and growth studies favor a grasping and processing function for the apparatus (Purnell 1994,

© Springer Nature India Private Limited 2020 S. Jain, Fundamentals of Invertebrate Palaeontology, Springer Geology, https://doi.org/10.1007/978-81-322-3962-8_5

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Fig. 1 Line drawing of the Early Carboniferous (Dinantian, Mississippian) Clydagnathus cf. cavusiformis Rhodes et al. (1969) from the Granton Shrimp Bed (Edinburgh, Scotland). Modified from Briggs et al. (1983)

1995); the elements being the components of the oropharyngeal feeding apparatus (Aldridge et al. 2013) (Fig. 2).

2.1 Elements Most preCarboniferous conodonts elements are constructed of two parts, the crown (readily preserved and the more abundant component)

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and the variable basal body (Fig. 4(1)). The basal body occupies an opening, the basal cavity (Fig. 4(2–5)), within the crown that comprises of hyaline lamella tissue with growth lines (Fig. 4 (1)) and an internal opaque tissue, called the white matter (Fig. 4(5)). The latter is so called, as, in translucent fossils, it appears white under reflected light. However, in transmitted light, it appears dark. The basal cavity (Fig. 4(2–5)) is an excavation that increases in size with specimen growth. Hence, its size is dependent on the size of the specimen. Another taxonomically important structure is the pit (Fig. 4(7)) which is formed when growth proceeds laterally from or above the initial point of secretion. Its size does not increase with ontogenetic growth but ceases after a few growth lamellae have been formed (Fig. 4(7)). Hence, large specimens may have small pits. The germ denticles (Fig. 4(5)) are structures that have been suppressed during ontogeny due to overgrowth by adjacent structures; these are best noted in translucent fossils in transmitted light. It must be mentioned that the electron microscopy has revealed that the lamellar crown tissue (Fig. 4(1)) is possibly homologous to the enamel and the white matter may be a form of the enamel, quite unique to conodonts. In general, the conodonts grew by polycyclic, appositional addition of layers of the crown enamel, so that the inner lamellae are the oldest (Fig. 4(1)). The lamellae, within the crown, based on their incremental patterns, are termed as minor and major (Armstrong and Smith 2001). In Protopanderodus varicostatus, the minor increments have a minimum thickness of *1 lm (likely deposited in a day), although, some minor increments have been noted to be as thick as 7 lm and most likely represent growth episodes, lasting up to a week.

Fig. 2 The conodont animal. 1: Line drawing of the conodont animal showing its major morphological features. 2: A natural assemblage of conodont elements of Scottognathus typicus (Rhodes) from Pennsylvanian rocks in Illinois (Scottognathus is a junior synonym of Idiognathodus) (after Sweet and Donoghue 2001). 3: The postero-ventral view of the head of the conodont animal showing the position of elements (apparatus) of the Lochkovian (earliest Devonian) Pandorinellina rernscheidensis (Ziegler) (modified after Dzik 1991). 4: Illustration of conodont’s M, S and P elements in relationship to one another within the animal’s exposed oral cavity. 5: Enlarged view of the two sets of P elements (P1 and P2) (modified from Purnell and Jones 2012)c

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General Morphology

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Table 1 Stratigraphic occurrences of important marker taxa (203–175 Ma)

2.2 Composite Elements The conodont elements are varied in shape and are of taxonomic relevance (see Sweet 1988 for details). Two major categories are noted: compound or composite and simple or single teeth. The composite elements are differentiated into four main groups (Fig. 4(5–10)). These are:

2.2.1 Blade-Type Conodonts These are elongate, laterally compressed forms with a row of denticles that are fused, except at

their tips (Fig. 4(5)). They functioned as cutting teeth (Purnell and von Bitter 1992). These are index fossils from Silurian to Triassic.

2.2.2 Bar-Type Conodonts These are commonly branched, and with thin bars (Fig. 4(6)). They are the most conspicuous and commonly occurring element within many associations. They are evolutionarily conservative and long ranging with stable morphologies, thus, biostratigraphically not important.

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Table 2 Stratigraphic occurrences of important marker taxa (173–164 Ma)

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98 Table 3 Stratigraphic occurrences of important marker taxa (163–146 Ma)

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General Morphology

Table 4 Stratigraphic occurrences of important marker taxa (145–127 Ma)

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Table 5 Stratigraphic occurrences of important marker taxa (126–101 Ma)

2.2.3 Platform-Type Conodonts These highly differentiated forms (Fig. 4(7–10)), through the development of broad flanges into plates, probably evolved from blade- and bartype conodonts (Fig. 4(5 and 6)). Many of these platform-type conodonts are excellent index fossils for the Ordovician–Triassic duration. Morphologically, a blade is the edge-like free portion at the anterior end, and in many cases, it integrates into a carina on the upper side of the platform (Fig. 4(8)). The protrusions on one or both sides

of the platform are called Lobes (Fig. 4(8)). On the lower side of the platform (as in Polygnathus; Fig. 4(7 and 8)), the main elements are: (a) the pit around the growth center, (b) the attachment area, where the edges of growth lamellae are visible, (c) the crimp, or the portion outside the basal organ that does not expose the edges of growth lamellae, and (d) the keel in the center, which corresponds to the carina at the upper surface. The lower side of some platforms (as in Gnathodus; Fig. 4(9 and 10)) is entirely excavated and

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General Morphology

Table 6 Stratigraphic occurrences of important marker taxa (100–67 Ma)

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Fig. 3 Apparatus architecture comparisons. 1: Six-element apparatus of Archeognathus primus; 2: Fifteen-element apparatus of Iowagnathus grandis (modified after Liu et al. 2017); 3: Fifteen-element apparatus of the ozarkodinid type (modified after Aldridge et al. 2013); 4: Ninteen-element apparatus of Promissum pulchrum. Modified after Donoghue et al. 2008)

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Fig. 4 Morphological terminology of conodonts. 1: Cross section of the Late Devonian Palmatolepis showing the platform with anisometric growth. The lamellae are more widely spaced in one direction (modified after Müller and Nogami, 1971). 2–4: Basal cavity. 3: Spathognathodus (Ordovician–Permian): Internal structure of conodonts lamellar structure barely masked by white matter; 4: Ozarkodina (Silurian–Devonian): Lamellar structure completely filled with white matter; 5: Blade type. 6: Bar type; 7–10: Platform type; 7 and 8: Polygnathus; 9 and 10: Gnathodus

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Fig. 5 Crown terminology

display the edges of growth lamellae on the entire surface, termed as cup (Fig. 4(10)). In the center, a furrow (Fig. 4(9)), homologous to the keel, is developed.

angulate, segminate, and carminate (Fig. 6(8– 12)). Element details are illustrated in Fig. 6 and are briefly enumerated below.

2.3.1 Ramiform Elements

2.3 Simple Elements The simple coniform elements have two parts, a broad base that encloses the basal cavity and a solid and tapering unit (apex) called the cusp; cusp can be straight or curved (Fig. 5). While interpreting conodont taxonomy, the tip (apex) is always placed up with the base, horizontal (Fig. 5). Based on curvature, the coniform elements are divided into two, geniculate and non-geniculate (Fig. 5; see also Fig. 6, inbox). Based on the number of processes and their relationship to cusp, the ramiform elements are divided into seven types, alate, digyrate (extensiform and breviform), quadriramate, dolabrate, bipennate, tertiopedate, and multiramate (Fig. 6 (1–7)). Based on the number and arrangement of primary processes, the pectinform elements are divided into five types—stellate, pastinate,

Alate These elements are bilaterally symmetrical and have a caudal and two lateral processes (Fig. 6(1)). Digyrate These elements are broadly similar in shape to alate elements, but they are asymmetrical; the caudal process is only rarely developed, and the lateral processes are usually unequally developed and variably twisted in opposite directions (Fig. 6(2 and 3)). Quadriramate These elements have rostral, caudal, and two lateral processes (Fig. 6(4)). Dolabrate These elements only have a caudal process and are commonly pick-shaped (Fig. 6(5)).

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General Morphology

Fig. 6 Element terminology

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Fig. 7 Topological scheme of notations. 1: Comparative schemes put forward by Purnell et al. (2000) and Sweet (1988). 2: Nicoraella apparatus architecture (after Huang et al. 2018)

Bipennate These elements have a caudal and rostral process; the rostral is usually shorter and commonly curves or is deflected inwards (Fig. 6(6)).

2.3.2 Pectinform Elements Elements with a dorsal process are again divided into categories based on the number of primary processes (Fig. 6(8–12)).

Tertiopedate These elements have a caudal process and lateral processes that are asymmetrically disposed about the cusp (Fig. 6(7)).

Stellate These elements have four primary processes that may bifurcate to form secondary processes (Fig. 6(8)).

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General Morphology

Pastinate These elements have three primary processes, dorsal, ventral, and a rostral or caudal process. The processes may be adenticulate represented only by a conspicuous flange (Fig. 6(9)). Carminate and Angulate These elements have dorsal and ventral processes. In a carminate element, the aboral margin is straight, whereas in angulate ones, this is arched (Fig. 6(10 and 12)). Segminate These elements possess a dorsal process that can bear one or more rows of nodes or ridges (Fig. 6 (11)).

2.4 Element Notation and Apparatus The elements form a bilaterally symmetrical apparatus (Fig. 7) located in the head region of the conodont animal. Each conodont species is reconstructed as having a certain number of elements with various shapes, including the anteriorly positioned M and S (Sa, Sb, Sc, and Sd), and the posteriorly-positioned P (Pa and Pb) elements (see Sweet 1988; Purnell et al. 2000) (Fig. 7(1)). Broadly, the elements fall into two distinct domains: a rostral domain of paired S elements (Sb, Sc, and Sd; plus a single Sa element on the midline), associated with a pair of dorsolateral M elements, and a caudal domain comprising up to four pairs of P elements (the Pa, Pb, Pc, and Pd elements) (Fig. 7; see Sweet 1988). Later, Purnell et al. (2000) introduced new terms where element locations are defined according to the relationships between elements

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with reference to the principal axes of the body, confirmed in bedding plane assemblages (Fig. 7). In the standard ozarkodinid apparatus, it takes the form of letters with numeric subscripts (such as P1, P2, S0–S4, M; the S locations are numbered outwards from the central S0 (Fig. 7). The three-dimensional architecture of relatively few conodont apparatuses are known (Aldridge et al. 1987; Purnell and Donoghue 1998) wherein, the apparatus of the ozarkodinids is considered as the stereotypical apparatus for all non-coniform species (Fig. 3). However, in recent years, based on the find of discrete elements, fused clusters, bedding plane assemblages, and articulated assemblages associated with the soft-tissue, several apparatus models have been used to reconstruct the conodont animal (Purnell and Donoghue 1997, 1998; Orchard 2005; Goudemand et al. 2011, 2012; Agematsu et al. 2017; Zhang et al. 2017). But, owning to the animal’s disintegrated nature (after death), large discrepancies remain among these models. Additionally, even in well-preserved natural assemblages (bedding plane assemblages and fused clusters), the component elements are masked due to one or a combination of the following factors. They are obscured (see Fig. 1 (2)): (1) by one another, (2) by the surrounding matrix, and/or (3) by diagenetic mineral crusts. For cases like these, recently, a non-destructive tomographic technique, the synchrotron radiation X-ray tomographic microscopy (SRXTM) has been used successfully employed to better understand (and document) the architecture of the conodont apparatus (Fig. 8) (see also Jones et al. 2012a, b; Murdock et al. 2013, 2014; Martínez-Pérez et al. 2014, 2016; Suttner et al. 2017; Huang et al. 2018).

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Fig. 8 Surface models of Middle Triassic 15-element Nicoraella showing apparatus architecture as revealed by synchrotron X-ray microtomography (SRXTM) from the Luoping Biota (Yunnan Province, Southwest China). Illustration shows “a single alate element located in the S0 position, flanked successively abaxially by pairs of breviform digyrate S1 and S2 elements, bipennate S3 and S4 elements, and a pair of inwardly curved breviform digyrate M elements. Carminate elements occupy the P1 and P2 positions” (after Huang et al. 2018)

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General Morphology

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5 Conodonts

b Fig. 9 Conodont classification (after Sweet 1988). 1–7: Order Proconodontida: “uni-membrate skeletal apparatus

composed of relatively large, deeply excavated, smooth-surfaced, hyaline coniform elements that are subsymmetrically oval transverse sections and keels on the anterior and/or posterior margins” (Sweet 1988); 1: Proconodontus (Late Cambrian), the oldest known conodont; 2: Eoconodontus (latest Cambrian–Early Ordovician); 3: Corydylodus (Late Cambrian–Early Ordovician); 4: Fryxellodontus; (Late Cambrian–Early Ordovician); 5: Ansella (Middle Ordovician); 6: Belodella (Silurian–Devonian); and 7: Corydylodus 8–22: Order Prioniodontida: “conodonts in which one or both of the P positions in the apparatus are occupied by pastinate coniform or pectiniform elements or their platformed equivalents” (Sweet 1988); both the Early Ordovician Rossodus (8) and Tripodus (9) have the oldest prioniodontide skeleton (some authors have assigned Tripodus to Acodus or Diaphorodus; 10: Pygodus (Ordovician); 11: Icriodella (Early Silurian); 12: Pedavis (Early Middle Devonian); 13: Distomodus (Silurian; morphologically Distomodus is very close to Pedavis; Sweet 1988); 14: Multiostodus (Ordovician); 15: Prioniodus (Early Middle Ordovician; Whiterockian); 16 and 17: Oistodus (Ordovician); 18: Phragmodus (Ordovician); 19: Plectodina (Late Ordovician); 20: Pterospathodus (Early Silurian); 21: Polyplacognathus (Ordovician); 22: Rhipidognathus (Late Ordovician); 23–34: Protopanderodontida (Ordovician): this includes “uni- to multi-membrate skeletal apparatuses composed of longitudinally striated, laterally unfurrowed coniform elements” (Sweet 1988); 23–26: Apparatus of Protopanderotus (Ordovician); 27: Belodina (Early Middle Ordovician); 28: Clavohamulus (Early Ordovician); 29: Cornuodus (Ordovician); 30: Dapsilodus (Ordovician–Silurian); 31: Parapanderodus (Early Ordovician); 32: Strachanognathus (Late Ordovician); 33: Drepanoistodus (Ordovician); 34: Oneotodus (Ordovician); 35–45: Prioniodinida: “highly distinctive extensiform digyrate elements in the two P positions. Dentiles are characterically discreet and peg-like; white matter is commonly of minor amount” (Sweet 1988); 35–41: Apparatus plan of Periodon (Early Ordovician); 42: Erraticodon (Ordovician) is the oldest Prioniodinida member and appeared the late Early Ordovician and became cosmopolitan; 43: Ellisonia (Atokan; Pennsylvanian, Late Carboniferous); 44: Oulodus (Late Ordovician); 45: Bactrognathus (Mississippian, Early Carboniferous); 46: Merrillina (Permian); 47–56: Ozarkodinida (Late Middle Ordovician–Earliest Triassic) “P positions occupied by carminate and angulate pectiniform elements or their platformed analogues” (Sweet 1988); 47: Hindeodus (Early Mississippian; Kinderhookian); 48: Cavusgnathus (Early Mississippian, Carboniferous); 49: Siphonodella (Late Devonian–Mississippian, Early Carboniferous); 50: Gnathodus (Mississippian, Early Carboniferous); 51: Indiognathodus (Late Pennsylvanian, Carboniferous); 52: Kockelella (Early Silurian); 53: Mestognathus (Mississippian, Early Carboniferous); 54: Palmatolepis (Late Devonian); Polygnathus (Early Devonian to Early Carboniferous); 56: Sweetgnathus (Carboniferous–Permian)

3

Classification

The classification followed here is after Sweet (1988) who recognized the following orders: Proconodontida, Prioniodontida, Protopanderodontida, Prioniodinida, Panderodontida, and Ozarkodinida (Fig. 9). Order Proconodontida is best represented by the Late Cambrian Proconodontus (Fig. 9(1)). The skeletal apparatus is composed of large, deeply excavated, smooth, non-geniculate coniform elements (Fig. 9(1–7)). Order Prioniodontida (Fig. 9(8–22)) possess

pastinate coniform or pectiniform elements or their platformed equivalents (Sweet 1988). Order Protopanderodontida (Fig. 9(23–34)) is best exemplified by Protopanderodus (Fig. 9(23–26)) that lack white matter (i.e. hyaline) and have non-geniculate coniform elements with longitudinal striations. Order Prioniodinida (Fig. 9(35– 46)) is best represented by Periodon (Fig. 9(35– 41)). Order Panderodontida is similar to Protopanderodontida but contains laterally furrowed

3

Classification

Fig. 10 Panderodus gracilis (Branson and Mehl) (modified from Sweet 1988)

111

112

Fig. 11 Representative conodont species (see also Fig. 9)

5 Conodonts

3

Classification

elements and is represented by Panderodus (Fig. 10). Order Ozarkodinida (Fig. 9(47–56)) is best known by genus Ozarkodina.

4

Geological History

The most primitive conodonts are single cones that dominated during the Early Ordovician with a peak in the Arenigian (late Early Ordovician); the first platform-type conodonts occurred around this time, as well. The earliest conodonts are known from the Precambrian, but more commonly in the Late Cambrian, with increased diversity in the Ordovician and Devonian. Conodont diversity and abundance declined in the Silurian. During the Early and Mid-Devonian diversity gradually increased, reaching an acme in the late Devonian. In the Early Carboniferous conodonts remained abundant and widespread but diversity decreased during the late Carboniferous. The conodonts survived the Permo-Triassic boundary extinctions but became extinct by late Triassic, coinciding with the diversification of dinoflagellates and the first appearance of calcareous nannofossils. Representative conodont species, through time, are illustrated in Fig. 11.

References Agematsu, S., Uesugi, K., Sano, H., & Sashida, K. (2017). Reconstruction of the multielement apparatus of the earliest Triassic conodont, Hindeodus parvus, using synchrotron radiation X-ray micro-tomography. Journal of Paleontology, 91, 1220–1227. Aldridge, R. J., Briggs, D. E. G., Clarkson, E. N. K., & Smith, M. P. (1986). The affinities of conodonts— New evidence from the Carboniferous of Edinburgh, Scotland. Lethaia, 19, 279–291. Aldridge, R. J., Briggs, D. E. G., Smith, M. P., Clarkson, E. N. K., & Clark, N. D. L. (1993). The anatomy of conodonts. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 340, 405–421. Aldridge, R. J., Murdock, J. E., Gabbott, S. E., & Theron, J. N. (2013). A 17-element conodont apparatus from the Soom Shale Lagerstätte (Upper Ordovician). South Africa: Palaeontology, 56, 261–276.

113 Aldridge, R. J., Smith, M. P., Norby, R. D., & Briggs, D. E. G. (1987). The architecture and function of Carboniferous polygnathacean conodont apparatuses. In R. J. Aldridge (Ed.), Palaeobiology of conodonts (pp. 63–76). Chichester: Ellis Horwood. Aldridge, R. J., & Theron, J. N. (1993). Conodonts with preserved soft tissue from a new Upper Ordovician Konservat-Lagetstätte. Journal of Micropalaeontology, 12, 113–117. Armstrong, H. A., & Smith, C. J. (2001). Growth patterns in euconodont crown enamel: Implications for life history and mode of life reconstruction in the earliest vertebrates. Proceedings of the Royal Society, Series B, 268, 815–820. Briggs, D. E. G., Clarkson, E. N. K., & Aldridge, R. J. (1983). The conodont animal. Lethaia, 16, 1–14. Donoghue, P. C. J., Forey, P. L., & Aldridge, R. J. (2000). Conodont affinity and chordate phylogeny. Biological Reviews, 75, 191–251. Donoghue, P. C. J., Purnell, M. A., Aldridge, R. J., & Zhang, S. (2008). The interrelationships of ‘complex’ conodonts (vertebrata). Journal of Systematic Palaeontology, 6(2), 119–153. Donoghue, P. C. J., & Sansom, I. J. (2002). Origin and early evolution of vertebrate skeletonization. Microscopy Research and Technique, 59, 352–372. Dzik, J. (1991). Evolution of oral apparatuses in the conodont chordates. Acta Palaeontologica Polonica, 36(3), 265–323. Epstein, A. G., Epstein, J. B., & Harris, L. D. (1977). Conodont color alteration-an index to organic metamorphism. Geological survey professional paper 995, 1–27. Gabbott, S. E., Aldridge, R. J., & Theron, J. N. (1995). A giant conodont with preserved muscle tissue from the Upper Ordovician of South Africa. Nature, 374, 800– 803. Goudemand, N., Orchard, M. J., Tafforeau, P., Urdy, S., Brühwiler, T., Brayard, A., et al. (2012). Early Triassic conodont clusters from South China: Revision of the architecture of the 15 element apparatuses of the superfamily Gondolelloidea. Palaeontology, 55, 1021–1034. Goudemand, N., Orchard, M. J., Urdy, S., Bucher, H., & Tafforeau, P. (2011). Synchrotron-aided reconstruction of the conodont feeding apparatus and implications for the mouth of the first vertebrates. Proceedings of the National Academy of Sciences, USA, 108, 8720–8724. Holmden, C., Creaser, R. A., Muehlenbachs, K., Bergström, S. M., & Leslie, S. A. (1996). Isotopic and elemental systematics of Sr and Nd in 454 Ma biogenic apatites: Implications for paleoseawater studies. Earth and Planetary Science Letters, 142, 425–437. Huang, J.-Y., Martínez-Pérez, C., Hu, S.-X., Donoghue, P. C.J., Zhang, Q.-Y., Zhou, C.-Y., Wen, W., Benton, M. J., Luo, M., Yao, H.-Z., & Zhang, K.-X. (2018). Middle Triassic conodont apparatus architecture revealed by synchrotron X-ray microtomography.

114 Palaeoworld. https://doi.org/10.1016/j.palwor.2018. 08.003. Jones, D. O., Evans, A. R., Rayfield, E. J., Siu, K. K., & Donoghue, P. C. J. (2012a). Testing micro structural adaptation in the earliest dental tools. Biology Letters, 8, 952–955. Jones, D. O., Evans, A. R., Rayfield, E. J., Siu, K. K., & Donoghue, P. C. J. (2012b). The sharpest tools in the box? Quantitative analysis of conodont element functional morphology. Proceedings of the Royal Society B: Biological Sciences, 279, 2849–2854. Liu, H. P., Bergström, S. M., Witzke, B. J., Briggs, D. E. G., McKay, R. M., & Ferretti, A. (2017). Exceptionally preserved conodont apparatuses with giant elements from the Middle Ordovician Winneshiek Konservat-Lagerstätte, Iowa, USA. Journal of Paleontology, 91(3), 493–511. Marshall, C. P., Mar, G. L., Nicoll, R. S., & Wilson, M. A. (2001). Organic geochemistry of artificially matured conodonts. Organic Geochemistry, 32, 1055–1071. Martínez-Pérez, C., Plasencia, P., Jones, D., KolarJurkovšek, T., Sha, J., Botella, H., et al. (2014). There is no general model for occlusal kinematics in conodonts. Lethaia, 47, 547–555. Martínez-Pérez, C., Rayfield, E. J., Botella, H., & Donoghue, P. C. J. (2016). Translating taxonomy into the evolution of conodont feeding ecology. Geology, 44, 247–250. Martínez-Pérez, C., Rayfield, E. J., Purnell, M. A., & Donoghue, P. C. J. (2014). Finite element, occlusal, microwear and microstructural analyses indicate that conodont microstructure is adapted to dental function. Palaeontology, 57(5), 1059–1066. Müller, K. J., & Nogami, Y. (1971). Über den Feinbau der Conodonten. Memoirs of the Faculty of Sciences of the Kyoto University, Series of Geology and Mineralogy, 38, 1–88. Mikulic, D. G., Briggs, D. E. G., & Kluessendorf, J. (1985). A Silurian soft-bodied biota. Science, 228, 715–717. Murdock, D. J. E., Rayfield, E. J., & Donoghue, P. C. J. (2014). Functional adaptation underpinned the evolutionary assembly of the earliest vertebrate skeleton. Evolution and Development, 16, 354–361. Murdock, D. J. E., Sansom, I. J., & Donoghue, P. C. J. (2013). Cutting the first ‘teeth’—A new approach to functional analysis of conodont elements. Proceedings of the Royal Society B: Biological Sciences, 280, 20131524. Orchard, M. J. (2005). Multielement conodont apparatuses of Triassic Gondolelloidea. Special Papers in Palaeontology Series, 73, 73–101. Pell, J., Russell, J. K., & Zhang, S. (2015). Kimberlite emplacement temperatures from conodont geothermometry. Earth and Planetary Science Letters, 411, 131–141. Purnell, M. A. (1993). The Kladognathus apparatus (Conodonta, Carboniferous): Homologies with ozarkodinids and the prioniodinid Bauplan. Journal of Paleontology, 67, 875–882.

5 Conodonts Purnell, M. A. (1994). Skeletal ontogeny and feeding mechanisms in conodonts. Lethaia, 27, 129–138. Purnell, M. A. (1995). Large eyes and vision in conodonts. Lethaia, 28, 187–188. Purnell, M. A., & Donoghue, P. C. J. (1997). Architecture and functional morphology of the skeletal apparatus of ozarkodinid conodonts. Philosophical Transactions of the Royal Society of London. Series B, 352, 1545– 1564. Purnell, M. A., & Donoghue, P. C. J. (1998). Skeletal architecture, homologies and taphonomy of ozarkodinid conodonts. Palaeontology, 41, 57–102. Purnell, M. A., Donoghue, P. C. J., & Aldridge, R. J. (2000). Orientation and anatomical notation in conodonts. Journal of Paleontology, 74, 113–122. Purnell, M. A., & Jones, D. (2012). Quantitative analysis of conodont tooth wear and damage as a test of ecological and functional hypotheses. Paleobiology, 38(4), 605–626. Purnell, M. A., & von Bitter, P. H. (1992). Blade-shaped conodont elements functioned as cutting teeth. Nature, 359, 629–631. Rejebian, V. A., Harris, A. G., & Huebner, J. S. (1987). Conodont color and textural alteration: An index to regional metamorphism, contact metamorphism, and hydrothermal alteration. Geological Society of America Bulletin, 99, 471–479. Rhodes, F. H. T., Austin, R. L., & Druce, E. C. (1969). British Avonian Carboniferous conodont faunas, and their value in local and intercontinental correlation. Bulletin of the British Museum (Natural History) Geology, (Suppl, 5), 1–313. Sansom, I. J., Smith, M. P., Armstrong, H. A., & Smith, M. M. (1992). Presence of the earliest vertebrate hard tissues in conodonts. Science, 256, 1308–1311. Smith, M. P., Briggs, D. E. G., & Aldridge, R. J. (1987). A conodont animal from the lower Silurian of Wisconsin, U.S.A., and the apparatus architecture of panderodontid conodonts. In R. J. Aldridge (Ed.), Palaeobiology of conodonts (pp. 91–104). Chichester: Ellis Horwood. Suttner, T. J., Kido, E., & Briguglio, A. (2017). A new icriodontid conodont cluster with specific mesowear supports an alternative apparatus motion model for Icriodontidae. Journal of Systematic Palaeontology, 16, 909–926. Sweet, W. C. (1988). The conodonta: Morphology, taxonomy, paleoecology, and evolutionary history of a long-extinct animal phylum. Oxford: Clarendon Press. Sweet, W. C., & Donoghue, P. C. J. (2001). Conodonts: Past, present, future. Journal of Paleontology, 75(6), 1174–1184. Trotter, J. A., Fitz, J. D., Kokkonen, G. H., & Barnes, C. R. (2007). New insights into the ultrastructure, permeability, and integrity of conodont apatite determined by transmission electron microscopy. Lethaia, 40, 97–110. Trotter, J. A., Korsch, M. J., Nicoll, R. S., & Whitford, D. J. (1999). Sr isotopic variation in single conodont

References elements: Implications for defining the Sr seawater curve. Bollettino della Societa Paleontologica Italiana, 37(2–3), 507–514. Voldman, G. G., Albanesi, G. L., & Ramos, V. A. (2009). Ordovician metamorphic event in the carbonate platform of the Argentine Precordillera: Implications for the geotectonic evolution of the proto-Andean margin of Gondwana. Geology, 37, 311–314. Voldman, G. G., Bustos-Marún, R. A., & Albanesi, G. L. (2010). Calculation of the conodont Color Alteration Index (CAI) for complex thermal histories. International Journal of Coal Geology, 82(1–2), 45–50. Wenzel, B., Lécuyer, C., & Joachimski, M. M. (2000). Comparing oxygen isotope records of Silurian calcite and phosphate–δ18O compositions of brachiopods and conodonts. Geochimica et Cosmochimica Acta, 64 (11), 1859–1872.

115 Wiederer, U., Königschof, P., Feist, R., Franke, W., & Doublier, M. P. (2002). Low grade metamorphism in the Montagne Noire (S–France): Conodont Alteration Index (CAI) in Paleozoic carbonates and implications for the exhumation of hot metamorphic core complex. Schweizerische Mineralogische und Petrographische Mitteilungen, 82, 393–407. Zhang, S., & Barnes, C. R. (2007). Late Ordovician-early Silurian conodont biostratigraphy and thermal maturity, Hudson Bay Basin. Bulletin of Canadian Petroleum Geology, 55, 179–216. Zhang, M., Jiang, H., Purnell, M. A., & Lai, X. (2017). Testing hypotheses of element loss and instability in the apparatus composition of complex conodonts: Articulated skeletons of Hindeodus. Palaeontology, 60, 595–608.

6

Radiolarians

1

Introduction

Radiolarians are microscopic (20–300 µm) marine organisms with an exclusive planktonic mode of life. They are also the most abundant microzoolankton within the marine realm with a very wide distribution extending from pole to equator and from shallow to abyssal depths (Anderson 1983; Afanasieva et al. 2005; Boltovskoy et al. 2010). Radiolarians have a continuous fossil record since the earliest Cambrian (Fig. 1) and are also one of the earliest groups of microorganisms capable of inhabiting various regions of the ocean (the ecological plasticity of Afanasieva et al. 2005). The early forms had a spherical skeleton with a radial symmetry (Braun et al. 2007; Maletz 2011) (Fig. 1). But it must be kept in mind that the Early Cambrian material is poorly preserved and at times fragmentary to merit positive identifications, thus, leaving the question of the earliest radiolarian record, still open (see Maletz 2011 but also see Cao et al. 2014; Chang et al. 2018).

2

Morphology

The cell cytoplasm is divided into an outer ectoplasm and an inner endoplasm, separated by a perforate organic membrane called the central capsule (Fig. 2(1)). The ectoplasm secretes the skeleton/test and bulk of it lies within it only. The nucleus is within the endoplasm (Fig. 2). From the central capsule, pseudopodia radiate outwards as central rods of fibers called axopodia; if they are thread-like, they are called filipodia. Calymma, a zone of frothy, gelatinous bubbles occurs within ectoplasm (Fig. 2(1)). The mineral skeleton lies inside the cytoplasm and is composed of opal (98% amorphous SiO2
nH2O; Hurd and Takahashi 1981; Petrushevskaya 1981; Takahashi and Honjo 1981) with small amounts (1–4%) of Mg, Ca, Al, and Na (Anderson 1983). The mineralized skeleton consists of either radial or tangential elements, or both. The radial elements include loose spicules, external spines or internal bars, whereas the tangential elements consist of a porous lattice shell of variable

© Springer Nature India Private Limited 2020 S. Jain, Fundamentals of Invertebrate Palaeontology, Springer Geology, https://doi.org/10.1007/978-81-322-3962-8_6

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Fig. 1 Early Cambrian radiolarian records (chronostratigraphy based on Peng 2003; Geyer and Landing 2004; Babcock and Peng 2007). 1: Braun et al. (2007), Ningqiang, Shaanxi (uppermost Precambrian or basal Cambrian); 2: Danelian and Bengtson (2009), Australia (Nemakit/Daldynian); 3: Braun et al. (2007), Xintangwu, Zhejiang (Meishucunian); 4: Hao and Shu (1987), Zhenba, Shaanxi (Eoredlichia Zone); 5: Obut and Iwata (2000), Gorny Altai (Botomian); 6: Won and Below (1999), Georgina Basin, Queensland, Australia (Templetonian, Floran, Undillian); 7: White (1986), Utah (Middle Cambrian, Ptychagnostus atavus Zone); 8: Dong et al. (1997), Paibi, Hunan Province, China (basal Hunanian); 9: Won and Iams (2002), western Newfoundland (Franconian, Trempealeauan). Arrows marks exact ages. Gray arrows indicate material not considered to be radiolarians. For more details see Maletz (2011), image curtsey Jörg Maletz and with permission from Elsevier (Paleoworld)

morphology, such as spheres, spindles, and cones (Fig. 2(2)). Geologists are concerned with only one radiolarians group, the polycystines (Class Polycystinea) that includes the radially symmetrical spumellarians (Order Spumellaria Ehrenberg) (Fig. 3) and the helmet-shaped nassellarians (Nassellaria Ehrenberg) (Fig. 4). Both are important because of their solid opaline skeleton which is more resistant than those of silicoflagellates and diatoms but somewhat susceptible to dissolution as seawater is undersaturated relative to silica. The spumellarians possess a radial symmetry along a central point (spherical symmetry) (Fig. 3(2)), whereas the nassellarians has a radial symmetry along the long axis (non-spherical, usually bilateral symmetry) (Fig. 4(3)). Both have a solid skeleton made of amorphous opaline silica (SiO2
nH2O). One other minor order

(Order Phaeodarea) that has no fossil record has a skeleton made by the admixture of organic matter (dominant constituent) and 20% opaline silica. Although the radiolarians occur as a simple cell but some spumellarians occur as colonies of numerous individuals each bearing its own skeleton. These colonies are as large as 250 mm. The radiolarian skeleton is composed of a network of two types of elements, the elongate elements attached at one end only called spines or connected at both ends called bars (Fig. 3(2)). In some polycystines, the entire skeleton is made up of an association of simple spines called spicules (Fig. 3(1)); the simplest skeleton of both spumellarians and nassellarians is the spicule. The spicules range in size from 100 to 400 lm and in some rare cases, up to 2 mm. The skeletal geometry and perforations on the capsular membrane distinguish these two groups— spumellarians and nassellarians.

2

Morphology

119

Fig. 2 A typical radiolarian cell (Thalassicola). Cross section of a spumellarian displaying Nucleus, Endoplasm and Ectoplasm (1) with respect to the concentric lattice shells and radial spines (2) (modified after Westphal 1976). See text for explanation

The Spumellaria are characterized by spherical skeletal shapes (Spheres), where the radial spines (=Main spine) extends from the surface of the sphere (Fig. 3(2)). The skeleton generally consists of two or more nested spheres that are concentric and connected by radial bars (Fig. 3 (2)). The main outer shell is called the cortical

shell and the inner one is the medullary shell (Fig. 3(2)). The innermost spherical shell is generally very small but is characteristic of radiolarians. The latticed shell wall is a meshwork of bars that forms closely spaced pores; they are mostly hexagonal in shape (Fig. 3(3–7)). The shape and the distribution of pores are

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Fig. 3 Spumellarian skeletal morphology (modified from Haq and Boersma 1998)

consistently same in a species, hence, both characters are of taxonomic importance. The latticed skeleton is equally varied in shape (Fig. 3(8–13)). The nassellarian spicule is usually facetted and has a distinct organization of spines (Fig. 4 (1–4); the various types of spine include A: Apical spine; D: Dorsal spine; PL: Primary lateral spine; V: Vertical spine; SL: Secondary lateral spine). Although the spicules are similar to those of the co-occurring sponges but the

former is solid and does not possess a central space. In nassellarians, the Median bar is of taxonomic importance due to its distinctive structure enabling categorization into various groups (Fig. 4(1)). The arrangement of the median bar and spines is collectively called the collar structure that rests between the head (cephalus) and the body (thorax) (Fig. 4(3)). The spines divide the cephalus into two parts, the larger eucephalic lobe (EUC) with the median bar at its base and the smaller anicephalic lobe

2

Morphology

121

Fig. 4 Nassellarian skeletal morphology (modified from Haq and Boersma 1998)

(Fig. 4(3)). The spines may also be associated with the Tube (Fig. 4(4)). The median bar has axostyle supports which are downward projections (see (Fig. 4(4)). A lumber structure (Fig. 4 (3)) separates the thorax with the abdomen

(Fig. 4(3)); those lying below the abdomen are called postabdominal segments that has an open or a constricted aperture (Fig. 4(3)) or a peristome (a basal ring; Fig. 4(6)). The peristome may be without pores (unpored; Fig. 4(6)) or ragged

122

(Fig. 4(7)). That on which a terminal segment rests is called feet (singular = foot) (Fig. 4(5–8)); the subterminal appendages are called wings or shoulders (Fig. 4(8)). The cephalus (Fig. 4(3)) has varied morphological shapes, from spherical to elongate to subcylindrical and contains processes such as horns or spines (Fig. 4(9–11)). The shape of shell segments (Fig. 4.3) is of taxonomic value and occur in different shapes (Fig. 4(12–19)). Even the pores (Fig. 4(21 and 22)) within the segment are arranged differently and therefore are of taxonomic value, as well; the pores also occur in different shapes (Fig. 4 (22–25)).

6 Radiolarians

3

Geological History

The Permian/Triassic crisis was a period of marked radiolarian extinctions (of orders Albaillellaria and Latentifistularia), followed by the spectacular diversification of Spumellaria and Nassellaria in Early-Mid Triassic (Fig. 5). Broadly, the radiolarian diversity gradually increased from Cambrian to Jurassic, remained stable until the Cretaceous, and thereafter, decreased slightly (see De Wever et al. 2001, 2003) (Fig. 5). The Phanerozoic records three major mass extinction events—at the Permian/Triassic boundary, at the Triassic/

Fig. 5 Radiolarian diversity (Family), extinctions (Species and Genera), and polycystine diversity of radially symmetrical spumellarians (Order Spumellaria Ehrenberg) and helmet-shaped nassellarians (Nassellaria Ehrenberg), along with Order Albaillellaria. Modified after Anderson (1983), De Wever et al. (2001) and Afanasieva et al. (2005)

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Geological History

123

Fig. 6 Ordovician radiolarian biostratigraphy (after Maletz 2011). 1: Basal Tremadocian, western Newfoundland, except Archeoentactinia reedae from Won et al. (2002); 2: Protoproventocitum sp. (Won et al. 2007); 3: Maletz and Bruton (2007); 4: Cow Head Group, St. Paul’s Inlet, western Newfoundland (Won and Iams 2002); 5: Maletz and Bruton (2008); 6: Viola Limestone, Katian, Alabama, except Protoceratoikiscum (Noble and Webby 2009); 7: After Noble and Webby (2009); Graptolite biostratigraphy based on Maletz (2007). Dapin. = Dapingian; Hir. = Hirnantian. (after Maletz 2011; curtsey Jörg Maletz and with permission from Elsevier (Paleoworld)

Jurassic boundary, and at the Cretaceous/Tertiary (K/T) boundary (Lethiers 1998; De Wever et al. 2003) (see Fig. 5). A note on the chronostratigraphic usefulness of the Ordovician radiolarian merits special mention (Fig. 6) (Maletz 2011). These are associated with well-dated graptolite faunas (Maletz 2007) that allows very precise dating of

the radiolarian faunas and provides an opportunity to establish and calibrate the radiolarian biostratigraphy with various other macrofossils groups (Maletz 2011). An updated Permian and Triassic radiolarian biostratigraphy are provided in Tables 1 and 2 and representative radiolarian species through time are illustrated in Figs. 7, 8, 9, and 10.

124 Table 1 Permian radiolarian markers

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Geological History

Table 2 Triassic radiolarian markers

125

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Fig. 7 Representative Albaillellarian (1) and Spumellarian species. 1: Albaillellarian. 1: Albaillella Deflandre (Carboniferous); 2–14: Spumellarian. 2: Haplentactina (Devonian); 3 and 4: Paronaella Pessagno (Carboniferous– Cretaceous); 5 and 6: Alievium Pessagno (Triassic); 7: Capnuchosphera De Wever (Triassic); 8: Cenosphera (Eocene– Recent); 9: Ommatartus Haeckel (Miocene–Recent); 10: Cannartus Haeckel (Oligocene–Miocene); 11: Collosphera Müller (Miocene–Recent); 12: Actinomma Haeckel (Miocene–Recent);13: Amphirhoplanum Haeckel (Pliocene–Recent); 14: Saturnalis Haeckel (Pleistocene–Recent); 15–17: Nassellarian. 15–17: Dorcadospyris Haeckel (Eocene–Miocene); 15: Adult form; 16: Front view with cephalic constriction; 17: View from below

3

Geological History

127

Fig. 8 Representative Spumellarian species. 1: Heliosphaera clavate Hinde (Devonian); 2: Theodiscus hastus Hinde (Devonian); 3: Cenosphaera affinis Hinde (Devonian); 4: Lithocampe andersoni Campbell and Clarke (Cretaceous); 5: Saturnalis lateralis Campbell and Clarke (Cretaceous); 6: Hexadoridium magnificum Campbell and Clarke (Cretaceous); 7: Lithomelissa armata Campbell and Clarke (Cretaceous); 8: Trochodiscus nicholsoni Riist (Carboniferous); 9: Porodiscus (Trematodiscus) charlestonensis Campbell and Clarke (Eocene); 10: Calocyclas semipolita Campbell and Clarke (Eocene); 11: Tripilidium clavipes advena Campbell and Clarke (Eocene); 12: Roplacodictyum malagaense Campbell and Clarke (Miocene); 13: Saturolonche aculeata Campbell and Clarke (Miocene); 14: Pterocorys splendens Campbell and Clarke (Miocene)

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6 Radiolarians

3

Geological History

129

b Fig. 9 Representative Nassellarian species. 1 and 2: Mirifusus Pessagno (Jurassic–Cretaceous); 3: Saturniforma

Pessagno (Jurassic–Cretaceous); 4–6: Dictyomitra Zittel (Cretaceous); 5: Apical section; 6: Transverse section at the level of a diaphragm; 7: Holocryptocapsa Tan Sin Hok (Cretaceous); Axial section; 8 and 9: Theocampe Haeckel (Cretaceous–Recent), 8: Axial section; 9: Apical view of Cephalis; 10: Calocyclas Ehrenberg (Eocene); 11: Pterocanium Ehrenberg (Eocene–Recent); 12: Anthocyrtidium Haeckel (Oligocene–Recent); 13–15: Giraffospyris Haeckel (Eocene–Recent); 16: Zygocircus Butschli (Eocene–Recent); 17: Lychnocanoma Haeckel (Eocene–Recent); 18: Callimitra Haeckel (Eocene–Recent); 19: Phormostichoastus Haeckel (Oligocene–Recent); 20: Stichocorys Haeckel (Miocene–Pliocene); 21: Cyrtocapsa Haeckel (Oligocene–Miocene); 22: Peripyramis Haeckel (Oligocene–Recent); 23: Botryopyle Haeckel (Eocene–Recent); 24: Corocalyptra Haeckel (Pleistocene–Recent)

Fig. 10 Representative Nassellarian species. 1: Anthocyrtis mespihis Ehrenberg (Tertiary); 2: Lychocanium lucerna Ehrenberg (Tertiary); 3: Dictyomitra mespilus Ehrenberg (Tertiary); 4: Eucyrtidium elegans Ehrenberg (Tertiary); 5: Pterocodon compana Ehrenberg (Tertiary); 6: Podocyrtis schomburgi Ehrenberg (Tertiary); 7: Cyrtocalpis amphora Haeck (Recent); 8: Bothryocampe hexathalamia Haeck (Recent); 9: Petalospyris foreolata Ehrenberg (Tertiary)

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References Afanasieva, M. S., Amon, E. O., Agarkov, Yu V, & Boltovskoy, D. S. (2005). Radiolarians in the geological record. Paleontological Journal, 39(3), 135–392. Anderson, O. R. (1983). Radiolaria. New York, NY: Springer, 365p. Babcock, L. E., & Peng, S. (2007). Cambrian chronostratigraphy: current state and future plans. Palaeogeography, Palaeoclimatology, Palaeoecology, 254, 62–66. Boltovskoy, D., Kling, S. A., Takahashi, K., & Bjorklund, K. (2010). World atlas of distribution of living radiolaria. Palaeontologia Electronica, 13(3), 1–230. Braun, A., Chen, J., Waloszek, D., & Maas, A. (2007). First Early Cambrian Radiolaria. Geological Society, London, Special Publications 286(1), 143–149. Cao, W. C., Feng, Q. L., Feng, F. B., & Ling, W. (2014). Radiolarian Kalimnasphaera from the Cambrian Shuijingtuo Formation in South China. Marine Micropaleontology, 110(2), 3–7. Chang, S., Feng, Q., & Zhang, L. (2018). New siliceous microfossils from the Terreneuvian Yanjiahe formation, South China: The possible earliest radiolarian fossil record. Journal of Earth Science, 29(4), 912– 919. De Wever, P., Dumitrica, P., Caulet, J. P., Nigrini, C., & Caridroit, M. (2001). Radiolarians in the sedimentary record (p. 533). Amsterdam: Gordon and Breach Science Publishers. De Wever, P., O’Dogherty, L., Caridroit, M., Dumitrica, P., Guex, J., Nigrini, C., et al. (2003). Diversity of radiolarian families through time. Bulletin de la Société géologique de France, 174(5), 453–469. Dong, X., Knoll, A. H., & Lipps, J. R. (1997). Late Cambrian Radiolaria from Hunan, China. Journal of Paleontology, 71(5), 753–758. Geyer, G., & Landing, E. (2004). A unified lower–middle Cambrian chronostratigraphy for West Gondwana. Acta Geologica Polonica, 54, 179–218. Hao, Y. C., & Shu, D. G. (1987). The oldest well-preserved Phaecodaria (Radiolaria) from southern Shaanxi. Geoscience, 1, 301–310. Haq, B. U., & Boersma, A. (1998). Introduction to marine micropaleontology (2nd ed., pp. 376). Elsevier. Hurd, D. C., & Takahashi, K. (1983). On the estimation of minimum mechanical loss during an in situ biogenic silica dissolution experiment. Marine Micropaleontology, 7, 441–447. Lethiers, F. (1998). Evolution de la biosphère et événements géologiques. (p. 321). Paris: Gordon and Breach.

6 Radiolarians Maletz, J. (2011). Radiolarian skeletal structures and biostratigraphy in the early Palaeozoic (Cambrian– Ordovician). Palaeoworld, 20, 116–133. Maletz, J. (2007). The Ordovician Beothuka terranova (Radiolaria) assemblage in western Newfoundland. Paläontologische Zeitschrift, 81(1), 71–82. Maletz, J., & Bruton, D. L. (2007). Lower Ordovician (Chewtonian to Castlemainian) radiolarians of Spitsbergen. Journal of Systematic Palaeontology, 4, 245– 288. Maletz, J., & Bruton, D. L. (2008). The middle Ordovician Proventocitum procerulum radiolarian assemblage of Spitsbergen and its biostratigraphic correlation. Palaeontology, 51(5), 1181–1200. Noble, P. J., & Webby, B. D. (2009). Katian (Ordovician) radiolarians from the Malongulli Formation, New South Wales, Australia, a reexamination. Journal of Paleontology, 83, 548–561. Obut, O. T., & Iwata, K. (2000). Lower Cambrian Radiolaria from Gorny Altai (southern West Siberia). Lower Cambrian Radiolaria from the Gorny Altai (southern West Siberia). Journal of Geology and Geophysics 41 (Suppl.News of Paleontology and Stratigraphy Nos. 2–3), 33–37. Peng, S. (2003). Chronostratigraphic subdivision of the Cambrian in China. Geologica Acta, 1, 135–144. Petrushevskaya, M. G. (1981). Radiolarians of the Order Nassellaria of the World Ocean. Leningrad: Nauka. (in Russian). Takahashi, K., & Honjo, S. (1981). Vertical flux of Radiolaria: A taxon-quantitative sediment trap study from the western Tropical Atlantic. Micropaleontology, 27, 140–190. Westphal, A. (1976). Protozoa (325p). Glasgow: Blackie. White, R. D. (1986). Cambrian radiolaria from Utah. Journal of Paleontology, 60, 778–780. Won, M. Z., & Below, R. (1999). Cambrian Radiolaria from the Georgina Basin, Queensland, Australia. Micropaleontology, 45, 325–363. Won, M. Z., Iams, W. J., & Reed, K. M. (2007). Late Tremadocian radiolarian faunas and biostratigraphy of the Cow Head Group, western Newfoundland, Canada. Journal of the Korean Earth Science Society, 28(4), 497–540. Won, M. Z., Blodgett, R. B., & Nestor, V. (2002). Llandoverian (Early Silurian) radiolarians from the Road River Formation of East-Central Alaska and the new family Haplotaeniatumidae. Journal of Paleontology, 76(6), 941–964. Won, M. Z., & Iams, W. J. (2002). Late Cambrian radiolarian faunas and biostratigraphy of the Cow Head Group, western Newfoundland. Journal of Paleontology, 76, 1–33.

7

Marine Diatoms

1

Introduction

Diatoms are very small (10–200 lm) plant-like organisms (phytoplanktons) that float. Of all the algae phyla, diatoms are the most numerous, with *10,000 known species, inhabiting both marine (*75%) and fresh water and other habitats (*25%). Like plants, the diatoms photosynthesize sunlight (autotrophs), but unlike terrestrial plants their light absorbing pigments are brown, not green. As they are light-dependent (sunlight for photosynthesis), they generally live within the photic zone (i.e. depths b  c); it is narrower than the lath (Fig. 6(2)). 3.5.5 Wedge This element tapers at one end but overall, all three elements are nearly of the same size (Fig. 6(3)). 3.5.6 Petal/Petaloid Element This element also tapers on one end (like a petal of a flower) but is much broader, bigger, and thinner than the Wedge (Fig. 6(3)). 3.5.7 Ray This element also tapers on one end but is much elongated and wide (Fig. 6(3)). 3.5.8 Spine This element also tapers on one end (“spine-like”) and elongates, but is much narrower than a ray (Fig. 6(3)). 3.5.9 Granule This element is small and variable-shaped element. Example: the blanket elements of Helicosphaera and the spine-forming elements of Cretarhabdus.

3.6 Element Modifications 3.6.1 Kink It is characterized by an angular bend in the element (Fig. 6(4)). Example: Discorhabdus criotus Bown. 3.6.2 Offset It is the displacement of an element from the radial growth caused by a double kink (Fig. 6(4)). Example: Grantarhabdus coronadventis (Reinhardt).

3

Terminology for Heterococcoliths and Nannoliths

209

Fig. 6 Element terminology. Orientation of the three orthogonal axes (1). The element shapes (2–3) are a function of the orientation of these three axes. Element modifications (4–5), types of openings (6–8), and description of the parts of rimz (9–10). Modified after Young et al. (1997) and with permission from Dr. Jeremy Young (UK). See text for further explanation

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3.6.3 Node It is a block-shaped projection from the element (Fig. 6(5)). Example: Discoaster mediosus Bramlette and Sullivan. 3.6.4 Keel It is a lath-shaped projection from the element (Fig. 6(5)). 3.6.5 Ridge It is a rod-shaped projection that runs all along the element (Fig. 6(5)). Example: Pontosphaera multipora (Kamptner). 3.6.6 Tooth It is a rod- or wedge-shaped projection from the element (Fig. 6(5)). Example: Eprolithus floralis (Stradner).

3.7 Types of Openings 3.7.1 Hole This is an opening that runs in one of the elements (Fig. 6(6)). Example: Pemma basquense (Martini). 3.7.2 Slit It is an elongate perforation (Fig. 6(6)). Example: Gephyrocapsa ericsonii (McIntyre and Bé). 3.7.3 Perforation It is a small opening present between two or more elements (Fig. 6(6)). Example: Anthosphaera periperforata Kleijne. 3.7.4 Canal This is a narrow elongated opening within a coccolith or nannolith. Example: Nannoconus kamptneri Brönnimann. 3.7.5 Cavity This is a broad opening within a coccolith or a nannolith. Example: Polycostella beckmannii Thierstein. 3.7.6 Depression This is a pit on the surface of a coccolith or a nannolith. Example: Micula concava (Stradner).

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Calcareous Nannofossils

3.8 Element Curvature 3.8.1 Dextrogyre The elements curve to the right when traced radially outward (Fig. 6(7)). Example: Cyc1agelosphaera reinhardtii (Perch-Nielsen) Romein. 3.8.2 Laevogyre The elements curve to the left when traced radially outward (Fig. 6(8)). Example: Fasciculithus involutus Bramlette and Sullivan. 3.8.3 Straight The elements are not curved. 3.8.4 Rims This Is Largely Formed of Cyclic Structures Possessing High Rotational Symmetry (Fig. 6(9 and 10)).

3.9 Parts of Rims Each of these parts may be formed of a single cycle of elements, part of a cycle, or several cycles illustrated in Fig. 6(9 and 10).

3.9.1 Wall This is a subvertical structure that is not associated with shields (Muroliths) (Fig. 6(9)). The wall together with the shield is composed of several elements that vary from species to species. The Chiasmolithus eograndis Perch-Nielsen may have 60–100 elements each, whereas in Chiasmolithus bidens (Bramlette and Sullivan), the range is between 51 and 75 elements. 3.9.2 Flange It is the subhorizontal protrusion (in the outward-lateral direction) from the rim (Fig. 6 (9)). Example: Lophodolithus nascens Bramlette and Sullivan. 3.9.3 Collar It is the subvertical protrusion from rim (may occur on proximal or distal surfaces) (Fig. 6(9 and 10)). Example: Rhabdosphaera perlonga (Deflandre) Bramlette and Sullivan.

3

Terminology for Heterococcoliths and Nannoliths

3.9.4 Shield It is a broad (sub-) horizontal structure (Fig. 6 (10)). Example: Biscutum castrorum Black. 3.9.5 Tube It is the subvertical structure between two shields (Fig. 6(10)). 3.9.6 Crown It is the discontinuous/beaded collar. Example: Prinsius dimorphosus (Perch-Nielsen).

3.10 Directions on the Rim 3.10.1 Radial This is the direction on the surface of the baseplate perpendicular to its margin—inward, outward, toward from center, and away from center (Fig. 6(1)).

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3.10.2 Tangential This is the direction on the surface of the baseplate parallel to its margin (Fig. 6(1)). It is (as seen in the distal view) clockwise/dextral/ right or anticlockwise/sinistral/left senses of direction. 3.10.3 Vertical This is the direction perpendicular to the baseplate—Up/down distal-proximal directions (Fig. 6(1)). 3.10.4 Flare and Taper The divergence of orientation from horizontal/vertical in the radial direction (Fig. 6 (1); see also Fig. 7(1) and (3)). 3.10.5 Taper Surfaces The convergence upward, producing conical bodies (Fig. 7(1)).

Fig. 7 Element arrangements as seen in side view (1–9). 1–3: element arrangements based on the divergence of orientation from horizontal/vertical in the radial direction; 4–6: element arrangements based on the divergence from the horizontal in the tangential direction; 7–9: element arrangements based on the divergence from the horizontal from the radial direction. 10–12: types of sutures. 13–17: element arrangement in plan view showing different types of coccolith placement (13–17). Modified after Young et al. (1997) and with permission from Dr. Jeremy Young (UK). See text for further explanation

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3.10.6 Flare Surfaces The divergence upward, producing obconical/ funnel-shaped bodies (Fig. 7(3)). 3.10.7 Element Arrangement as Seen in Side View . 3.10.8 Imbrication This is the divergence from the horizontal in the tangential direction (Fig. 7(4) and (6)). 3.10.9 Anticlockwise/Clockwise Imbrication This is the offset of the upper part of element from the lower. Example: anticlockwise (Fig. 7 (9)): Coronosphaera Gaarder; clockwise (Fig. 7 (11)): Pontosphaera Lohmann. 3.10.10 Imbrication Angle This is the angle of contact-surface from the horizontal. There are two types, high angle with subvertical contact-surfaces and low angle with subhorizontal contact-surfaces. Example: Gephyrocapsa Kamptner. 3.10.11 Zeugoid Rim This is characterized by a rim that has high-angled imbrication but is without distinct shields. Example: Bownia Varol and Girgis.

3.11 Element Arrangement as Seen in Plan View 3.11.1 Obliquity This is the horizontal divergence from the radial direction (see Fig. 7(7–9)). Example: Calciopappus caudatus Gaarder and Ramsfjell. 3.11.2 Dextral/Sinistral Obliquity This is the deflection from the radial of the outer part of element relative to the inner part, as seen in distal view. A dextrally oblique cycle displays clockwise obliquity in distal view but anticlockwise obliquity in proximal view (Fig. 7(9)). Examples: anticlockwise obliquity (chirality; see Fig. 7(7))—Syracosphaera corolla Lecal;

10

Calcareous Nannofossils

clockwise obliquity (see Fig. 7(9))—Syracosphaera rotula Okada and McIntyre.

3.11.3 Butting These are elements with simple subradial sutures (Fig. 7(10)). Example: Braarudosphaera bigelowii (Gran and Braarud). 3.11.4 Interlocking These are elements with complex sutures (Fig. 7(11)). 3.11.5 Overlapping These are elements with low angle oblique sutures (Fig. 7(12)). The orientation of these crystal units is mostly radial and vertical but some are orthogonal (the latter arrangement gives chirality to the coccolith structure). The chirality is expressed in terms of imbrication and obliquity direction of individual elements (Fig. 5) which remains the same at the species level (Didymus and Young 1994). Details of the structures/terms mentioned above are further elaborated and explained below in Sect. 3, Terminology for Coccoliths and Nannoliths.

3.12 Coccolith Arrangement 3.12.1 Non-Overlapping The adjacent coccoliths are arranged with edges directly butting with each other, rather than overlapping. These types are either non-overlapping interlocking, where the adjacent coccoliths interlock or are non-overlapping noninterlocking where the adjacent coccoliths do not interlock (Figs. 7(13–14)). 3.12.2 Interlocking In this condition, the adjacent coccoliths interlock (Fig. 7(15)). 3.12.3 Overlapping In this condition, the adjacent coccoliths overlap (Fig. 7(16 and 17)). Both overlapping and interlocking patterns can occur in varied combinations.

4

4

Terms Used in Describing the Parts of a Holococcolith

Terms Used in Describing the Parts of a Holococcolith

213

4.4 Rim

4.1 Holococcolith

This is the marginal part best observed in cross-polarized light that typically has elements with radial c-axes (Fig. 8(6 and 7).

A coccolith that is built by many small-sized (