DOCSLIB.ORG

(Ediacaran) Rangeomorphs

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

THE PALAEOBIOLOGY OF AVALONIAN (EDIACARAN) RANGEOMORPHS Charlotte Guenevere Kenchington Selwyn College University of Cambridge December 2015 This dissertation is submitted for the degree of Doctor of Philosophy SUMMARY: THE PALAEOBIOLOGY OF AVALONIAN (EDIACARAN) RANGEOMORPHS CHARLOTTE G. KENCHINGTON The Earth has supported life for most of its 4.5 billion year history, but the first macroscopic organisms only appeared some 600 million years ago, in the Ediacaran. Their world was fundamentally different from the one we know today, and many aspects of their biology and ecology remain a mystery. The late Ediacaran fossil assemblages of Avalonia represent some of the oldest evidence for complex macroscopic life, and are dominated by rangeomorphs, a group characterised by their self-similar branching architecture. In this thesis, I investigate several aspects of the preservation, classification and ecology of these enigmatic deep marine organisms. The biotas of Charnwood Forest host several taxa which are new to science. Five of these are described here, and include two new genera, Orthiokaterna fordi gen. et sp. nov., and Undosyrus nemoralis gen. et sp. nov., and three new species: Primocandelabrum anatonos sp. nov., P. boytoni sp. nov., and P. katatonos sp. nov.. The Primocandelabrum species in particular encompass a great deal of variation in both branching characters and overall morphology. By using a novel multivariate statistical approach to analyse multiple characters in tandem, individual taxa can be discriminated from one another. Much of the observed variation is interpreted as intra-specific. This level of variation within a single taxon has not previously been recognised in rangeomorphs, and is likely attributable to (eco?)phenotypic rather than ontogenetic variability. Orthiokaterna displays eccentric branches, interpreted as a growth response to mechanical damage, reflecting a greater degree of growth plasticity than that recognised in other rangeomorphs, while Undosyrus had an external sheath, interpreted as modified rangeomorph elements serving a protective role. Even without knowing the phylogenetic relationships of rangeomorphs, it is possible to resolve key aspects of their palaeoecology. The response(s) of communities in Charnwood Forest and Newfoundland to both ambient disturbance and to more substantial events is investigated by combining detailed petrographic analysis of the host sediments with multivariate statistical techniques. I demonstrate that higher taxonomic diversity is correlated with low–intermediate physical disturbance; that upright taxa (e.g. Charnia) dominate surfaces which experienced small-scale, sub-lethal sedimentation events and comparably high background sediment input; and that flat-lying forms (e.g. Fractofusus) preferentially occur on surfaces with low sediment input. The population demographics of several taxa also show evidence of multimodality: in some (including Charnia and Primocandelabrum), bimodality was I induced by culling of part of an incumbent population by a substantial disturbance event, followed by re-colonisation; in others (e.g. Fractofusus), overlapping cohorts reflect non-continuous or pulsed reproduction. Disturbance (ambient and discrete events) demonstrably influenced community succession, with early-colonising taxa dominating horizons with low overall levels of disturbance, and those able to survive disturbance events dominating recovery populations and horizons with higher levels of disturbance. Based on their inferred life history traits and their environmental preferences, I propose a model of ecological succession for rangeomorph communities. II DECLARATION Declaration of Originality This dissertation is the result of my own work and includes nothing which is the outcome of work done in collaboration except as declared below and specified in the text. It is not substantially the same as any that I have submitted, nor is it being concurrently submitted for a degree or diploma or other qualification at the University of Cambridge or any other University or similar institution. Published work arising from the dissertation Parts of Chapter 3 are based on material presented in Kenchington & Wilby (2014), paper entitled Of time and taphonomy: preservation in the Ediacaran and published in The Paleontological Society Papers, volume 20. Parts of the interpretation in Chapter 9 (and Fig. 9.13) are based on work I published in collaboration with P.R. Wilby and R.L. Wilby (Wilby et al. 2015), paper entitled: Role of low intensity environmental disturbance in structuring the earliest (Ediacaran) macrobenthic tiered communities, Palaeogeography, Palaeoclimatology, Palaeoecology, volume 434. Figure 10.1 was published in Mitchell et al. 2015, paper entitled: Reconstructing the reproductive mode of an Ediacaran macro-organism, published in Nature, volume 524. Figure 10.3 was published in Liu et al. 2015a, paper entitled: Remarkable insights into the paleoecology of the Avalonian Ediacaran macrobiota, Gondwana Research, volume 27. Statement of Length This dissertation is within the prescribed length as defined by the Degree Committee for Earth Sciences and Geography. III IV CONTENTS SUMMARY: THE PALAEOBIOLOGY OF AVALONIAN (EDIACARAN) RANGEOMORPHS ....................................I DECLARATION ..................................................................................................................................... III FIGURES ..............................................................................................................................................XI TABLES .............................................................................................................................................XIII ACKNOWLEDGEMENTS .......................................................................................................................XIV 1. INTRODUCTION: THE EDIACARAN AND AVALONIA ...............................................................................1 1.1 Global context for life Ediacaran ......................................................................................... 1 1.1.1 Glaciations and oxygenation ...................................................................................3 1.2 Life in the Ediacaran ............................................................................................................ 3 1.2.1 Rangeomorphs ......................................................................................................... 5 1.2.2 Arboreomorphs....................................................................................................... 10 1.2.3 Discoidal forms ......................................................................................................10 1.2.4 Other taxa ...............................................................................................................10 1.3 Rangeomorph growth and functional morphology .............................................................11 1.4 The Ecology of Avalonian Rangeomorphs .........................................................................12 2. GEOLOGICAL CONTEXT FOR THE EDIACARAN OF AVALONIA ............................................................. 14 2.1 Ediacaran Stratigraphy of Avalonia ....................................................................................14 2.1.1 The Geological Setting of Charnwood Forest ........................................................14 2.1.1.1 Age constraints for Charnwood Forest ........................................................ 16 2.1.1.2 Fossil occurrences in Charnwood Forest .....................................................17 2.1.1.3 Detailed lithological analysis of the Bradgate Formation ............................19 2.1.2 The Geological Setting of the Ediacaran of Newfoundland .................................. 20 2.1.2.1 Age constraints for Newfoundland .............................................................. 24 2.1.2.2 Deep-water fossil occurrences in Newfoundland ........................................ 25 2.2 Comparing the Newfoundland and Charnwood Forest successions. ........................25 3. THE TAPHONOMY OF AVALONIAN RANGEOMORPHS ........................................................................... 27 3.1. Introduction ....................................................................................................................... 27 3.2 Metamorphism .................................................................................................................... 28 3.3. Mouldic preservation: mechanisms and mineralisation .................................................... 28 3.3.1 The “death mask” hypothesis .................................................................................29 3.3.2 The timing of pyritisation: new evidence from Charnwood Forest and Newfoundland ................................................................................................................. 30 3.3.3 Phosphatisation ...................................................................................................... 33 3.3.4 Discussion .............................................................................................................. 36 3.3.4.1 The location of pyritisation and variability of preservation .........................36 3.3.4.2 The timing of pyritisation ........................................................................... 37 V 3.3.4.3 The importance of different mineral phases in Avalonian
Recommended publications
  • Integrative and Comparative Biology Integrative and Comparative Biology, Volume 58, Number 4, Pp

    Integrative and Comparative Biology Integrative and Comparative Biology, Volume 58, Number 4, Pp

    Integrative and Comparative Biology Integrative and Comparative Biology, volume 58, number 4, pp. 605–622 doi:10.1093/icb/icy088 Society for Integrative and Comparative Biology SYMPOSIUM INTRODUCTION The Temporal and Environmental Context of Early Animal Evolution: Considering All the Ingredients of an “Explosion” Downloaded from https://academic.oup.com/icb/article-abstract/58/4/605/5056706 by Stanford Medical Center user on 15 October 2018 Erik A. Sperling1 and Richard G. Stockey Department of Geological Sciences, Stanford University, 450 Serra Mall, Building 320, Stanford, CA 94305, USA From the symposium “From Small and Squishy to Big and Armored: Genomic, Ecological and Paleontological Insights into the Early Evolution of Animals” presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3–7, 2018 at San Francisco, California. 1E-mail: [email protected] Synopsis Animals originated and evolved during a unique time in Earth history—the Neoproterozoic Era. This paper aims to discuss (1) when landmark events in early animal evolution occurred, and (2) the environmental context of these evolutionary milestones, and how such factors may have affected ecosystems and body plans. With respect to timing, molecular clock studies—utilizing a diversity of methodologies—agree that animal multicellularity had arisen by 800 million years ago (Ma) (Tonian period), the bilaterian body plan by 650 Ma (Cryogenian), and divergences between sister phyla occurred 560–540 Ma (late Ediacaran). Most purported Tonian and Cryogenian animal body fossils are unlikely to be correctly identified, but independent support for the presence of pre-Ediacaran animals is recorded by organic geochemical biomarkers produced by demosponges.
  • Reptile Checklist for Leicestershire and Rutland

    Reptile Checklist for Leicestershire and Rutland

    Reptile Checklist for Leicestershire and Rutland Compiled in 2016 by Andrew Heaton, County Recorder for Amphibians and Reptiles in Vice-County 55 (Leicestershire & Rutland) R1. Slow-worm Anguis fragilis Native. Uncommon, with few scattered records in Charnwood, West Leicestershire and Rutland (the main concentration, if any, being Charnwood Forest). This legless lizard, being rather elusive, may possibly be under- recorded rather than rare – elsewhere around the Midlands, it is frequently found in urban areas (gardens and allotments). There may have been a decline since recording began. RDB species. Slow-worm (Anguis fragilis) Viviparous Lizard (Lacerta vivipara) 5 5 4 4 3 3 2 2 1 1 SK TF SK TF 9 9 8 8 7 7 SP 2 3 4 5 6 7 8 9 TL 1 SP 2 3 4 5 6 7 8 9 TL 1 R2. Common Lizard Zootoca vivipara Native. Uncommon; records are concentrated in the heathy habitats of Charnwood Forest and the Moira area of North West Leicestershire, and in the drier habitats of East Rutland. Elsewhere, they are rather scarce, but, pleasingly, new sites seem to keep turning up. Confirmation of the presence of lizards outside Charnwood Forest was only made in comparatively recent years (since the 1960s). RDB species. R3 Sand Lizard Lacerta agilis Native to Britain (but probably not in Leicestershire). Native to heaths and sand dunes in south-central England. Reported in the Victoria County History of Leicestershire (1907), as formerly present, in the 1840s, (in Charnwood?), though rare. There is no firm evidence for this (and the VCH author appears sceptical).
  • Contributions to the Neoproterozoic Geobiology

    Contributions to the Neoproterozoic Geobiology

    Contributions to the Neoproterozoic Geobiology Bing Shen Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Department of Geosciences Shuhai Xiao (Chair) Robert Bodnar Michal Kowalewski J. Fred Read November 29, 2007 Blacksburg, Virginia Key words: Neoproterozoic, Ediacaran, Ediacara fossils, China, Disparity, Sulfur isotope, Carbon isotope Copyright 2007, Bing Shen Contributions to the Neoproterozoic Geobiology Bing Shen Abstract This thesis makes several contributions to improve our understanding of the Neoproterozoic Paleobiology. In chapter 1, a comprehensive quantitative analysis of the Ediacara fossils indicates that the oldest Ediacara assemblage—the Avalon assemblage— already encompassed the full range of Ediacara morphospace. A comparable morphospace range was occupied by the subsequent White Sea and Nama assemblages, although it was populated differently. In contrast, taxonomic richness increased in the White Sea assemblage and declined in the Nama assemblage. The Avalon morphospace expansion mirrors the Cambrian explosion, and both may reflect similar underlying mechanisms. Chapter 2 describes problematic macrofossils collected from the Neoproterozoic slate of the upper Zhengmuguan Formation in North China and sandstone of the Zhoujieshan Formation in Chaidam. Some of these fossils were previously interpreted as animal traces. Our study of these fossils recognizes four genera and five species. None of these taxa can be interpreted as animal traces. Instead, they are problematic body fossils of unresolved phylogenetic affinities. Chapter 3 reports stable isotopes of the Zhamoketi cap dolostone atop the Tereeken diamictite in the Quruqtagh area, eastern Chinese Tianshan. Our new data indicate that carbonate associated sulfate (CAS) abundance decreases rapidly in the basal 34 cap dolostone and δ SCAS composition varies between +9‰ and +15‰ in the lower 2.5 34 m.
  • Lessons from the Fossil Record: the Ediacaran Radiation, the Cambrian Radiation, and the End-Permian Mass Extinction

    Lessons from the Fossil Record: the Ediacaran Radiation, the Cambrian Radiation, and the End-Permian Mass Extinction

    OUP CORRECTED PROOF – FINAL, 06/21/12, SPi CHAPTER 5 Lessons from the fossil record: the Ediacaran radiation, the Cambrian radiation, and the end-Permian mass extinction S tephen Q . D ornbos, M atthew E . C lapham, M argaret L . F raiser, and M arc L afl amme 5.1 Introduction and altering substrate consistency ( Thayer 1979 ; Seilacher and Pfl üger 1994 ). In addition, burrowing Ecologists studying modern communities and eco- organisms play a crucial role in modifying decom- systems are well aware of the relationship between position and enhancing nutrient cycling ( Solan et al. biodiversity and aspects of ecosystem functioning 2008 ). such as productivity (e.g. Tilman 1982 ; Rosenzweig Increased species richness often enhances ecosys- and Abramsky 1993 ; Mittelbach et al. 2001 ; Chase tem functioning, but a simple increase in diversity and Leibold 2002 ; Worm et al. 2002 ), but the pre- may not be the actual underlying driving mecha- dominant directionality of that relationship, nism; instead an increase in functional diversity, the whether biodiversity is a consequence of productiv- number of ecological roles present in a community, ity or vice versa, is a matter of debate ( Aarssen 1997 ; may be the proximal cause of enhanced functioning Tilman et al. 1997 ; Worm and Duffy 2003 ; van ( Tilman et al. 1997 ; Naeem 2002 ; Petchey and Gaston, Ruijven and Berendse 2005 ). Increased species rich- 2002 ). The relationship between species richness ness could result in increased productivity through (diversity) and functional diversity has important 1) interspecies facilitation and complementary implications for ecosystem functioning during resource use, 2) sampling effects such as a greater times of diversity loss, such as mass extinctions, chance of including a highly productive species in a because species with overlapping ecological roles diverse assemblage, or 3) a combination of biologi- can provide functional redundancy to maintain cal and stochastic factors ( Tilman et al.
  • Environmental Risk Assessment March 2021

    Environmental Risk Assessment March 2021

    Environmental Risk Assessment March 2021 Client: Iona Capital Limited Document Reference: HC1671-06 Black Brook CHP Limited REPORT SCHEDULE Operator: Black Brook CHP Limited Client: Iona Capital Limited Project Title: Black Brook CHP Limited MCP Facility Permit Application Document Title: Environmental Risk Assessment Document Reference: HC1671-06 Report Status: Final 2.0 Project Directors: Joanna Holland AUTHOR DATE Jo Chapman 28th January 2021 REVIEWER Joanna Holland 1st February 2021 REVISION HISTORY DATE COMMENTS APPROVED Final Version 1.0 1st February 2021 For Client Review Julia Safiullina Final Version 1.1 23rd February 2021 For Submission to EA Julia Safiullina Final Version 2.0 24th March 2021 For Client Review and Submission to EA Julia Safiullina DISCLAIMER This report has been prepared by H&C Consultancy Ltd with all reasonable skill, care and diligence. It has been prepared in accordance with instructions from the client and within the terms and conditions agreed with the client. The report is based on information provided by the Client and our professional judgment at the time this report was prepared. The report presents H&C Consultancy’s professional opinion and no warranty, expressed or implied, is made. This report is for the sole use of the Client and the Operator and H&C Consultancy Ltd shall not be held responsible for any user of the report or its content for any other purpose other than that which it was prepared and provided to the client. H&C Consultancy accepts no liability to third parties. HC1671-06 Environmental Risk Assessment H&C Consultancy Ltd Black Brook CHP Limited ENVIRONMENTAL RISK ASSESSMENT 1.
  • Mcmenamin FM

    Mcmenamin FM

    The Garden of Ediacara • Frontispiece: The Nama Group, Aus, Namibia, August 9, 1993. From left to right, A. Seilacher, E. Seilacher, P. Seilacher, M. McMenamin, H. Luginsland, and F. Pflüger. Photograph by C. K. Brain. The Garden of Ediacara • Discovering the First Complex Life Mark A. S. McMenamin C Columbia University Press New York C Columbia University Press Publishers Since 1893 New York Chichester, West Sussex Copyright © 1998 Columbia University Press All rights reserved Library of Congress Cataloging-in-Publication Data McMenamin, Mark A. The garden of Ediacara : discovering the first complex life / Mark A. S. McMenamin. p. cm. Includes bibliographical references and index. ISBN 0-231-10558-4 (cloth) — ISBN 0–231–10559–2 (pbk.) 1. Paleontology—Precambrian. 2. Fossils. I. Title. QE724.M364 1998 560'.171—dc21 97-38073 Casebound editions of Columbia University Press books are printed on permanent and durable acid-free paper. Printed in the United States of America c 10 9 8 7 6 5 4 3 2 1 p 10 9 8 7 6 5 4 3 2 1 For Gene Foley Desert Rat par excellence and to the memory of Professor Gonzalo Vidal This page intentionally left blank Contents Foreword • ix Preface • xiii Acknowledgments • xv 1. Mystery Fossil 1 2. The Sand Menagerie 11 3. Vermiforma 47 4. The Nama Group 61 5. Back to the Garden 121 6. Cloudina 157 7. Ophrydium 167 8. Reunite Rodinia! 173 9. The Mexican Find: Sonora 1995 189 10. The Lost World 213 11. A Family Tree 225 12. Awareness of Ediacara 239 13. Revenge of the Mole Rats 255 Epilogue: Parallel Evolution • 279 Appendix • 283 Index • 285 This page intentionally left blank Foreword Dorion Sagan Virtually as soon as earth’s crust cools enough to be hospitable to life, we find evidence of life on its surface.
  • Rangeomorph Classification Schemes and Intra-Specific Variation: Are All

    Rangeomorph Classification Schemes and Intra-Specific Variation: Are All

    Downloaded from http://sp.lyellcollection.org/ by guest on September 23, 2021 Rangeomorph classification schemes and intra-specific variation: are all characters created equal? CHARLOTTE G. KENCHINGTON1,2* & PHILIP R. WILBY3 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK 2Present address: Department of Earth Sciences, Memorial University of Newfoundland, Prince Philip Drive, St John’s, NL, A1B 3X5, Canada 3British Geological Survey, Environmental Science Centre, Nicker Hill, Keyworth, Nottingham NG12 5GG, UK *Correspondence: [email protected] Abstract: Rangeomorphs from the Ediacaran of Avalonia are among the oldest known complex macrofossils and our understanding of their ecology, ontogeny and phylogenetic relationships relies on accurate and consistent classification. There are a number of disparate classification schemes for this group, which dominantly rely on a combination of their branching characters and shape metrics. Using multivariate statistical analyses and the diverse stemmed, multifoliate rangeomorphs in Charnwood Forest (UK), we assess the taxonomic usefulness of the suite of char- acters currently in use. These techniques allow us to successfully discriminate taxonomic groupings without a priori assumptions or weighting of characters and to document a hitherto unrecognized level of variation within single taxonomic groups. Variation within the currently defined genus Pri- mocandelabrum is too great to be realistically assigned to different species and may instead reflect primary character diversity, ontogenetic changes in character state or ecophenotypic variability. Its recognition cautions against generic-level diagnoses based on single differences in character state and will be crucial in understanding the mode of growth of these enigmatic organisms. Supplementary material: Data tables, definition of the characters used in the analyses, and detailed descriptions and breakdowns of methods and results are available at https://doi.org/10.
  • Back Matter (PDF)

    Back Matter (PDF)

    Index Acraman impact ejecta layer 53–4, 117, 123, 126–9, Aspidella 130–2, 425–7 controversy 300, 301–3, 305 acritarchs ecology 303 Amadeus and Officer Basins 119 synonyms 302 biostratigraphy 115–25, 130–2 Australia Australian correlations 130–2 Acraman impact ejecta layer 53–4, 117, 123, 126–9, composite zonation scheme 119, 131, 132 130–2, 425–7 India 318–20 carbon isotope chemostratigraphy 126–9 Ireland 289 correlations of Ediacaran System and Period 18, Spain 232 115–35 sphaeromorphid 324 Marinoan glaciation 53–4, 126 Adelaide, Hallett Cove 68 Australia, Ediacaran System and Period Adelaide Rift Complex 115–22, 425 Bunyeroo–Wonoka Formation transition correlations with Officer Basin 127 137–9, 426 dating (Sr–Rb) 140 Centralian Superbasin 118, 125 generalized time–space diagram, correlations composite zonation scheme 131 between tectonic units 120 correlation methods and results 125–32 location maps 116, 118 time–space diagram 120 SE sector cumulative strata thickness 139 Vendian climatic indicators 17 stratigraphic correlation with Officer Basin 127 See also Adelaide Rift Complex; Flinders Ranges Stuart Shelf drill holes, correlations 117 Avalonian assemblages, Newfoundland 237–57, Sturtian (Umberatana) Group 116, 138 303–7, 427 Umberatana Group 116, 138 Africa backarc spreading, Altenfeld Formation 44–5, 47–8 Vendian climatic indicators 17 Baliana–Krol Group, NW Himalaya 319 see also Namibia Barut Formation, Iran 434 Aldanellidae 418 Bayesian analysis algal metaphyta, White Sea Region 271–4 eumetazoans 357–9 algal microfossils, White
  • A Rich Ediacaran Assemblage from Eastern Avalonia: Evidence of Early

    A Rich Ediacaran Assemblage from Eastern Avalonia: Evidence of Early

    Publisher: GSA Journal: GEOL: Geology Article ID: G31890 1 A rich Ediacaran assemblage from eastern Avalonia: 2 Evidence of early widespread diversity in the deep ocean 3 [[SU: ok? need a noun]] 4 Philip R. Wilby, John N. Carney, and Michael P.A. Howe 5 British Geological Survey, Keyworth, Nottingham NG12 5GG, UK 6 ABSTRACT 7 The Avalon assemblage (Ediacaran, late Neoproterozoic) constitutes the oldest 8 evidence of diverse macroscopic life and underpins current understanding of the early 9 evolution of epibenthic communities. However, its overall diversity and provincial 10 variability are poorly constrained and are based largely on biotas preserved in 11 Newfoundland, Canada. We report coeval high-diversity biotas from Charnwood Forest, 12 UK, which share at least 60% of their genera in common with those in Newfoundland. 13 This indicates that substantial taxonomic exchange took place between different regions 14 of Avalonia, probably facilitated by ocean currents, and suggests that a diverse deepwater 15 biota that had a probable biogeochemical impact may already have been widespread at 16 the time. Contrasts in the relative abundance of prostrate versus erect taxa record 17 differential sensitivity to physical environmental parameters (hydrodynamic regime, 18 substrate) and highlight their significance in controlling community structure. 19 INTRODUCTION 20 The Ediacaran (late Neoproterozoic) Avalon assemblage (ca. 578.8–560 Ma) 21 preserves the oldest evidence of diverse macroorganisms and is key to elucidating the 22 early radiation of macroscopic life and the assembly of benthic marine communities Page 1 of 15 Publisher: GSA Journal: GEOL: Geology Article ID: G31890 23 (Clapham et al., 2003; Van Kranendonk et al., 2008).
  • Retallack 2014 Newfoundland Ediacaran

    Retallack 2014 Newfoundland Ediacaran

    Downloaded from gsabulletin.gsapubs.org on May 2, 2014 Geological Society of America Bulletin Volcanosedimentary paleoenvironments of Ediacaran fossils in Newfoundland Gregory J. Retallack Geological Society of America Bulletin 2014;126, no. 5-6;619-638 doi: 10.1130/B30892.1 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geological Society of America Bulletin Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes © 2014 Geological Society of America Downloaded from gsabulletin.gsapubs.org on May 2, 2014 Volcanosedimentary paleoenvironments of Ediacaran fossils in Newfoundland Gregory J.
  • Fossils, Feeding, and the Evolution of Complex Multicellularity

    Fossils, Feeding, and the Evolution of Complex Multicellularity

    Fossils, Feeding, and the Evolution of Complex Multicellularity The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Knoll, Andrew H., and Daniel J.G. Lahr. 2016. "Fossils, feeding, and the evolution of complex multicellularity." In Multicellularity, Origins and Evolution, The Vienna Series in Theoretical Biology, eds. Karl J. Niklas and Stuart A. Newman. Cambridge, MA: MIT Press. Published Version https://mitpress.mit.edu/books/multicellularity Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:34390340 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP Fossils, Feeding, and the Evolution of Complex Multicellularity Andrew H. Knoll and Daniel J. G. Lahr Andrew H. Knoll Department of Organismic and Evolutionary Biology, Harvard University Daniel J.G. Lahr Department of Zoology, Institute of Biosciences, University of São Paulo The evolution of complex multicellularity is commonly viewed as a series of genomic events with developmental consequences. It is surely that, but a focus on feeding encourages us to view it, as well, in terms of functional events with ecological consequences. And fossils remind us that these events are also historical, with environmental constraints and consequences. Several definitions of complex multicelluarity are possible; here we adopt to view that complex multicellular organisms are those with tissues or organs that permit bulk nutrient and gas transport, thereby circumventing the limitations of diffusion (Knoll, 2011).
  • Great Canadian Lagerstätten 6. Mistaken Point Ecological Reserve, Southeast Newfoundland Alexander G

    Great Canadian Lagerstätten 6. Mistaken Point Ecological Reserve, Southeast Newfoundland Alexander G

    Document generated on 10/01/2021 8:20 a.m. Geoscience Canada Journal of the Geological Association of Canada Journal de l’Association Géologique du Canada Great Canadian Lagerstätten 6. Mistaken Point Ecological Reserve, Southeast Newfoundland Alexander G. Liu and Jack J. Matthews Volume 44, Number 2, 2017 Article abstract Mistaken Point Ecological Reserve (MPER) World Heritage Site, on the URI: https://id.erudit.org/iderudit/1040786ar southeastern coast of Newfoundland, Canada, is one of the foremost global Ediacaran fossil localities. MPER contains some of the oldest known See table of contents assemblages of the softbodied Ediacaran macrobiota, and its fossils have contributed significantly to Ediacaran paleobiological research since their initial discovery in 1967. Preservation of multiple in situ benthic Publisher(s) paleocommunities, some comprising thousands of specimens, has enabled research into Ediacaran paleoecology, ontogeny, taphonomy, taxonomy and The Geological Association of Canada morphology, offering insights into the possible phylogenetic positions of Ediacaran taxa within the tree of life. Meanwhile, a thick and continuous ISSN geological record enables the fossils to be placed within a wellresolved temporal and paleoenvironmental context spanning an interval of at least 10 0315-0941 (print) million years. This article reviews the history of paleontological research at 1911-4850 (digital) MPER, and highlights key discoveries that have shaped global thinking on the Ediacaran macrobiota. Explore this journal Cite this article Liu, A. G. & Matthews, J. J. (2017). Great Canadian Lagerstätten 6. Mistaken Point Ecological Reserve, Southeast Newfoundland. Geoscience Canada, 44(2), 63–76. All Rights Reserved © The Geological Association of Canada, 2017 This document is protected by copyright law.