ichnia 2012 abstract book. the 3rd international congress on ichnology

Abstract Book

ICHNIA 20129 - 24 August, 2012St. John’s, Canada

The 3rd International Congress on Ichnology

Organizing Committee:

Duncan McIlroy Richard CallowSuzanne Dufour Liam Herringshaw

ICHNIA

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ICHNIA 2012The 3rd International Congress on Ichnology9 - 24 August, 2012Memorial University of NewfoundlandSt. John’s, Canada

Organizing Committee:

Duncan McIlroy Richard CallowSuzanne Dufour Liam Herringshaw

Abstract Book

Thank You to our Sponsors:

Ichnia 2012 St. John’s, Newfoundland ‐ Contents

i

TABLE OF CONTENTS

ICHNIA 2012 CONFERENCE SCHEDULE

1

ABSTRACTS (ALPHABETICAL BY FIRST AUTHOR’S LAST NAME) PABLO JOAQUIN ALONSO, LUIS ALBERTO BUATOIS AND CARLOS OSCAR LIMARINO 7 Postglacial Ichnofaunas of Western Gondwana: An example from the upper

Carboniferous Hoyada Verde Formation of Argentina

DAVID ARPAD, MAGDOLNA HORVATH AND ROZALIA FODOR 8 Ichnology of Early Miocene Shallow‐Marine Sediments in the southern Nograd Basin,

North Hungary

KORHAN AYRANCI, JAMES A. MACEACHERN AND SHAHIN E. DASHTGARD 9 Biology and Neoichnology of the Delta Front of the Asymmetrical Fraser River Delta,

British Columbia, Canada

KORHAN AYRANCI AND SHAHIN E. DASHTGARD 10 Infaunal Holothurians of the Fraser River Delta: Their Traces and Distributions

MAŁGORZATA BEDNARZ AND DUNCAN MCILROY 11 The Palaeobiological Implications of 3D Reconstructions of Chondrites isp.

ZAIN BELAÚSTEGUI, JORDI M. DE GIBERT, JAMES H. NEBELSICK, ROSA DOMÈNECH, JORDI MARTINELL, IMRAN A.

RAHMAN AND SAMUEL ZAMORA 12

Hard‐Substrate Oases for Bivalve Colonization: Gastrochaenids in Dead Clypeasteroid Tests (Miocene, E Spain)

CHRIS BOYD AND DUNCAN MCILROY 13 Three Dimensional Morphological Modelling of Parathaentzschelinia isp.

LUIS A. BUATOIS AND M. GABRIELA MÁNGANO 14 Ichnodiversity and Ichnodisparity: Significance and Caveats

ILYA V. BUYNEVICH, R. TSADOK, M. RUBIN, J. BENNER, J.A. AUSTIN, JR., S.T. HASIOTIS, D.F. COLEMAN, R.D.

BALLARD, Z. BEN AVRHAM AND Y. MAKOVSKY 15

Bathyal Neoichnology With Remotely Operated Vehicles (ROVs): Fish Traces and Sediment Resuspension in the Eastern Mediterranean Sea

ILYA V. BUYNEVICH, SERGEY KADURIN, IGOR LOSEV, DMITRY KOLESNIK, IGOR DARCHENKO AND EVGENY LARCHENKOV

16

Occurrence and Preservation Potential of Modern Vertebrate Traces in Contrasting Geological Settings Along the Northwestern Black Sea Coast, Ukraine


ii

ILYA V. BUYNEVICH, ANDREW BENTLEY, DAVID BUSTOS, DOUGLAS JEROLMACK AND GARY KOCUREK 17 Georadar Signatures of Vertebrate Burrows Across a Gypsum Dunefield:

White Sands, New Mexico, USA

RICHARD H.T. CALLOW, DUNCAN MCILROY, BEN KNELLER AND MASON DYKSTRA 18 Ichnology of Continental Slope‐channel Systems: Biological, Sedimentological and

Petroleum Geological Perspectives

NOELIA CARMONA, CONSTANZA BOURNOD, JUAN JOSÉ PONCE, DIANA CUADRADO AND ANDREAS WETZEL 20 Microbial Mats and Their Role in the Preservation of Vertebrate Footprints: Modern

Tracks and Their Fossil Counterparts

NOELIA B. CARMONA, LUIS A. BUATOIS, M. GABRIELA MÁNGANO, RICHARD G. BROMLEY, JUAN JOSÉ PONCE AND E. BELLOSI

21

Ichnology of Marine Deposits from Patagonia (Southern Argentina): the Role of the Modern Evolutionary Fauna in Neogene Infaunal Ecosystems

KAREN CHIN 22 Burrow/Coprolite Associations: Anomalous or Expected?

H. ALLEN CURRAN 23 Bahamian Ophiomorpha Heaven: Pleistocene Ichnology of Harry Cay, Little Exuma

SUDIPTA DASGUPTA, LUIS A. BUATOIS AND MARIA GABRIELA MÁNGANO 24 Sedimentology and Ichnology of the Palaeo‐Orinoco Shelf‐Edge Delta in the Pliocene

Mayaro Formation of Trinidad

JORDI M. DE GIBERT 25 The Roots of Modern Shallow‐Marine Soft‐Bottom Benthic Communities:

An Ichnological Approach

JORDI M. DE GIBERT,H. ALLEN CURRAN, RENATA G. NETTO, FRANCISCO W. TOGNOLI AND ZAIN BELAÚSTEGUI 26 Burrowing Capabilities of Juvenile Thalassinideans: Paleobiological Significance of

Ophiomorpha puerilis from the Pleistocene of the Bahamas and Southern Brazil

HURIYE DEMIRCAN AND DOĞAN USTA 27 Early Ordovician Trace Fossils from the Amanos Mountais (NE Osmaniye, SE Anatolia)

ANDREI DRONOV 28 Trace Fossils from the Ordovician Cool‐water Carbonates of St. Petersburg Region, Russia

SUZANNE C. DUFOUR

AND REBECCA T. BATSTONE 29 The Sulphide Mining Activities of Chemosymbiotic Thyasirid Bivalves

A. A. EKDALE AND JORDI M. DE GIBERT 30 The Ups and Downs of Farming in a Tectonically Active Basin: Late Miocene Agrichnia in

the Vera Basin of Southeastern Spain


iii

MAGDY EL‐HEDENY, ABDEL GALIL HEWAIDY AND KHALID AL KAHTANY 31 Shallow Marine Trace Fossils from the Callovian‐Oxfordian Tuwaiq Mountain Limestone

and Hanifa Formations, Central Saudi Arabia

HAYLEY ESSEX, DORRIK STOW AND IODP 339 SHIPBOARD SCIENTIFIC PARTY 32 The Ichnology of Contourites: Examples from the Gulf of Cadiz

DIANA ELIZABETH FERNÁNDEZ AND PABLO JOSÉ PAZOS 33 Nereites‐like Trace Fossils in Lower Cretaceous Marginal Marine Environments from

Patagonia: Preservational Variants and Ichnotaxonomic Discussion

DIANA ELIZABETH FERNÁNDEZ AND PABLO JOSÉ PAZOS 34 Enhanced Preservation of Delicate Arthropod Trackways by Microbial Mat

Biostabilisation in a Cretaceous Marginal‐Marine Setting from Patagonia: A Preliminary Study

ROZALIA FODOR AND DAVID ARPAD 35 Ichnology of an Early Miocene Siliciclastic Succession (Dédestapolcsány, North‐Hungary)

ROSANA GANDINI AND RENATA G. NETTO 36 Ophiomorpha from Lower Permian Sandstones of Southern Brazil

MICHAEL GARTON AND DUNCAN MCILROY 37 Feeding Trails and Mass Migrations: Large Arthropod Traces from the Early Cambrian of

North‐West Scotland

V. GAUR AND V.S. PARIHAR 38 New Record of Trace Fossils from the Nagaur Sandstone of Marwar Supergroup, Dulmera

Area, District‐Bikaner, Rajasthan, India

STACEY GIBB, S. GEORGE PEMBERTON AND BRIAN D.E. CHATTERTON 39 A Trace in Every Port: Rusophycus carleyi Group

SHWETA S. GURAV

AND KANTIMATI G. KULKARNI 40 Schaubcylindrichnus in the Assilina Limestone Member (Ypresian) Naredi Formation,

Kachchh, India

DARIO HARAZIM, DUNCAN MCILROY, NICOLAS EDWARDS, ROY WOGELIUS AND UWE BERGMANN 41 The Biogeochemical Effect of Bioturbation: A Perspective from the Rock Record

DANIEL HEMBREE, JARED BOWEN, ANGELINE CATENA AND NICOLE DZENOWSKI 42 Improving the Interpretation of Continental Ichnofossils Through Experimental

Neoichnology of Modern Soil Animals

LIAM HERRINGSHAW AND DUNCAN MCILROY 43 The Fossil Record of Bioirrigation


iv

KENTARO IZUMI 44 Geochemical Analyses of the Trace Fossil Phycosiphon incertum from Lower Jurassic Shelf

Deposits: Implications for the Mineral Selection Preferences of its Tracemaker

SÖREN JENSEN, LUIS A. BUATOIS AND M. GABRIELA MÁNGANO 45 Testing for Palaeogeographical Patterns in the Distribution of Cambrian Trace Fossils

SÖREN JENSEN, TEODORO PALACIOS, CARLOS NETO DE CARVALHO AND PEDRO MARTINS

46 Trace Fossils and Acritarchs from the Colorada Formation (Upper Ordovician?), Ossa‐

Morena Zone, SW Iberian Peninsula

HENDRIK KLEIN AND SPENCER G. LUCAS 47 The Late Triassic Phytosaur Ichnotaxon Apatopus lineatus (Bock, 1952) and Other

Footprints That Demonstrate Parallel Evolution of the Semi‐aquatic Lifestyle in Archosaurs

DIRK KNAUST, MICHAŁ WARCHOŁ AND IAN KANE 48 Ichnology in Reservoir Characterization of Turbidites: Lessons Learned from Outcrop

Studies

DIRK KNAUST 49 Trace Fossil Classification: Where are We? Can We do it Better? Does it Matter?

RICHARD J. KNECHT AND JACOB S. BENNER 50 Contemplating Cubichnia: No Time to Rest

VERÓNICA KRAPOVICKAS, MARÍA GABRIELA MÁNGANO AND CLAUDIA A. MARSICANO 52 Continental Ichnofacies Models: The Role of Tetrapod Tracks

DESMOND WILLIAM KRUMMECK 53 Large Burrows and Paleoenvironmental Reconstructions of the Early Triassic Katberg

Formation, South Eastern Main Karoo Basin, South Africa

KANTIMATI G. KULKARNI AND VIDYADHAR D. BORKAR 54 Diplocraterion Torell from a Lower Cretaceous Prograding Delta Sequence, Kachchh, India

VERONIKA KUSHLINA AND ANDREI DRONOV 55 First Record of Protichnites in the Lower Cambrian of St. Petersburg Region, NW Russia

ABDELOUAHED LAGNAOUI, SEBASTIAN VOIGT, HENDRIK KLEIN, HAFID SABER , JÖRG W. SCHNEIDER AND

ABDELKBIR HMINNA 56

Late Paleozoic ‐ Early Mesozoic Tetrapod Ichnoassemblages from Morocco: Results and Perspectives

MARY LEAMAN AND DUNCAN MCILROY 57

Three Dimensional Morphology of Diplocraterion


v

SPENCER G. LUCAS AND HENDRIK KLEIN 58 Triassic Time and Tetrapod‐Body‐Fossil and Footprint Biostratigraphy and Biochronology

ALEXANDER G. LIU1, DUNCAN MCILROY2 AND MARTIN D. BRASIER3 59 Metazoan locomotion at ~565 Ma: Detailed analysis of surface traces from the late

Ediacaran Mistaken Point Formation, Newfoundland

M. GABRIELA MÁNGANO, RICHARD G. BROMLEY, DAVID A.T. HARPER, ARNE T. NIELSEN, M. PAUL SMITH AND

JAKOB VINTHER 60

Non‐biomineralized Carapaces, Trace Fossils and the Lower Cambrian Sea‐floor Landscape: An Example from the Sirius Passet Lagerstätte of Greenland

ANTHONY J. MARTIN 61

Toward One Neoichnology: The Georgia Barrier Islands as Exemplars for Integrated Study of Modern Continental and Marine Traces and Ichnoassemblages

NICHOLAS J. MINTER, M. GABRIELA MÁNGANO AND JEAN‐BERNARD CARON 62 Skimming the Surface with Burgess Shale Arthropod Locomotion

PETE MISKELL, RICH CALLOW AND DUNCAN MCILROY 64 Paleoenvironmental Investigation of a Possible Late Cretaceous Anoxic Event from the

Rosario Formation, Baja California, Mexico

MASAKAZU NARA 65 Palaeoecology of a Pleistocene Ocean Current‐Generated Sandridge Complex: Benthic

Life Under the Kuroshio Current

MASAKAZU NARA AND LUDVIG LÖWEMARK 66 Ichnology of Neogene Wave‐Dominated Shallow Marine Settings: Examples from the

Lower Miocene Yehliu Sandstone Member in Northern Taiwan

C. NETO DE CARVALHO, JESUS SALAZAR CABRERA AND ROIGAR LÓPEZ RIVAS 67

New Findings in the “Lost World”: the Significance of Microbial Mat Related Structures and Skolithos Piperock in the Sand Flat Sequences of Roroimü Tepuy (post‐Roraima Group, Venezuela)

C. NETO DE CARVALHO, ANDREA BAUCON AND SARA CANILHO 68 Beaconites‐Taenidium‐Scoyenia Association from the Alluvial Fan Deposits of Sarzedas

Basin (Portugal)

RENATA G. NETTO , JORDI M. DE GIBERT, ZAIN BELAÚSTEGUI, H. ALLEN CURRAN AND FRANCISCO M. W. TOGNOLI 69

Ophiomorpha nodosa from Southern Atlantic Pleistocene Deposits with Comparison to Modern Callianassid Burrows of the Southernmost Coast of Brazil

AMRUTA R. PARANJAPE, KANTIMATI G. KULKARNI AND SHWETA S. GURAV 70 Implications of Gastrochaenolites‐Bearing Conglomerate at the Base of Bada Bagh

Member, Jaisalmer Formation, Rajasthan, India


vi

V.S. PARIHAR AND V. GAUR 71 Trace Fossil Assemblages in the Pokaran Sandstone of Marwar Supergroup, Pokaran

Area, District ‐ Jaisalmer, Western Rajasthan, India

V. S. PARIHAR, V. GAUR AND S.L. NAMA 72 Trace Fossils and Microbial Mat‐Induced Sedimentary Structures from the Girbhakar

Sandstone of Marwar Supergroup, Bhopalgarh Area, Jodhpur, Rajasthan, India

SATISH. J. PATEL AND A.N.REDDY 73 Ichnofossil Assemblages of a Coniacian‐Santonian Sandstone, Cauvery Basin, India

PABLO J. PAZOS, DIANA E. FERNÁNDEZ, MARCOS COMERIO AND GUILLERMO E. OTTONE

74 Ichnology of an Intertidal Palaeosurface: The Record of Tidal Water Fluctuations,

Palaeotopography, Microbial Mat Variability and Trace Fossil Distribution in the Lower Cretaceous of Patagonia, Argentina

CECILIA A. PIRRONE, LUIS A. BUATOIS AND RICHARD BROMLEY 75 Ichnotaxobases for Bone Bioerosional Structures: A Proposal

ROY PLOTNICK 76 Modeling the Movement Paleoecology of Burrowing Organisms

LUIS IGNACIO QUIROZ, KOJI SEIKE, LUIS ALBERTO BUATOIS, MARIA GABRIELA MÁNGANO AND CARLOS JARAMILLO 77 The Past as a Key to the Present: Searching for an Elusive Worm in the Tropics

ANDREW K. RINDSBERG AND ANTHONY J. MARTIN 78 Caster’s Plasters: Kenneth Caster’s Neoichnological Experiments on Limulids in the 1930s

WILLIAMS RODRIGUEZ AND LUIS A. BUATOIS 79 Ichnology, Facies Analysis and Sequence Stratigraphy in Paleoenvironmental

Characterization of Marginal Marine Reservoirs: Oficina Formation in the Orinoco Oil Belt, Venezuela

FRANCISCO J. RODRÍGUEZ‐TOVAR, ALFRED UCHMAN, XABIER ORUE‐ETXEBARRIA AND ESTÍBALIZ APELLANIZ 80 Ichnological Analysis at the Danian‐Selandian Boundary Interval in the Sopelana Section

(Basque Basin, W. Pyrenees): Approaching Palaeoenvironmental Conditions

SERGEY ROZHNOV 81 Evidence of Symbiotic Myzostomid Settlements in Early Paleozoic Echinoderms

MARIA SAVITSKAYA 82 Chondrites Brongiart, 1828 from Middle Ordovician Limestones (St.Petersburg Region,

Russia) and its Interpretation

ELIZABETH R. SCHATZ, MARIA GABRIELA MANGANO, ALEC E. AITKEN AND LUIS A. BUATOIS 83 Response of Benthos to Stress Factors in Holocene Arctic Fjord Settings: Maktak,

Coronation and North Pangnirtung Fjords, Baffin Island, Canada


vii

KOJI SEIKE, YUTA SHIINO AND YUTARO SUZUKI 84 Tubular Trace Fossil Armored with Crinoid Stem Plates from Upper Permian Shallow

Marine Deposits of Northeastern Japan

KOJI SEIKE, ROBERT G. JENKINS, HIROMI WATANABE, HIDETAKA NOMAKI AND KEI SATO 85 A New Method for Deep‐Sea Neoichnology: In‐situ Burrow Casting

HEMANTA SINGH RAJKUMAR

86 Trace Fossils and Shoreface Model of Laisong Flysch Sediments of Manipur, Indo‐Mymar

Ranges, India

HEMANTA SINGH RAJKUMAR, KUMAR SINGH KHAIDEM AND IBOTOMBI SOIBAM 87 Trace Fossils and Palaeoenvironment of Barail Flysch, Manipur, Northeast India

BIRENDRA P. SINGH AND RAVI. S. CHAUBEY 88 Sedimentation Pattern, Energy Level and Preservation of the Cruziana Ichnofacies in the

Early Cambrian Nagaur Sandstone Formation (Marwar Supergroup) Bikaner‐Nagaur Basin, Rajasthan

MICHAŁ STACHACZ AND ALFRED UCHMAN 89 Ichnological Record of the Frasnian‐Famennian Boundary interval in the Kowala Quarry

(Holy Cross Mountains, Poland)

LINA M. STOLZE AND DR. SAMUEL J. BENTLEY 90 Bioturbation in Continental Shelf and Rise Sediments of the Gulf of Maine

as Revealed by X‐ radiography

GEORGINA TARI, ARPAD DAVID AND ROZALIA FODOR 91 Feeding and Nesting Holes of Woodpeckers (Aves, Picidae) in Middle Miocene Age

Petrified Woods from North‐Hungary

YUSUKE TAKEDA AND KAZUSHIGE TANABE 92 Ventral Bite Marks in the Early Jurassic Ammonoids from the Nishinakayama Formation

in the Toyora Area, Western Japan

MICHELLE THOMS AND DUNCAN MCILROY 93 Three Dimensional Morphological Characterization of the Trace Fossil Rosselia

ALFRED UCHMAN AND JANUSZ KOTLARCZYK 94 Ichnological and Ichthyological Proxies for Palaeo‐oxygenation in the Skole Basin

(Carpathians, Poland) During the Oligocene

JOONAS VIRTASALO, MARTIN WHITEHOUSE AND AARNO KOTILAINEN 95

Sulfur and Iron Isotope Heterogeneity in the Pyrite Fillings of Holocene Worm Burrows

ANDREAS WETZEL 96

Burrows Storing an Otherwise Lost Sedimentary Record


viii

LOGAN A. WIEST, ILYA V. BUYNEVICH, DAVID E. GRANDSTAFF AND DENNIS O. TERRY, JR. 97 Ichnological Evidence for Dwarfism in Endobenthic Communities at the K‐Pg Interval in

New Jersey, USA: Paleoenvironmental Disturbance and Stratigraphic Implications

MAX WISSHAK, ALINE TRIBOLLET, STJEPKO GOLUBIC, JOACHIM JAKOBSEN AND ANDRÉ FREIWALD 98

Experimental Evaluation of Bioerosional Ichnodiversity from Intertidal to Bathyal Depths in the Azores

LI‐JUN ZHANG AND YI‐MING GONG 99 Ichnocoenosis of the Lower Devonian Pingyipu Formation in the Longmen Mountain,

Sichuan

Ichnia 2012 St. John’s, Newfoundland ‐ Schedule

1

MONDAY, AUGUST 13TH ROOM: Junior Common Room in R. Gushue Hall (2nd Floor)

19:00 Icebreaker

TUESDAY, AUGUST 14TH ROOM: EN 2006 (Engineering Building)

9:00 Welcoming addresses 9:20 SÖREN JENSEN ET AL. Testing for

Palaeogeographical Patterns in the Distribution of Cambrian Trace Fossils

9:50 ALEXANDER G. LIU, DUNCAN MCILROY AND

MARTIN D. BRASIER. Metazoan locomotion at ~565 Ma

10:10 STACEY GIBB ET AL. A Trace in Every Port:

Rusophycus carleyi Group 10:30 Coffee Break 11:10 MICHAEL GARTON AND DUNCAN MCILROY.

Feeding Trails and Mass Migrations: Large Arthropod Traces from the Early Cambrian of North‐West Scotland

11:30 NICHOLAS J. MINTER ET AL. Skimming the

Surface with Burgess Shale Arthropod Locomotion

11:50 RENATA G. NETTO ET AL. Ophiomorpha

nodosa from Southern Atlantic Pleistocene Deposits with Comparison to Modern Callianassid Burrows of the Southernmost Coast of Brazil

12:10 H. ALLEN CURRAN. Bahamian

Ophiomorpha Heaven: Pleistocene Ichnology of Harry Cay, Little Exuma

12:30 JORDI M. DE GIBERT. The Roots of Modern Shallow‐Marine Soft‐Bottom Benthic Communities: An Ichnological Approach

12:50 LUNCH ‐ provided 14:00 LUIS A. BUATOIS AND M. GABRIELA

MÁNGANO. Ichnodiversity and Ichnodisparity: Significance and Caveats

14:30 HURIYE DEMIRCAN AND DOĞAN USTA. Early

Ordovician Trace Fossils from the Amanos Mountais (NE Osmaniye, SE Anatolia)

14:50 PABLO JOAQUIN ALONSO ET AL. Postglacial Ichnofaunas of Western Gondwana: An example from the upper Carboniferous Hoyada Verde Formation of Argentina

15:10 DIANA ELIZABETH FERNÁNDEZ AND PABLO

JOSÉ PAZOS. Enhanced Preservation of Delicate Arthropod Trackways by Microbial Mat Biostabilisation in a Cretaceous Marginal‐Marine Setting from Patagonia: A Preliminary Study

15:30 Coffee Break 16:00 HEMANTA SINGH RAJKUMAR. Trace Fossils

and Shoreface Model of Laisong Flysch Sediments of Manipur, Indo‐Mymar Ranges, India

16:20 ROZALIA FODOR AND DAVID ARPAD.

Ichnology of an Early Miocene Siliciclastic Succession (Dédestapolcsány, North‐Hungary)

16:40 MAŁGORZATA BEDNARZ AND DUNCAN

MCILROY. The Palaeobiological Implications of 3D Reconstructions of Chondrites isp.

17:00 Poster Session (finishing at 18:00)

19:00 Public Lecture by Dr. Phil Manning

21st Century Dinosaurs from Hell …

Creek!

Room: EN 2006 (Engineering Building)


2

WEDNESDAY, AUGUST 15TH ROOM: EN 2006 (Engineering Building)

9:00 IAA Business Meeting 9:20 ALFRED UCHMAN AND JANUSZ KOTLARCZYK.

Ichnological and Ichthyological Proxies for Palaeo‐oxygenation in the Skole Basin (Carpathians, Poland) During the Oligocene

9:50 ANDREAS WETZEL. Burrows Storing an Otherwise Lost Sedimentary Record

10:10 MICHELLE THOMS AND DUNCAN MCILROY.

Three Dimensional Morphological Characterization of the Trace Fossil Rosselia

10:30 Coffee Break 11:10 KANTIMATI G. KULKARNI AND VIDYADHAR D.

BORKAR. Diplocraterion Torell from a Lower Cretaceous Prograding Delta Sequence, Kachchh, India

11:30 SATISH J. PATEL AND A.N.REDDY. Ichnofossil

Assemblages of a Coniacian‐Santonian Sandstone, Cauvery Basin, India

11:50 HEMANTA SINGH RAJKUMAR ET AL. Trace

Fossils and Palaeoenvironment of Barail Flysch, Manipur, Northeast India

12:10 M. GABRIELA MÁNGANO ET AL. Non‐

biomineralized Carapaces, Trace Fossils and the Lower Cambrian Sea‐floor Landscape: An Example from the Sirius Passet Lagerstätte of Greenland

12:30 MASAKAZU NARA. Palaeoecology of a

Pleistocene Ocean Current‐Generated Sandridge Complex: Benthic Life Under the Kuroshio Current

12:50 LUNCH ‐ provided 14:00 SUZANNE C. DUFOUR AND REBECCA T.

BATSTONE. The Sulphide Mining Activities of Chemosymbiotic Thyasirid Bivalves

14:30 NOELIA B. CARMONA ET AL. Ichnology of

Marine Deposits from Patagonia (Southern Argentina): the Role of the Modern Evolutionary Fauna in Neogene Infaunal Ecosystems

14:50 KENTARO IZUMI. Geochemical Analyses of

the Trace Fossil Phycosiphon incertum from Lower Jurassic Shelf Deposits: Implications for the Mineral Selection Preferences of its Tracemaker

15:10 DARIO HARAZIM ET AL. The

Biogeochemical Effect of Bioturbation: A Perspective from the Rock Record

15:30 Coffee Break 16:00 SUDIPTA DASGUPTA ET AL. Sedimentology

and Ichnology of the Palaeo‐Orinoco Shelf‐Edge Delta in the Pliocene Mayaro Formation of Trinidad

16:20 A. A. EKDALE AND JORDI M. DE GIBERT. The

Ups and Downs of Farming in a Tectonically Active Basin: Late Miocene Agrichnia in the Vera Basin of Southeastern Spain

16:40 PABLO J. PAZOS ET AL. Ichnology of an

Intertidal Palaeosurface 17:00 Poster Session 18:00 End of Day


3

THURSDAY, AUGUST 16TH

BELL ISLAND FIELD TRIP

LUNCH IS PROVIDED

8:00 Meet in the Engineering Building Main

Lobby

Important: Do not arrive late!

Bring your soccer gear with you because

the buses are driving directly to the

soccer pitch after the field trip

8:30 Buses depart for Bell Island

15:00 Approximate departure time from Bell

Island

16:00 Buses drop off participants at the soccer

pitch

The bus will return to MUN campus for

anyone who is not participating in the

soccer game

17:00 Soccer ends

19:00 Banquet

Meet at the R. Gushue Hall

Live Music Provided

23:00 End of Banquet


4

FRIDAY, AUGUST 17TH ROOM: EN 2006 (Engineering Building) 9:20 ROY PLOTNICK. Modeling the Movement

Paleoecology of Burrowing Organisms 9:50 DIRK KNAUST ET AL. Ichnology in Reservoir

Characterization of Turbidites: Lessons Learned from Outcrop Studies

10:10 DAVID ARPAD ET AL. Ichnology of Early

Miocene Shallow‐Marine Sediments in the southern Nograd Basin, North Hungary

10:30 Coffee Break 11:10 MAX WISSHAK ET AL. Experimental

Evaluation of Bioerosional Ichnodiversity from Intertidal to Bathyal Depths in the Azores

11:30 ZAIN BELAÚSTEGUI ET AL. Hard‐Substrate

Oases for Bivalve Colonization: Gastrochaenids in Dead Clypeasteroid Tests (Miocene, E Spain)

11:50 FRANCISCO J. RODRÍGUEZ‐TOVAR ET AL.

Ichnological Analysis at the Danian‐Selandian Boundary Interval in the Sopelana Section (Basque Basin, W. Pyrenees): Approaching Palaeoenvironmental Conditions

12:10 V. GAUR AND V.S. PARIHAR. New Record of

Trace Fossils from the Nagaur Sandstone of Marwar Supergroup, Dulmera Area, District‐Bikaner, Rajasthan, India

12:30 AMRUTA R. PARANJAPE ET AL. Implications

of Gastrochaenolites‐Bearing Conglomerate at the Base of Bada Bagh Member, Jaisalmer Formation, Rajasthan, India

12:50 LUNCH ‐ provided 14:00 RICHARD H.T. CALLOW ET AL. Ichnology of

Continental Slope‐channel Systems: Biological, Sedimentological and Petroleum Geological Perspectives

14:30 KORHAN AYRANCI ET AL. Biology and

Neoichnology of the Delta Front of the Asymmetrical Fraser River Delta, British Columbia, Canada

14:50 ILYA V. BUYNEVICH ET AL. Bathyal

Neoichnology with Remotely Operated Vehicles (ROVs): Fish Traces and Sediment Resuspension in the Eastern Mediterranean Sea

15:10 LUIS IGNACIO QUIROZ ET AL. The Past as a

Key to the Present: Searching for an Elusive Worm in the Tropics

15:30 Coffee Break 16:00 ANDREW K. RINDSBERG AND ANTHONY J.

MARTIN. Caster’s Plasters: Kenneth Caster’s Neoichnological Experiments on Limulids in the 1930s

16:20 MARY LEAMAN AND DUNCAN MCILROY.

Three Dimensional Morphology of

Diplocraterion

16:40 KOJI SEIKE ET AL. A New Method for Deep‐Sea Neoichnology: In‐situ Burrow Casting

17:00 Poster Session 18:00 End of day


5

SATURDAY, AUGUST 18TH ROOM: EN 2006 (Engineering Building) 9:20 LIAM HERRINGSHAW AND DUNCAN MCILROY.

The Fossil Record of Bioirrigation 9:50 JORDI M. DE GIBERT ET AL. Burrowing

Capabilities of Juvenile Thalassinideans: Paleobiological Significance of Ophiomorpha puerilis from the Pleistocene of the Bahamas and Southern Brazil

10:10 CECILIA A. PIRRONE ET AL. Ichnotaxobases

for Bone Bioerosional Structures: A Proposal

10:30 Coffee Break 11:10 VERÓNICA KRAPOVICKAS ET AL. Continental

Ichnofacies Models: The Role of Tetrapod Tracks

11:30 ANTHONY J. MARTIN. Toward One

Neoichnology: The Georgia Barrier Islands as Exemplars for Integrated Study of Modern Continental and Marine Traces and Ichnoassemblages

11:50 SHWETA S. GURAV AND KANTIMATI G. KULKARNI. Schaubcylindrichnus in the Assilina Limestone Member (Ypresian) Naredi Formation, Kachchh, India

12:10 YUSUKE TAKEDA AND KAZUSHIGE TANABE. Ventral Bite Marks in the Early Jurassic Ammonoids from the Nishinakayama Formation in the Toyora Area, Western Japan

12:30 HENDRIK KLEIN AND SPENCER G. LUCAS. The Late Triassic Phytosaur Ichnotaxon Apatopus lineatus (Bock, 1952) and Other Footprints That Demonstrate Parallel Evolution of the Semi‐aquatic Lifestyle in Archosaurs

12:50 LUNCH ‐ provided 14:00 KAREN CHIN. Burrow/Coprolite

Associations: Anomalous or Expected? 14:30 ILYA V. BUYNEVICH ET AL. Occurrence and

Preservation Potential of Modern Vertebrate Traces in Contrasting Geological Settings Along the Northwestern Black Sea Coast, Ukraine

14:50 DANIEL HEMBREE ET AL. Improving the

Interpretation of Continental Ichnofossils Through Experimental Neoichnology of Modern Soil Animals

15:10 DESMOND WILLIAM KRUMMECK. Large

Burrows and Paleoenvironmental Reconstructions of the Early Triassic Katberg Formation, South Eastern Main Karoo Basin, South Africa

15:30 ILYA V. BUYNEVICH ET AL. Georadar Signatures of Vertebrate Burrows Across a Gypsum Dunefield: White Sands, New Mexico, USA

16:00 Poster Session 16:20 Poster Session 16:40 Poster Session 17:00 Poster Session 18:00 End of day


6

SUNDAY, AUGUST 19TH to 22ND WESTERN NEWFOUNDLAND POST‐CONFERENCE FIELD TRIP Please see the field guide for a detailed schedule

19TH Depart from St. John’s, NL (8:00) 22ND Conclude the field trip in Deer Lake, NL

SUNDAY, AUGUST 19TH to 21ST ICHNOLOGY OF THE PRECAMBRIAN‐CAMBRIAN POST‐CONFERENCE FIELD TRIP

Please see the field guide for a detailed schedule

19TH Depart from St. John’s, NL (9:00) 21ST Conclude the field trip in St. John’s, NL

THURSDAY, AUGUST 23RD CORE VIEWING WORKSHOP

CORE FROM REDMANS FORMATION, BELL ISLAND, NEWFOUNDLAND

12:00 Meet outside the Main Office of the

Earth Science Building ER 4063 (4th Floor) LUNCH – provided

13:00 Core Viewing Workshop Begins Earth Science Building

Room ER 6044 (6th Floor) 17:00 End of Core Viewing Workshop

FRIDAY, AUGUST 24TH CORE VIEWING WORKSHOP

CORES FROM BEN NEVIS AND HIBERNIA FORMATIONS, OFFSHORE NEWFOUNDLAND

8:30 Meet in the Main Lobby of the Earth

Science Building (3rd Floor) 8:45 Depart for CNLOPB Building Transportation is provided 9:00 Core Viewing Workshop Begins at the CNLOPB Building 30 Duffy Place, St. John’s 12:00 LUNCH – provided 16:00 End of Core Viewing Workshop Return to MUN campus Transportation is provided

Ichnia 2012 St. John’s, Newfoundland ‐ Abstracts

7

PABLO JOAQUIN ALONSO1, LUIS ALBERTO BUATOIS2 AND CARLOS OSCAR LIMARINO1

Postglacial Ichnofaunas of Western Gondwana: An example from the upper Carboniferous

Hoyada Verde Formation of Argentina

1Universidad de Buenos Aires, Departamento de Ciencias Geológicas, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina 2University of Saskatchewan, Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan, Canada E‐mail: [email protected] Type of Presentation: Talk The Upper Carboniferous Hoyada Verde Formation of the Calingasta‐Uspallata Basin of Argentina provides an opportunity to document postglacial ichnofaunas. Lingulichnus verticalis, Lockeia isp., Palaeophycus isp., Protovirgularia isp., Psammichnites plummeri, Psammichnites implexus, Ptychoplasma vagans, Treptichnus bifurcus, scarce arthropod trackways and a short bilobate structure are present in these progradational deposits that occur above the maximum flooding interval that marks the culmination of the postglacial transgression. This ichnofauna is characterized by the dominance of horizontal trace fossils and subordinate presence of vertical and inclined structures, which represent different ethological categories. It is dominated by simple and small forms restricted to bedding planes, whereas shallow vertical structures are scarce and only locally present. The Hoyada Verde ichnofauna shows affinities with the Cruziana Ichnofacies, although the low to moderate ichnodiversity, relatively small size, sporadic distribution of trace fossils with localized high abundance, impoverishment of suspension‐feeding trophic types, and very low bioturbation intensities suggest a stressed expression, which is consistent with a deltaic context. In addition, postglacial biotas may have been influenced to some degree by the salinity gradient triggered by freshwater release near to melting ice masses stored in adjacent highlands. Distinction between normal‐marine and brackish‐water settings in glacially influenced environments using trace fossils may not be as straightforward as in non‐glacial settings.


8

DAVID ARPAD1, MAGDOLNA HORVATH1 AND ROZALIA FODOR2

Ichnology of Early Miocene Shallow‐Marine Sediments in the southern Nograd Basin, North

Hungary 1Karoly Eszterhazy College, Leanyka u. 6., H‐3300 Eger, Hungary 2Matra Museum, Kossuth u. 40, H‐3200 Gyöngyös, Hungary E‐mail: [email protected] Type of Presentation: Talk Trace fossils of three Early Miocene age shallow‐marine siliciclastic localities located in the southern part of the Nograd Basin, North Hungary have been examined. The formations of the examined localities belong to the Garab Schlier Formation. Limonitic sandstone layers are characteristic of the first locality. There are numerous gravel layers. Clay‐rich clasts also occur in great quantity. This outcrop is the richest in ichnofossils: Ophiomorpha nodosa, Planolites montanus, Rosselia socialis, Rosselia isp., Thalassinoides suevicus and Thalassinoides isp. Trace fossils are absent beneath the gravel layer. Stratigraphically above it are beds with P. montanus, which is the dominant ichnotaxon of the locality. Its abundance decreases going upward. In the lower part O. nodosa, Rosselia isp. and Thalassinoides isp. occur sporadically. The upper boundary of this diverse ichnoassemblage is the above‐mentioned sandstone bed. Thalassinoides suevicus is the dominant ichnospecies of the bed. Above the sandstone bed P. montanus occurs and becomes significant again. Above this P. montanus, R. socialis appears. It is the stratigraphically highest ichnoassemblage of the pit. The second locality mainly consists of homogenous limonitic sand or friable sandstone. The only ichnospecies recorded from the second outcrop is the P. montanus. The 3rd outcrop is an abandoned sandpit. Alternation of fine‐grained sand and clay can be observed. Clay layers and coarse grained gravels also occur. The trace fossils of the exposure are P. montanus, Ophiomorpha isp., T. suevicus and Rosselia isp., with P. montanus the dominant ichnotaxon. The trace fossils belong to both the Skolithos and Cruziana ichnofacies. The assemblage with O. nodosa, Ophiomorpha isp., P. montanus, T. suevicus, Thalassinoides isp. is taken to infer deposition in the distal part of the lower shoreface, while the occurrence of R. socialis marks the top of the lower shoreface. The ichnoassemblages represent an upward‐shallowing marine depositional environment.


9

KORHAN AYRANCI1, JAMES A. MACEACHERN1 AND SHAHIN E. DASHTGARD1

Biology and Neoichnology of the Delta Front of the Asymmetrical Fraser River Delta, British

Columbia, Canada

1Simon Fraser University, Earth Sciences Department, Simon Fraser University, 8888 University dr. Burnaby, BC, Canada. V5A 1S6 E‐mail: [email protected] Type of Presentation: Talk The Fraser River delta exhibits sedimentological, biological and ichnological asymmetry of the delta front. The up‐drift portion (south of the Main Channel) of the delta front comprises heterolithic sand‐mud interbeds, displaying limited infaunal diversities (H` 0.9‐1.5) and low bioturbation intensities (BI 0‐3). The dominant trace‐makers are polychaetes and bivalves, producing a neoichnological assemblage characterized by sporadically distributed simple vertical and horizontal burrows (e.g. Planolites, Skolithos, Palaeophycus and Cylindrichnus), attributable to the Skolithos Ichnofacies. The downdrift portion of the delta front (north of the Main Channel) comprises muddy bedsets that are intensely bioturbated (BI 3‐6) and display a diverse community (H` 1.4‐2.3) of infaunal polychaetes, bivalves, sea cucumbers and sea urchins. Down‐drift delta front sediments contain robust, fully marine suites of traces (e.g. Rosselia, Asterosoma, Gyrolithes, Teichichnus, Scolicia, Artichnus, Arenicolites, Polykladichnus, Thalassinoides and Phycosiphon), attributable to the Cruziana Ichnofacies. The asymmetrical character of the Fraser River delta is sedimentologically similar, but ichnologically and biologically dissimilar to its wave‐dominated counterparts. Dominant northward flow of tidal currents controls sediment dispersion from the Main Channel, such that the up‐drift delta front (to 150 m water depth) is dominated by sand, whereas the down‐drift delta front is mud‐dominated. Biological and ichnological trends show a trend opposite to that observed in wave‐dominated asymmetrical deltas, in that the biology, trace diversity and infaunal density are higher on the down‐drift side of the delta front. The lower salinities, higher water turbidity, increased depositional energy and increased sedimentation rates on asymmetrical mixed river‐ and wave‐influenced deltas do not have the same impact on infauna below storm‐wave base compared with tidally‐influenced counterparts.


10

KORHAN AYRANCI1 AND SHAHIN E. DASHTGARD1

Infaunal Holothurians of the Fraser River Delta: Their Traces and Distributions

1Simon Fraser University, Earth Sciences Department, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada. V5A 1S6 E‐mail: [email protected] Type of Presentation: Poster Holothurians (sea cucumbers) constitute one of the largest and most abundant groups of infauna inhabiting the delta front and prodelta of the Fraser River delta, Canada. Four hundred and seventeen individuals representing three orders of Class Holothuroidea were collected from 64 stations at water depths ranging from 30 to 330 m. All animals were burrowing, suspension‐ or deposit‐feeders. The spatial distributions of holothurians are asymmetrical with respect to the main river distributary and the dominant tidal flow direction (northward). Consequently, the neoichnological signature of the delta front differs from upstream (south) to downstream (north) side of the main distributary channel. This asymmetry is mainly controlled by grain‐size related stresses, which in turn reflect tidal controls on sedimentation. Sandy substrates dominate on the upstream side of the delta front and the holothurian population is low. The downstream side of the delta front is dominated by muddy substrates that are highly colonized by holothurians. The prodelta on both the upstream and downstream sides of the delta is mud‐dominated and is highly colonized by holothurians. In addition to the dominant grain‐size control, there are localized stresses that influence holothurian distribution. Anthropogenic factors or river‐derived suspended sediment concentrations clearly affect sea cucumber colonization patterns. Through a comparison of traces observed in sediment cores, mapped holothurian distributions and published studies on the ethology of sea cucumbers, several subsurface and surface traces are attributed to the holothurians. Subsurface traces include Asterosoma‐, Artichnus‐ and Thalassinoides‐like traces, as well as U‐shaped biodeformation structures (previously attributed to Diplocraterion). On the sediment surface, biotopographic structures such as mounds and funnel‐shaped depressions are attributed to sea cucumber activity.


11

MAŁGORZATA BEDNARZ1 AND DUNCAN MCILROY1

The Palaeobiological Implications of 3D Reconstructions of Chondrites isp.

1MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Talk Chondrites is a distinctive trace fossil described from fine‐grained rocks in a wide range of marine depositional settings. Previous reconstructions of the geometry of Chondrites resemble root‐like structures, starting with a vertical master shaft leading down from the top of the bed to a downward branching system. Acceptation of the existence of the vertically directed master shaft, and a lack of consideration of any deviation from the downward direction and inclination of burrow branches has resulted in conservative models of Chondrites system geometry. We present new deterministic reconstructions of several forms of Chondrites from two different geological intervals and locations. New characteristics of the burrows are herein illustrated deterministically in three dimensions. Key features observed in the reconstructed burrow systems include upward inclination of the whole burrow system or its branches, and a compound master shaft that is composed of several bundled and horizontally directed tunnels. The geometry of the reconstructed burrows of Chondrites provides a basis for revising pre‐existing palaeobiological models, particularly those that assume a passive tunnel infill, or those interpreting chemosymbiotic organisms as the trace‐makers. As a consequence, the reconstructions require new discussions on the identification of Chondrites trace‐maker/s, and the means by which sediments were transported into the burrow systems.


12

ZAIN BELAÚSTEGUI1, JORDI M. DE GIBERT1, JAMES H. NEBELSICK

2, ROSA DOMÈNECH1

JORDI MARTINELL1, IMRAN A. RAHMAN

3 AND SAMUEL ZAMORA

4

Hard‐Substrate Oases for Bivalve Colonization: Gastrochaenids in Dead Clypeasteroid Tests (Miocene, E Spain)

1Departament d’Estratigrafía, Paleontologia i Geociències Marines, Universitat de Barcelona, Martí i Franquès s/n, 08028 Barcelona, Spain 2Institut für Geowissenschaften, Universität Tübingen, Sigwartstraße 10, D‐72076 Tübingen, Germany 3School of Geography, Earth & Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom 4Department of Palaeontology, The Natural History Museum, London, United Kingdom E‐mail: [email protected] Type of Presentation: Talk Intense endoskeletozoan colonization of Clypeaster tests is a common feature of shallow‐water, bioclastic carbonates from the Middle Miocene of Tarragona (NE Spain). Preserved evidence consists of borings and associated carbonate secretions (crypts). Two different modes of occurrence have been recognized: ‘intrastereom clavate borings’ are restricted to the echinoid stereom, while ‘semi‐endoskeletal dwellings’ cross through the stereom and extend as secreted crypts into the sediment infilling the test lumen. The general morphology of the dwellings (Gastrochaenolites dijugus) and the external knobby character of the lining allow identifying the tracemakers as gastrochaenid bivalves. The high abundance and density of these structures and their location within the tests rule out a syn‐vivo relationship between the host and the colonizers and prove that colonization took place on dead skeletons lying on the sandy, bioclastic, unconsolidated seafloor. Intrinsic features of Clypeaster, such as the endurance of their skeletons and their pronounced bell‐shaped morphology, made these echinoids the most suitable substrates for hard‐bottom colonizers in such soft‐substrate, high energy environments. This kind of infestation is not uncommon in other Neogene and Quaternary localities, recording the long‐term usage of dead echinoid skeletons by gastrochaenid bivalves. New material from terrigenous Miocene deposits of Valencia (E Spain) with identical features has been imaged using X‐ray micro‐tomography and reconstructed as a three‐dimensional ‘virtual fossil’ to reveal more detailed aspects of the distribution of the dwellings and to aid in the identification of the tracemaker.


13

CHRIS BOYD1 AND DUNCAN MCILROY1

Three Dimensional Morphological Modelling of Parathaentzschelinia isp.

1MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Poster Although serial grinding is far from a novel technique, having been used for the past 100, its use has been limited. The computer‐aided tomographic reconstruction techniques were first applied to body fossils, and have subsequently been modified for use with trace fossil/ichnofabric data. The integration of this three dimensional morphological data with reservoir quality assessment is fundamental since bioturbation plays an important part in many petroleum reservoirs. The techniques of progressively grinding and photographing through trace fossils have previously been used to study in detail the pelletal morphology of Ophiomorpha irregulaire. The level of detail achieved using this technique is unmatched by any of the more traditional methods, including CT scanning, MRI or X rays, having the advantage that lithology, not just bulk rock properties, can be directly studied. Samples of Parathaentzschelinia isp. were collected in October 2011 from Cullernose Point, Northumberland, UK (55.458397N, 1.592664W) in the Stainmore Formation (Carboniferous, Namurian). They have been serially ground and photographed, and subsequently modelled to examine the detailed morphological characteristics of the burrow. Parathaentzschelinia isp. was first described in 1971, and has since had a very limited presence in literature. We will expand the understanding of this complex trace fossil.


14

LUIS A. BUATOIS1 AND M. GABRIELA MÁNGANO1

Ichnodiversity and Ichnodisparity:

Significance and Caveats 1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan, Canada E‐mail: [email protected] Type of Presentation: Talk Ichnodiversity has been used as a proxy for environmental stress and stability in facies interpretations and to reconstruct evolutionary radiations and colonization histories in evolutionary paleoecology. The three components of global diversity may be adapted for ichnology. Alpha ichnodiversity is used for paleoenvironmental characterization, being assessed for individual facies. Beta ichnodiversity is commonly overlooked, although it may provide information about degree of similarity between ichnofaunas formed along environmental gradients. Gamma ichnodiversity may provide clues to detect ichnofossil provincialism. The concept of disparity, first introduced by S. J. Gould, may also prove to be significant in ichnological studies. Whereas ichnodiversity refers to ichnotaxonomic richness, ichnodisparity provides a measure of the variability of morphological plans and fabricational designs in biogenic structures. Changes in global ichnodiversity do not necessarily parallel changes in ichnodisparity. For example, while the Cambrian explosion involved a dramatic increase in both, the Ordovician radiation essentially reflects an increase in the former. Ichnodiversity and ichnodisparity should be used with caution because they are both affected by taphonomic processes. High diversity of superficial to shallow‐tier trace fossils may result from enhanced preservation due to a poorly developed mixed layer, rather than a true reflection of ecosystem performance, as shown by underexploited infaunal ecospace after biotic crises (e.g. end‐Permian mass extinction).


15

ILYA V. BUYNEVICH1, R. TSADOK2, M. RUBIN 2, J. BENNER 3 J.A. AUSTIN, JR. 4, S.T. HASIOTIS

5, D.F. COLEMAN 6,

R.D. BALLARD6, BEN Z. AVRHAM2 AND Y. MAKOVSKY

2

Bathyal Neoichnology with Remotely Operated Vehicles (ROVs): Fish Traces and Sediment Resuspension in the Eastern Mediterranean Sea

1Temple University Department of Earth & Environmental Science 1901 N 13th Street Philadelphia, PA 19122, USA 2University of Haifa Leon H. Charney School of Marine Sciences Mt. Carmel, 31905,Israel 3Tufts University Department of Geology, Medford, MA 02155, USA 4University of Texas, Institute for Geophysics, John A. and Katherine G. Jackson School of Geosciences Austin, TX 78758‐4445, USA 5University of Kansas Department of Geology 1475 Jayhawk Blvd. Lawrence, KS 66045‐7613, USA 6University of Rhode Island, Graduate School of Oceanography, Narragansett, Rhode Island 02882, USA E‐mail: [email protected] Type of Presentation: Talk In contrast to shallow‐water neoichnology, research on biogenic structures made by large deep‐water fish is logistically challenging due to unique physical and biological requirements to observe their formation. This study focuses on real‐time observations of near‐bottom activity by benthic and bentho‐pelagic fish by remotely operated vehicles (ROVs). Fish behaviour and resulting traces were documented at four sites along the bathyal region (500‐2,000 m) offshore Israel, one of the most biologically impoverished regions of the world's oceans. Numerous medium‐scale (5‐50 cm) biogenic structures are clearly visible from ROV Argus at 10‐20 m above the seafloor. At close range, high‐resolution video of the main tethered ROV Hercules revealed a suite of piscine traces made in soft or partially compacted carbonate ooze. These include grooves of varying width, circular and semicircular depressions, swimming and lateral sliding trails, as well as traces reflecting sheltering, nesting and camouflaging and ambush behaviour by skates, scorpionfish, eels and blennoid species. Several tracemakers were observed in the process of producing biogenic structures or utilizing depressions and burrows generated by other fish and invertebrates. A number of features resemble modern and ancient Undichna and Piscichnus traces, including escape into sediment and a full impression of a longnosed skate. ROVs also captured behaviour leading to sediment resuspension, which is attributed to feeding, rapid collision with the seafloor and contact by four sets of fins. The documented groove‐and‐rim structures range from 0.1‐0.6 m in length, in contrast to >1.5 m‐long excavations, which earlier scientists attribute to deep‐diving cetaceans in the vicinity of northern Mediterranean underwater volcanoes. Neoichnological ROV observations will continue to shed light on benthic species abundance and diversity, offering modern‐day analogs for biogenic structures in deep‐water sedimentary sequences.


16

ILYA V. BUYNEVICH1, SERGEY KADURIN2, IGOR LOSEV2, DMITRY KOLESNIK2, IGOR DARCHENKO2 AND EVGENY

LARCHENKOV2

Occurrence and Preservation Potential of Modern Vertebrate Traces in Contrasting Geological

Settings Along the Northwestern Black Sea Coast, Ukraine

1Temple University, Earth and Environmental Science, 1901 N 13th Street, Philadelphia, PA 19122 2Odessa National University, Physical and Marine Geology, 2 Shampansky Per., Odessa 65058, Ukraine E‐mail: [email protected] Type of Presentation: Talk Black Sea lowlands have been inhabited since antiquity, with coastal and fluvial sediments serving as potential archives of wild and domesticated animal ichnites spanning more than 2,000 years. A diverse assemblage of mammalian and avian traces occurs in a suite of depositional settings at five sites along the coast of the Odessa region, Ukraine. Tridactyl trackways made by several wading bird species range from 3 to 12 in length and occur on algal mudflat surfaces of barrier‐fronted embayments (limans). In hypersaline limans, buried track‐bearing surfaces are converted to 20‐30cm‐thick hardgrounds. Avian traces are occasionally associated with canid tracks and hoofprints of domestic ungulates (cattle and horses). Large fox burrows are excavated in prograded beach‐ridge complexes, especially in raised vegetated sections capped by aeolian deposits. Subsurface extensions of empty burrows and dens can be identified in high‐frequency georadar images due to dielectric contrast with the enclosing medium‐to‐coarse sands. Along the upper beachface and upper berm regions, large tracks are accentuated by heavy‐mineral concentrations of swash and aeolian genesis, respectively. Given a net long‐term shoreline accretion, these lithological anomalies will enhance the potential for trace recognition, both in trenches and by geomagnetic methods. With rising sea levels, shoreline retrogradation and breaching will result in destruction of shallow biogenic structures within barrier lithosomes, while preserving back‐barrier tracks beneath wash‐over deposits. In contrast, coastal progradation and aggradation ensures preservation of tracks and burrows in beach and dune deposits. Even though the slowly rising water table will impede both recognition and recovery of biogenic structures by traditional methods, the potential for their identification and mapping by georadar will be improved due to increased signal resolution (~2 cm at 800 MHz) in saturated sediments.


17

ILYA V. BUYNEVICH1, ANDREW BENTLEY1, DAVID BUSTOS2, DOUGLAS JEROLMACK3 AND GARY KOCUREK4

Georadar Signatures of Vertebrate Burrows Across a Gypsum Dunefield:

White Sands, New Mexico, USA

1Temple University, Earth and Environmental Science, 1901 N 13th Street, Philadelphia, PA 19122, USA 2National Park Service, White Sands National Monument, PO Box 1086, Holloman AFB, NM 88330, USA 3University of Pennsylvania, Earth and Environmental Science Philadelphia, PA 19104, USA 4University of Texas – Austin, Jackson School of Geosciences, Austin, TX 78758‐4445, USA E‐mail: [email protected] Type of Presentation: Talk In the world’s largest gypsum dunefield, at White Sands National Monument, modern vertebrate burrows occur in a variety of sub‐environments, which include (in a downwind direction): vegetation‐anchored coppice dunes or bare surfaces adjacent to barchans, sparsely vegetated transitional interdunes, densely vegetated blowout sections of parabolic dunes and raised margins of ephemeral playa lakes. The primary semi‐fossorial producers of 7‐20 cm‐wide sub‐horizontal to steeply inclined excavations are desert kit fox (Vulpes macrotis), banner‐tail kangaroo rat (Dipodomys spectabilis) and burrowing owl (Athene cunicularia). In the interdunes, the excavation depth is limited by a relatively shallow (~1 m) water table. To assess, in a non‐invasive manner, the subsurface extent and geophysical signal scattering effect of active burrows, continuous high‐resolution images were obtained using 500 and 800 MHz georadar (GPR) antennas. In radargrams, burrows appear as hyperbolic (point‐source) diffractions, with apparent diameters ranging from 14‐30 cm (due to actual size increase or any deviation from an attitude normal to the transmitted GPR trace). Occasionally, the sub‐decimeter resolution allows differentiation between the tunnel roof and the floor, with the latter represented by a characteristic “pull‐up” as the electromagnetic signal passes through the air‐filled void. Most shafts and tunnels truncate major bounding discontinuities (interdune migration and reactivation surfaces), although the potential for recognizing and mapping the infilled and buried voids is limited by low dielectric contrast within lithologically homogeneous aeolian deposits. However, localized changes in bedding geometry and chemical processes that accentuate burrow walls may compensate for this limitation. This study demonstrates the use of geophysical methods for identifying bioturbation structures and characterizing ichnocoenoses formed in ancient evaporite basins and other wet aeolian systems.


18

RICHARD H.T. CALLOW1, DUNCAN MCILROY2, BEN KNELLER1 AND MASON DYKSTRA3

Ichnology of Continental Slope‐channel Systems: Biological, Sedimentological and Petroleum

Geological Perspectives

1Department of Geology and Petroleum Geology, University of Aberdeen, Meston Building,

King’s College, Aberdeen, AB24 3UE, UK 2Department of Earth Sciences, Memorial University of Newfoundland, St John’s, NL A1B 3X5,

Canada 3Department of Geology and Geological Engineering, Colorado School of Mines, Golden, CO

80401, USA

E‐mail: [email protected]

Type of presentation: Talk

Sediments of the continental slope are commonly highly bioturbated by endo‐ and epibenthic

organisms, especially in and around submarine canyons and channels, which are commonly

centres of elevated biomass and biodiversity. Submarine channels act as conduits for turbidity

currents and represent important sites of sediment deposition. The sedimentary rocks

deposited in these environments are globally important hydrocarbon reservoirs. The study of

bioturbation (ichnology) can be a powerful and valuable tool in facies analysis and reservoir

characterization of hydrocarbon systems, but has yet to be applied routinely to the analysis of

deep marine sediments from slope environments. We review the architecture, depositional

environments and the likely physical and chemical conditions across slope‐channel systems. By

integrating current knowledge of sedimentology, biology and ichnology of slope environments

it is possible to provide a first order summary of the inter‐relationships between ichnology and

depositional environments on the continental slope. Key controls on benthic assemblages in

slope‐channel systems are discussed in order to develop a predictive framework for likely

stresses on benthic ecosystems, and concomitantly trace fossil distributions.

We demonstrate how ichnology can be used as a tool to interpret depositional environments in

turbidite‐influenced submarine channel systems. This discussion demonstrates that ichnology is

an important resource that has the potential to provide additional palaeoenvironmental

insights when coupled with sedimentological datasets. The integration of ichnological data

within detailed, high‐resolution sedimentological and facies architectural frameworks has the

potential to improve our understanding of deep marine benthic ecosystems through geological


19

time, and to further the use of ichnology in studying bioturbated cores from slope and

submarine channel reservoirs.


20

NOELIA CARMONA1, CONSTANZA BOURNOD2, JUAN JOSÉ PONCE1, DIANA CUADRADO2

AND ANDREAS WETZEL3

Microbial Mats and Their Role in the Preservation of Vertebrate Footprints: Modern Tracks

and Their Fossil Counterparts 1CONICET‐UNRN, Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Isidro Lobo y Belgrano, (8332) Roca, Río Negro, Argentina 2IADO, Instituto Argentino de Oceanografía (IADO) ‐ CONICET ‐CC 804 B8000FWB. Bahía Blanca, Argentina 3Universität Basel, Geologisch‐Paläontologisches Institut, Universität Basel, Bernoullistrasse 32, CH‐4056 Basel, Switzerland E‐mail: [email protected] Type of Presentation: Poster Studies of recent environments with microbial mats increased considerably during the last years, not only because their unique sedimentological and ecological characteristics, but also because they provide important implications for the understanding of fossil environments and palaeocommunities. The role of microbial mats in the preservation of bird tracks was studied in detail in lower‐supratidal flats of the Bahia Blanca estuary, Argentina. For several months a number of selected footprints were photographed to record the morphological modifications they experienced with time. The footprints showed resistance to tide‐ and wind‐erosion and also to heavy rains and storms. The strongly lowered erodability is clearly associated to the presence of the microbial mats, which biostabilize the sediment. In addition, microscopic analysis of the tidal‐flat sediment revealed the presence of zeolites and calcite being suggestive of early cementation, which very likely enhanced the preservation potential of the footprints. Along with these observations, the study of fossil counterparts analyzed in the Rio Negro Formation (Lower Miocene‐Pliocene), allowed the identification of various microbially induced sedimentary structures in tidal‐flat facies. These Neogene deposits, in fact, represent classical localities for the study of vertebrate trace fossils in Argentina, while containing diverse, excellently preserved tracks of mammals and different birds. Thus, considering the data from the modern setting and the information from sedimentological studies in the rock record, it becomes evident that the presence of microbial mats played an important role in the preservation of the footprints mainly in three ways. First, the microbially stabilized sand behaved plastically, preserving the imprints better than pure cohesionless sand. Second, microbial mat decay induced early cementation processes, stimulating mineral precipitation, as it occurs in modern settings. And third, the near‐surface cementation and the reducing conditions below the microbial mats also precluded the colonization by large endofauna, preventing therefore the obliteration of the vertebrate footprints.


21

NOELIA B. CARMONA1, LUIS A. BUATOIS2, M. GABRIELA MÁNGANO

2, RICHARD G. BROMLEY3, JUAN JOSÉ PONCE1,

E. BELLOSI4 Ichnology of Marine Deposits from Patagonia (Southern Argentina): the Role of the Modern

Evolutionary Fauna in Neogene Infaunal Ecosystems 1CONICET‐UNRN, Instituto de Investigación en Paleobiología y Geología, Universidad Nacional de Río Negro, Isidro Lobo y Belgrano, (8332) Roca, Río Negro, Argentina 2Department of Geological Sciences. University of Saskatchewan. 114 Science Place. Saskatoon. SK S7N 5E2, Canada 3Department of Geography and Geology. University of Copenhagen. Øster Voldgade 10. 1350 Copenhagen K. Denmark 4CONICET‐Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Av. Angel Gallardo 470, C1405DJR, Buenos Aires, Argentina E‐mail: [email protected] Type of Presentation: Talk

Neogene deposits from Patagonia are characterized by extremely diverse ichnofaunas, including a great variety of feeding (e.g., Asterosoma, Helicodromites, Phycosiphon, Rosselia, Teichichnus), grazing (e.g., Nereites, Scolicia, Taenidium) and dwelling (e.g., Balanoglossites,

Gastrochaenolites, Gyrolithes, Ophiomorpha, Spongeliomorpha, Schaubcylindrichnus, Thalassinoides) structures. Subordinately, locomotion (e.g., Protovirgularia) and

equilibrium/escape structures (e.g., Scalichnus) occur. Trace fossils in open marine deposits are abundant and diverse, with extremely complex tiering structures, and most commonly characterized by the presence of the archetypal Cruziana ichnofacies. On the contrary, restricted, commonly tide‐influenced, brackish environments show low to moderate ichnodiversity, monospecific associations, generally small sizes, and the presence of an

impoverished Cruziana‐Skolithos ichnofacies. Irregular echinoid structures are abundant mainly in open‐marine environments while those produced by bivalves and crustaceans dominate the open and brackish‐marine ichnofaunas, reflecting the peak of the Modern evolutionary Fauna. Ichnofaunas of modern aspect seem to have been well established in shallow‐marine, open environments since the Mesozoic, and this is particularly well exemplified in the Neogene ecosystems from Patagonia, where finely tuned climax communities display vertical niche

partitioning and a remarkable use of the infaunal ecospace. These observations agree with the trends exhibited by the body fossil record, which show that for the middle latitude successions for the Late Cenozoic, marine paleocommunities show a greater representation of infaunal organisms, especially of deep‐burrowers. In addition, local influence of nutrient‐rich waters

brought to the surface during upwelling along the Patagonian coast may have also contributed to the increasing complexity seen in these Neogene infaunal ecosystems.


22

KAREN CHIN1

Burrow/Coprolite Associations: Anomalous or Expected?

1University of Colorado Boulder, 265 UCB, Boulder, CO 80309, USA E‐mail: [email protected] Type of Presentation: Talk Fossil burrows and coprolites (including fecal pellets) have distinctly different taphonomic features and present different research challenges. Whereas many fossil burrows have well‐defined and recurring morphologies, coprolites are often less recognizable and can be highly variable. As such these ichnofossils are usually investigated in separate studies. Yet there are numerous examples of burrow/coprolite associations and it is likely that they co‐occur more often than might be expected. Such relationships reflect how burrowing and resource utilization are integrated. Animals generally burrow near their food sources and in turn, also tend to defecate in the vicinity of feeding areas—near domiciles or rich food sources. Two basic burrow/coprolite associations can be defined: coprophagous‐burrower and pellet‐producing‐burrower associations. In coprophagous‐burrower associations, small dung‐eating organisms feed and burrow in proportionately larger fecal masses. In most cases the identity of the defecator and burrower are unknown, though inferences about the types of participants can be made. In pellet‐producing‐burrower associations, both burrows and fecal pellets are probably produced by the same animals. Fecal pellets may be distributed randomly within or around burrows, or they may be found consistently in specific areas, such as at the openings of permanent burrows. There are marine and terrestrial examples of both types of fossil burrow/coprolite associations, involving such disparate inferred tracemakers as dinosaurs, dung beetles, earthworms, sharks and ghost shrimp. Although many coprolites lack a consistent and diagnostic morphology, their association with burrows can contribute new information about behaviour, diet and food webs. Scarce and sporadic versus extensive burrowing within large coprolites may reflect solitary foraging rather than aggregated populations. Phosphatic versus clay‐rich fecal pellet compositions shed light on feeding strategies. The co‐occurrence of burrows with coprolites may also offer more diagnostic features with which to recognize ichnotaxa or identify tracemakers. An increased awareness of burrow/coprolite associations should reveal additional recurring associations that enhance our understanding of paleobiological context.


23

H. ALLEN CURRAN1

Bahamian Ophiomorpha Heaven: Pleistocene Ichnology of Harry Cay, Little Exuma

1Department of Geosciences, Smith College, 44 College Lane, Northampton, Massachusetts 01063, USA E‐mail: [email protected] Type of Presentation: Talk A road metal quarry at Harry Cay, southwest coast of Little Exuma Island, exposes an excellent Upper Pleistocene (MIS 5e) sequence of shallow marine skeletal and peloidal grainstones. These strata contain an ichnocoenosis dominated by large, well‐formed Ophiomorpha, commonly with complex architecture, and large specimens of Conichnus conicus. Also present but less abundant are Skolithos linearis in a range of diameters and Planolites. These grainstones also are characterized by trough and tabular cross‐bedding and are interpreted as representing deposition in a shallow subtidal environment under shoaling conditions influenced by nearshore and/or tidal currents. Ophiomorpha is attributed to the burrowing activity of callianassid shrimp, and segments of robust shafts and tunnels up to 5 cm in outside diameter and parts of mazes with enlarged, rounded and gently downward directed termini are abundant in the broken paleosol that caps low areas of Harry Cay. These highly distinctive termini have thick walls and are well pelleted on the exterior. C. conicus has been attributed to the escape‐burrowing activity of sea anemones under conditions of rapid sedimentation; however, a mechanical origin should not be ruled out. Meandering Planolites specimens probably represent the activity of polychaetes, as do the forms of S. linearis. Recently, specimens of Ophiomorpha puerilis were discovered at Harry Cay and they are interpreted as representing the initial burrows of juvenile callianassids. This characteristic ichnocoenosis of Harry Cay also occurs at several other sites in the Bahamas, in parts of the Miami Limestone of south Florida, the Ironshore Formation of the Cayman Islands and likely elsewhere in similar tropical carbonate grainstone deposits. Future research goals include achieving better understanding of the architecture of large, complex Ophiomorpha systems, the relationship of O. puerilis to them and the mechanism of formation of C. conicus.


24

SUDIPTA DASGUPTA1, LUIS A. BUATOIS1 AND MARIA GABRIELA MÁNGANO1

Sedimentology and Ichnology of the Palaeo‐Orinoco Shelf‐Edge Delta in the Pliocene Mayaro

Formation of Trinidad

1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan, Canada, S7N 5E2 E‐mail: [email protected] Type of Presentation: Talk The Pliocene Mayaro Formation of Trinidad shows a south to north facies‐asymmetry of the shelf‐edge delta succession developed by the palaeo‐Orinoco river. Fluvial influence towards the south is evidenced in the delta front sand‐bodies by the presence of outsized gutter‐casts, phytodetrital pulses, and collapsed banks of channels, all indicating proximity towards distributary channel complexes on a high gradient shelf‐edge. These sandy lithosomes in the south are almost devoid of ichnofossils and the associated heterolithic sediments are also rarely bioturbated with a very low diversity suite of Skolithos, Planolites, Teichichnus, Asterosoma, Siphonichnus and escape traces. Trace fossils are significantly reduced in size and more than two ichnotaxa rarely occur together. The background wave dominance gradually increases towards the northern outcrops, where the delta front sand‐bodies are more tabular and are characterized by an Ophiomorpha nodosa suite. The heterolithic intervals are low to intensely bioturbated with an assemblage of Siphonichnus, Schaubcylindrichnus, Diplocraterion, Arenicolites, Asterosoma, Skolithos, Rosselia, Conichnus, Bergaueria, Solemyatuba, Planolites, Thalassinoides, Chondrites and escape traces. The Mayaro delta front succession is cut across by a canyon dominantly filled with muddy prodelta deposits. The canyon fill deposits, which are devoid of any mesoscopic trace fossils, except a few rare burrow‐mottles. The canyon incision surface is characterized by colonization of a monospecific Glossifungites Ichnofacies. The main differences of this shelf‐edge delta with any typical wave‐influenced or river‐dominated shelfal delta are the extreme environmental stress factors at the shelf edge, arising from slope instability, high energy turbulence caused by hyperpycnal fluxes and oceanic waves, very high sedimentation (and erosion) rate, reduced salinity (especially closer to the distributary channel complex), occasional gravity flow processes and elevated turbidity.


25

JORDI M. DE GIBERT1

The Roots of Modern Shallow‐Marine Soft‐Bottom Benthic Communities:

An Ichnological Approach

1Universitat de Barcelona, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Martí Franquès s/n, 08028 Barcelona, Spain E‐mail: [email protected] Type of Presentation: Talk The evolution and diversification of metazoans in the Cambrian constituted a fundamental change in benthic ecosystems that initiated the evolutionary pathway leading to modern benthic communities. The agronomic revolution was the starting point for the evolution of burrowers, which was governed by the occurrence and extinction of burrowing taxa and behavioural strategies. This contribution attempts to analyze the ichnological record with the objective of recognizing for how long modern burrowing taxa have been playing a role in shallow‐marine soft‐bottom benthic communities. Most important marine burrowers today are mollusks (bivalves and gastropods), ‘worms’ (polychaetes, echiurans, enteropneusts), decapod crustaceans and echinoderms (irregular echinoids and holothurians). The task of recognizing their bioturbation in the fossil record faces the ‘classical’ ichnological difficulty of tracemaker identification. Neoichnological data, supported by good knowledge of Neogene and Pleistocene trace fossil counterparts, may allow to partly overcome that obstacle. At least some taxa within those groups produce traces bearing diagnostic characters that allow their identification in the fossil record. The stratigraphic distribution of trace fossils should allow evaluating the past history of some burrowing taxa. Thus, fossorial decapods and echinoids were a Mesozoic addition to benthic communities and they became well established as key burrowers during the Cretaceous. Mollusks and worms generally produce less diagnostic trace fossils and thus, there is greater difficulty in evaluating the presence of particular groups in ancient communities, although the first have an excellent body fossil record. Nevertheless, some groups seem to have followed a similar trend than decapods and echinoids, while others may have had a longer history being already part of Paleozoic benthos.


26

JORDI M. DE GIBERT1, H. ALLEN CURRAN2, RENATA G. NETTO

3, FRANCISCO W. TOGNOLI3 AND ZAIN BELAÚSTEGUI1

Burrowing Capabilities of Juvenile Thalassinideans: Paleobiological Significance of Ophiomorpha puerilis from the Pleistocene of the Bahamas and Southern Brazil

1Universitat de Barcelona Departament d'Estratigrafia, Paleontologia i Geociències Marines, Martí Franquès s/n, 08028 Barcelona, Spain 2Smith College Department of Geosciences Smith College Northampton, Massachusetts 01063, USA 3Unisinos Programa de Pós‐Graduação em Geologia, UNISINOS Av. Unisinos, 950 93022‐000 São Leopoldo RS, Brazil E‐mail: [email protected] Type of Presentation: Talk Ophiomorpha puerilis was first described to designate small (Ø=1.5‐3.5mm), pellet‐lined burrows, which occurred associated with large Ophiomorpha nodosa in the upper Pleistocene Chuí Fm of Osório (S Brazil). O. puerilis was characterized not only by its small size but also by bearing rod‐shaped, muddy pellets with rounded ends. The ichnospecies was interpreted as produced by juvenile thalassinideans, although the possibility of being produced by a different, commensal organism was not ruled out. This contribution describes two new occurrences of the ichnospecies, also associated with ‘normal size’ Ophiomorpha, in late Pleistocene limestones of the Bahamas. Material from Cockburn Town on San Salvador is similar to that from Brazil. O. puerilis specimens from Harry Cay on Little Exuma reach significantly larger diameters (Ø up to 12 mm) while retaining the same pellet morphology and texture of ‘typical’ O. puerilis. Thus, Ophiomorpha from this locality show a more or less continuous size distribution from O. puerilis to large Ophiomorpha isp. This new evidence supports the interpretation of O. puerilis, as being produced by juveniles of the same decapod species. No study is known to the authors regarding pellet‐lined burrows formed by modern juvenile thalassinideans, but several authors refer to tiny tunnels produced by juvenile callianassids and upogebiids emerging from burrows inhabited by adults. Although this scenario was used to interpret comparable trace fossil occurrences (e.g. Maiakarichnus, Sinusichnus, Thalassinoides), O. puerilis from Bahamas and Brazil present new data on burrow construction through thalassinidean ontogeny. Differences in pellet shape and texture between juvenile and adult burrows may be related to their capability to manipulate sediments of different grain sizes. Association between burrows of different diameters suggests that juvenile tunnels emerged from those of adults and/or that the path of smaller tunnels was ‘guided’ by pre‐existing burrows.


27

HURIYE DEMIRCAN1 AND DOĞAN USTA

2

Early Ordovician Trace Fossils from the Amanos Mountais (NE Osmaniye, SE Anatolia)

1Department of Geological Research, General Directorate of Mineral Research and Exploration (MTA), 06520, Ankara, Turkey 2General Directorate of Mineral Research and Exploration (MTA), Adana, Turkey

E‐mail: [email protected] Type of Presentation: Poster Trace fossils are found in the Lower Ordovician quartz arenite‐shale alternations, to the northeast of Osmaniye in southeastern Turkey. The sequence contains abundant, diverse and well‐preserved arthropod ichnofossil assemblages comprising nineteen ichnogenera (Arthrophycus isp., ?Circulichnis isp., Cruziana isp., Cruziana furcifera, Cruziana imbricata, Cruziana rugosa, Cruziana goldfussi, Deadulus isp., Didymaulichnus isp., Diplocraterion isp., Monocraterion isp., Monomorphichnus isp., Teichichnus isp., Skolithos isp., Palaeophycus isp., Planolites isp. Rusophycus isp. Protovirgularia isp., Trichophycus isp.). They are included in the Cruziana rugosa Group (Cruziana furcifera, C. goldfussi, C. rugosa) and can be used for chronostratigraphy throughout the Ordovician (Tremadocian to Arenigian). The presence of Cruziana furcifera, C. goldfussi, C. rugosa and ?C. imbricata in the studied section indicate that the unit is of Early Ordovician (Tremadocian‐Floian) age. These trace fossils belong to the shallow marine subtidal low‐energy Cruziana Ichnofacies. In the studied area, the sequence starts with slightly metamorphosed, Early Cambrian siliciclastic rocks, followed by Middle Cambrian carbonates and nodular limestone lenses (e.g. Doğan et al., 2011). They are followed by an alternation of meta‐sandstone, slate, quartz‐sericite‐chlorite schist, quartzite, quartzite‐chlorite schists of the early Upper Ordovician. The succession of trace fossil‐bearing meta‐pelitic rocks in the investigated area is overturned, based on the position of the trace fossils, which are observed at the top of bedding surfaces. This formation has been studied and named previously as the Seydişehir Formation (e.g. Dean and Monod, 1985). The Lower Ordovician siliciclastic facies in the Amanos area were dated using acritarchs in the lower part. The overlying thick and superimposed high‐frequency deposits, including Cruziana Ichnofacies suites, exhibit upper offshore and shallower conditions; an increasing frequency of Tigillites beds clearly illustrates shallowing conditions up to nearshore environments in the upper part of the formation (Ghienne et al, 2010). Our ichnofossil findings are from this upper part of the Seydişehir Formation. In the upper part of the Seydişehir formation, the alternating quartz sandstones with ripple marks and thin‐bedded shales include members of the Cruziana rugosa group. Due to its wide chronological range, some elements of this group display a restricted value as diagnostic Lower Ordovician forms in northern and western Gondwana.


28

ANDREI DRONOV1

Trace Fossils from the Ordovician Cool‐water Carbonates of St. Petersburg Region, Russia

1Geological Institute of Russian Academy of Sciences, Pyzhevsky per.7, 119017, Moscow, Russia E‐mail: [email protected] Type of Presentation: Poster Ordovician bioclastic limestones of St. Petersburg region are represented by cool‐water calcareous tempestites deposited in a storm‐dominated carbonate ramp environment in a shallow‐water part of the vast epicontinental basin of Baltoscandia. Due to low productivity of the ramp’s “carbonate factory” the succession is condensed with abundant discontinuity surfaces probably resulted from carbonate dissolution. The succession contains rich and diverse trace fossils assemblages which include Amphorichnus, Arachnostega, Balanoglossites, Bergaueria, Chondrites, Conichnus, Gastrochaenolites, Palaeophycus, Phycodes, Planolites, Thalassinoides and Trypanites. In general, the ichnodiversity is relatively low but trace fossils density can be very high on some levels. Major portions of the succession belong to the Cruziana ichnofacies with numerous omission surfaces demarcated by the Glossifungites and Trypanites ichnofacies. Abundance of hardground surfaces creates a high diversity of borers or organisms that were equally equipped for boring and burrowing. Balanoglossites and Gastrochaenolites often comprise both burrow and boring components. The region seems to represent a birth place for many Lower Paleozoic organisms adapted to boring strategy. Individual beds and bed sets as well as individual hardground surfaces which can be identified based on associated borings serve as an excellent markers for regional correlation.


29

SUZANNE C. DUFOUR1 AND REBECCA T. BATSTONE1

The Sulphide Mining Activities of Chemosymbiotic Thyasirid Bivalves 1Department of Biology, Memorial University of Newfoundland, St. John's, NL. A1B 3X9 Canada E‐mail: [email protected] Type of Presentation: Talk The family Thyasiridae consists of small infaunal bivalves that are common inhabitants of both deep‐sea sediments and shallower, organically enriched substrates. Within the family, some, but not all species maintain chemoautotrophic, sulphur‐oxidizing bacterial symbionts at the surface of their gills ‐ symbiotic thyasirids derive part of their nutrition from symbiont digestion. To drive carbon fixation, thyasirid symbionts require an oxidant and reduced sulphur; the host bivalve likely acquires these compounds by pumping water through its inhalant tube, and mining for sulphide, respectively. The sulphide mining behaviour consists of periodic extensions of the foot (which may extend up to 30 times the length of the shell) within surrounding sediments. Successive pedal extensions result in branched traces resembling Chondrites burrows. Here, we present observations made on: 1) the structure of thyasirid sulphide mining tracts under various experimental conditions; 2) redox changes induced by symbiotic thyasirids in the near‐burrow environment; and 3) patterns of ventilation through the inhalant tube. Based on these results, we propose a mechanism of sequential sulphide and oxygen uptake into the bivalve mantle cavity, and discuss implications for the interpretation of Chondrites fossils.


30

A. A. EKDALE1 AND JORDI M. DE GIBERT2

The Ups and Downs of Farming in a Tectonically Active Basin:

Late Miocene Agrichnia in the Vera Basin of Southeastern Spain

1University of Utah, Department of Geology and Geophysics, University of Utah, Room 383 FASB, 115 South 1460, East, Salt Lake City, UT 84112‐0102, USA 2University of Barcelona, Departament d'Estratigrafia, Paleontologia i Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Martí Franquès s/n, 08028 Barcelona, Spain E‐mail: [email protected] Type of Presentation: Talk Agrichnial (farming) trace fossils typically are found in deep‐marine environments within the Nereites Ichnofacies and commonly are observed in convex hyporelief on turbidite beds, where they are known as graphoglyptid burrows. The Vera Basin in the province of Almeria, southeastern Spain, was tectonically active throughout Miocene (and later) time. For a few million years from the late Tortonian to early Messinian, the basin received hemipelagic marl deposits that were punctuated by turbidite events. Soles of thin, turbidite sand beds preserve an abundance of pre‐depositional horizontal burrows, many of which are geometrically patterned agrichnia that are widely recognized as hallmarks of deep‐sea ichnocoenoses (Paleodictyon, Urohelminthoida, Helminthorhaphe). Post‐depositional burrows of crustaceans (Ophiomorpha) and echinoids (Scolicia) occur sparsely in some turbidites, but they are far out‐numbered by the pre‐depositional agrichnia. What makes this agrichnial trace fossil association of particular interest is that it occurred in a small, short‐lived, coastal basin that apparently never got more than a few hundred meters deep. As the basin opened up and flooded in the Late Miocene, the seafloor was colonized rapidly by tiny benthic farmers of uncertain biological affinity, who created networks of anastomosing or meandering tunnels, in which a nourishing food supply (probably bacteria or fungi) grew on mucus‐lined walls. The agrichnial assemblage in the Vera Basin is one of only a few examples of very young (less than 7 million years) graphoglyptid trace fossils and thus it serves to link the well‐known Cretaceous‐Paleogene record of such fascinating trace fossils with their elusive modern representatives observed in deep‐sea bottom photos and recovered in deep‐sea cores.


31

MAGDY EL‐HEDENY1, ABDEL GALIL HEWAIDY2 AND KHALID AL KAHTANY3

Shallow Marine Trace Fossils from the Callovian‐Oxfordian Tuwaiq Mountain Limestone and

Hanifa Formations, Central Saudi Arabia

1King Saud University Teachers College, KSA 2Al Azhar University, Faculty of Science, Egypt 3King Saud University, Science College, KSA E‐mail: [email protected] Type of Presentation: Poster The Callovian‐Oxfordian Tuwaiq Mountain Limestone and Hanifa formations of Central Saudi Arabia contain an assemblage of abundant trace fossils, including Chondrites intricatus Brongniart, 1828; Chondrites stellaris Uchman, 1999; Curvolithus simplex Fritsch, 1908; Hillichnus agrioensis Pazos and Fernández, 2010; Palaeophycus cf. tubularis Hall, 1847; Phycodes cf. palmatus Hall, 1852; Thalassinoides horizontalis Myrow, 1995; Thalassinoides suevicus (Rierh, 1932) and Thalassinoides isp. This assemblage is considered to belong to the Cruziana Ichnofacies. Traces of this assemblage have been described for the first time from this interval of the present area. Ethologically, the trace makers reflect a wide range of behaviours with chemichnia (Chondrites), domichnia (Palaeophycus), complex mining "domichnia/fodinichnia" (Thalassinoides), fodinichnia (Phycodes), repichnia (Curvolithus) and pascichnion and possible chemichnion (Hillichnus). The trace fossil association is comparatively richer in the Hanifa Formation than those recorded in the Tuwaiq Mountain Limestone Formation. The ichnogenus Thalassinoides is the dominant trace fossil and well distributed in the whole section. On the other hand, Chondrites is predominant in the marly limestone bed at the base of the Hanifa Formation. In the studied area, the Cruziana Ichnofacies reflects moderate to relatively low energy in infralittoral to shallow circalittoral substrates and below the fair‐weather wave base, but not storm wave base environments.


32

HAYLEY ESSEX1, DORRIK STOW1 AND IODP 339 SHIPBOARD SCIENTIFIC PARTY2

The Ichnology of Contourites: Examples from the Gulf of Cadiz

1Heriot‐Watt University Institute of Petroleum Engineering, Heriot‐Watt University, Edinburgh EH14 4AS, Scotland, UK 2IODP E‐mail: [email protected] Type of Presentation: Poster Contourite deposits are the product of the interaction between ocean bottom‐currents and deep sea‐floor ‐ in areas where bottom‐currents are focussed erosive features are usually developed but when the velocity decrease depositional feature are dominant, in some case with large dimensions. These deposits are notorious for being thoroughly bioturbated. However, ichnological data can be a very useful tool to interpret deep‐sea environmental conditions and to date very few studies have been published looking at the ichnology of contourites. The Gulf of Cadiz and surrounding regions are valuable areas of research as significant environmental data can be gained from their study, as well of the identification of ichnological features, which may aid the identification of contourite deposits in the Pliocene and Quaternary sedimentological record. The study of ichnofossils in contourites is difficult, as few good examples exist on land in exposures, therefore study is largely constrained to marine sediment cores. Ichnofossils in cores are challenging to identify as they are viewed in cross section and generally show poor contrast against the background sediment. Therefore techniques such as X‐radiography and CT scanning are used to gain a clearer picture of the internal structure of the core to assist in the identification of biogenic structures. IODP expedition 339 took place in November 2011 – January 2012 and six sites were drilled in the Contourite Depositional System (CDS) of the Gulf of Cadiz and west off Portugal. In this contribution, current ichnological research from these sites is presented.


33

DIANA ELIZABETH FERNÁNDEZ1 AND PABLO JOSÉ PAZOS1

Nereites‐like Trace Fossils in Lower Cretaceous Marginal Marine Environments from

Patagonia: Preservational Variants and Ichnotaxonomic Discussion

1University of Buenos Aires, Instituto de Estudios Andinos "Don Pablo Groeber"(IDEAN – CONICET), Dpto. de, Ciencias Geológicas. Ciudad Universitaria, Pabellón II (1428), Buenos Aires, Argentina E‐mail: [email protected] Type of Presentation: Poster Epichnial, winding to meandering structures with an inner area or median tunnel enveloped by an outer zone of reworked sediment, assignable to Nereites Macleay, are described. The material comes from the Lower Cretaceous Agrio and Mulichinco Formations (Neuquén basin, Patagonia, Argentina). It was found in marginal‐marine deposits, with either wave ripple lamination or combined‐flow structures and sometimes in association with Asteriacites von Schlotheim or Bolonia Meunier. These burrows display three distinguishable morphotypes which, following previous authors’ recommendations, are referred to informally as preservational variants of Nereites. In Nereites Morphotype A, a median meniscate tunnel and an outer lobate to diffuse zone is observed. This morphotype resembles N. missouriensis in its “lobate form”. Nereites Morphotype B presents a lobate outer zone and a core of discrete uniserial pustules sometimes converging into a uniform tunnel. This morphotype is similar to Nereites missouriensis (Weller) ivar. phyllodocites Geinitz when discrete pustules are distinguishable and to Nereites jacksoni Emmons when pustules converge. In Nereites Morphotype C, only the core is preserved, as a uniserial chain of pustules. This morphotype resembles Nereites missouriensis var. uniserialis, or Nereites isp. preservational variation Neonereites uniserialis. Given its epichnial preservation, it might be considered as Nereites missouriensis in a “pearl chain form”; the lack of a connecting string disregarded an assignment to Hormosiroidea Schaffer. Intergradation between morphotypes is observed. In agreement with previous authors, it is considered here that: a) Neonereites Seilacher is a preservational variant of Nereites; b) these preservational variants are not originated by changes in behaviour, but most likely by toponomic relationships and taphonomic biases; and c) the most plausible producers are, in this case, arthropods.


34

DIANA ELIZABETH FERNÁNDEZ1 AND PABLO JOSÉ PAZOS1

Enhanced Preservation of Delicate Arthropod Trackways by Microbial Mat Biostabilisation in a

Cretaceous Marginal‐Marine Setting from Patagonia: A Preliminary Study

1University of Buenos Aires, Instituto de Estudios Andinos "Don Pablo Groeber"(IDEAN – CONICET), Dpto. de, Ciencias Geológicas. Ciudad Universitaria, Pabellón II (1428), Buenos Aires, Argentina E‐mail: [email protected] Type of Presentation: Talk Observations in several localities of the Lower Cretaceous Agrio Formation (Neuquén basin, Patagonia, Argentina) during recent years confirmed that marginal‐marine environments were widespread. Particularly, the top of the unit has recently been documented as a tidally dominated depositional setting. In the interval studied here, intertidal conditions occurred on a tidal flat. The analysis of sandstone beds in different areas permitted the identification of exquisite trackways preserved on ripples prior to exposure. Some are assignable to xiphosurids (Kouphichnium isp.), while others are well‐preserved but lacking in features diagnostic of the producers, which are nevertheless most likely arthropods. Microbially induced sedimentary structures (MISS) and therefore, the presence of microbial mats, are known from tidal flats. The presence of wrinkle marks (a type of MISS) on the trackway‐bearing levels pointed towards the involvement of microbial mats. Samples of the surface of these levels were taken and photographed under a scanning electron microscope (SEM). Between the sand particles of the uppermost millimetres of the surface, filament‐like microstructures were observed, mostly oriented parallel to the surface and laterally continuous, but also some perpendicular to the bedding plane. They resemble ensheathed forms of cyanobacteria, a common morphotype involved on mat and biofilm formation commonly described in tidal flats. After this preliminary analysis, it was found that the existence of delicate arthropod trackways coincides with these filamentous mats, which are considered a necessary condition for the exceptional preservation of the traces, through the binding and biostabilisation of the layer, preventing erosion. Future studies will go into greater detail on the specific role microbial mats play in trace fossil preservation in these Cretaceous marginal‐marine settings.


35

ROZALIA FODOR1 AND DAVID ARPAD2

Ichnology of an Early Miocene Siliciclastic Succession (Dédestapolcsány, North‐Hungary)

1Matra Museum, Kossuth u. 40, H‐3200 Gyöngyös, Hungary 2Karoly Eszterhazy College, Leanyka u. 6., H‐3300 Eger, Hungary E‐mail: [email protected] Type of Presentation: Talk The locality – a former sandpit – is situated at the boundary of the Bükk and Uppony Mountains in the vicinity of Dédestapolcsány village. The sediments of the exposure belong to the Garab Schlieren Formation. The sandpit can be divided into four well‐recognizable sedimentological units. Each unit has a special trace fossil assemblage. Going upward the following units can be distinguished. The succession begins with a 50 cm thick swaley cross‐stratified sand with intercalations of thin mud‐drapes. There are small lenses of Macaronichnus isp. within the sand‐body. The bioturbation index of this unit is 1. The second unit is a one meter thick, cross‐stratified sand containing cracked clay laminae. Poorly preserved Ophiomorpha nodosa and Thalassinoides isp. occur in great abundance in this second unit. The bioturbation index of this unit is 4. The third unit is a 1.5 m thick limonitic sand with marl intercalations. Its trace fossils are the most diverse. There are Paleophycus isp., Teichichnus isp. and Phycoderma isp. in the sand, while the marl contains Thalassinoides isp. and Planolites isp. The bioturbation index of this unit is 3. The fourth unit; the uppermost part of the sandpit, is a three meters thick, cross‐stratified limonitic sand poor in trace fossils: Ophiomorpha isp. and Teichichnus isp. The locality gives an example of a mixed Skolithos and Cruziana Ichnofacies. The trace fossils imply deposition in a wave‐dominated estuary environment which is stratigraphically succeeded by deposition in estuary mouth to bay‐head delta settings.


36

ROSANA GANDINI1 AND RENATA G. NETTO

2

Ophiomorpha from Lower Permian Sandstones of Southern Brazil

1USP, Instituto de Geociências, Programa de Pós‐graduação em Geoquímica e Geotectônica Rua do Lago, 562, Cidade Universitária, 05508‐080 São Paulo SP, Brazil 2UNISINOS, Programa de Pós‐graduação em Geologia Av. Unisinos, 950, 93022‐000 São Leopoldo RS, Brazil E‐mail: [email protected] Type of Presentation: Poster Ophiomorpha is one of the commonest trace fossils preserved in the geological record from the Mesozoic onwards and corresponds to thalassinidean burrow systems excavated preferentially in shallow marine settings. Seven ichnospecies were diagnosed, based on the morphology and arrangement of pellets in the wall. This work reports the occurrence of pelleted lining burrows in Lower Permian sandstones of the Paraná Basin (southern Brazil) attributed to Ophiomorpha. The burrow lining is composed of tiny ovoid pellets, sparsely arranged around the burrow border, forming a delicate wall. Burrow diameter ranges from 8 to 13 mm. Dichotomous branching and secondary openings constructed after erosion of the original shaft were observed. Ophiomorpha was previously recorded in Permian deposits from Utah (USA); however, these structures seem to be to be inorganic (A.A. Ekdale, pers. comm.). Also, Ophiomorpha has been observed in Permian sandstones from Oman, India, Australia and China, but without information about pellet morphology. The pattern of pellets of the Lower Permian Ophiomorpha from Brazil mixes characteristics observed in burrows made by juvenile (O. puerilis) and opportunistic (O. rudis) tracemakers. The analysis of this morphological pattern may contribute to a better understanding of the evolutionary trends of the thalassinidean behaviour in the Late Paleozoic.


37

MICHAEL GARTON1 AND DUNCAN MCILROY2

Feeding Trails and Mass Migrations: Large Arthropod Traces from the Early Cambrian of

North‐West Scotland 1University of Liverpool, Dept. of Earth and Ocean Sciences, Brownlow Street, Liverpool L69 3BX, United Kingdom 2Memorial University of Newfoundland, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada E‐mail: [email protected] Type of Presentation: Talk Arthropod populations coexisted with the oscillatory character of the early Cambrian transgression. Their behavioural responses are illustrated by abundant, large arthropod trace fossils in the Eriboll Sandstone Formation of NW Scotland. A new style of nektobenthic arthropod trace fossil, formed by winnowing, is described. The arthropod traces exhibit strong rheotaxis. They are always associated with Skolithos. Lines of Rusophycus from one individual settling on successive ripple crests indicate that the Rusophycus is a surface (rather than infaunal) trace. Forward adjusting Rusophycus grade into larger areas with multiples of the characteristic coffee bean impression, interpreted as surfaces winnowed by arthropods swimming immediately above the substrate, washing out sedimentary ripples. Where arthropods settled to winnow channels, there are Rusophycus‐like beginnings and endings to their shallow trails. In between, the underbody winnowing generated an animal induced cross‐lamination. In the absence of strong bottom currents their winnowed channels loop and crosscut. They are excavated in well‐washed, coarse‐grained to granular sand that is unlikely to have been able to sustain large animals through sediment mining. The circumstantial evidence is strong that the Skolithos tracemaker was prey for arthropods using a winnowing technique that modern flatfish demonstrate is a viable strategy for hunting endobenthonic prey. Approaching one maximum flooding surface, the winnowed channels change from looping to linear. Traceable along the 180 km length of outcrop they and large Cruziana both indicate movement towards the WNW (or in Cambrian terms, towards the Laurentian continent). By analogy with modern arthropods, the absence of juveniles is compatible with populations of adults moving landward to mate and moult.


38

V. GAUR1 AND V.S. PARIHAR1

New Record of Trace Fossils from the Nagaur Sandstone of Marwar Supergroup, Dulmera

Area, District‐Bikaner, Rajasthan, India

1Department of Geology, Faculty of Science, Jai Narain Vyas University, Jodhpur ‐ 342005, Rajasthan, India E‐mail: [email protected] Type of Presentation: Talk Three new well‐preserved trace fossils (Arenicolites isp., Scoyenia isp. and Gyrophyllites isp.,) are reported from the Nagaur Sandstone of the Marwar Supergroup, the upper (youngest) group of the Marwar Supergroup. The Marwar Supergroup is a 1000m thick lithostratigraphic unit that occupies a large area of north western Rajasthan and unconformably overlies on 779‐681 Ma old Malani Igneous Suite. It is sub‐divided in the three groups: the lower Jodhpur Group; middle Bilara Group and upper Nagaur Group. The Jodhpur and Nagaur Group are arenaceous and argillaceous sequences and the Bilara Group is a calcareous sequence. The Nagaur Group is sub‐divided in two formations, the lower Nagaur Sandstone Formation and the upper Tunklian Sandstone Formation. The lithologies of the Nagaur Sandstone Formation are brick red sandstone, siltstone, red shale and greenish clay bands with cross bedding, parallel bedding and ripple marks. The trace fossils are found in red shale to red siltstone lithofacies in the Dulmera area, which is the upper part of the Nagaur Sandstone and the area is located about 65‐70 kilometers northeast of Bikaner. These trace fossils are assigned to Arenicolites isp. (U‐shaped dwelling burrows), Gyrophyllites isp. (produced by an animal that made repeated probe into the sediments in a radial pattern) and Scoyenia isp. (made by arthropods). These ichnogenera demonstrate a shallow‐marine to non‐marine depositional palaeoenvironment. No age can be assigned on the basis of these trace fossils as they range from Cambrian to Recent, but trilobites trace fossils were already found here by Kumar & Pandey, 2008 and suggest that the Nagaur Sandstone Formation is of Early Cambrian age.


39

STACEY GIBB1, S. GEORGE PEMBERTON

1 AND BRIAN D.E. CHATTERTON1

A Trace in Every Port: Rusophycus carleyi Group

1University of Alberta, Department of Earth & Atmospheric Sciences, University of Alberta Edmonton, AB, T6G 2E3, Canada E‐mail: [email protected] Type of Presentation: Talk Arthropod traces, especially Cruziana ichnospecies, have been suggested as useful chronostratigraphic tools for the Paleozoic of Gondwana. Rusophycus carleyi and similar morphological traces, R. morgati, R. polonicus, R. radialus and R. moyensis, have been found in a number of localities throughout the world: Argentina, Australia, Canada, France, Libya, Morocco, Poland, Spain, Wales and the USA, therefore a global distribution. Their geological range was from the late Cambrian (Furongian) to the Late Ordovician. Rusophycus carleyi, from southeastern Morocco, was definitively linked to the trilobite Asaphellus aff. fezouataensis. The other Rusophycus ichnospecies listed above have also been correlated with asaphide trilobites, with the exception of R. moyensis that has been associated with an olenid trilobite. Asaphide protaspides are known for their large size, non‐adult‐like form and multiple instars, suggesting that they were long‐lived and planktonic. Thus these arthropods had considerable potential for dispersing widely.


40

SHWETA S. GURAV1 AND KANTIMATI G. KULKARNI1

Schaubcylindrichnus in the Assilina Limestone Member (Ypresian) Naredi Formation, Kachchh,

India

1Geology and Palaeontology Group, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004 E‐mail: [email protected] Type of Presentation: Talk Yellowish marls of the Assilina Limestone Member, Naredi Formation (Ypresian) exposed in the western part of Kachchh region of Gujarat, India show abundant development of Schaubcylindrichnus. This Eocene form shows diagnostic characters such as the presence of a filter funnel and a loose sheaf of converging tubes with a thick lining. Each tube lining was emplaced using the larger foraminifer Assilina; arranged in an imbricate manner. However, the inner lining is smooth being made up of very fine‐grained sand. The dissimilarity in the constitution of the wall lining as compared to that observed in the forms reported from other basins is a probable consequence of substrate nature. This morphological anomaly may thus be considered as a mere ecological variation. Also, it indicates that the producer was capable of selective sorting. The fine‐grained inner lining was constructed in order to regulate conditions within the burrow as the substrate is coarse‐grained. Fecal mounds generally associated with Shaubcylindrichnus are found to be absent. The associated ichnofauna consists of Thalassinoides, Palaeophycus and Rhizocorallium. The bivalves within this member show presence of sponge borings (Entobia). Environmental conditions such as clear waters, low turbulence and slow rate of sedimentation are implicit from these sponge borings. The Schaubcylindrichnus‐bearing strata correspond to the shallow benthic zone SBZ 11, plankton zones P8 and P9, and the Assilina granulosa zone reported previously. The foraminiferal assemblage also suggests 20‐30 m paleobathymetry.


41

DARIO HARAZIM1, DUNCAN MCILROY1, NICOLAS EDWARDS2,

ROY WOGELIUS2 AND UWE BERGMANN

3

The Biogeochemical Effect of Bioturbation: A Perspective from the Rock Record

1Department of Earth Sciences, Memorial University, St. John’s, NL, A1B 3X5, Canada 2Williamson Research Centre for Molecular and Environmental Science, University of Manchester, Manchester M13 9PL, UK

3SLAC National Accelerator Laboratory, Linac Coherent Light Source, Menlo Park, CA 94025, USA

E‐mail: [email protected] Type of Presentation: Talk Modern bioturbated sediments reveal a three‐dimensional organization of geochemical fluxes, largely confined to discrete microenvironments such as pockets of reactive organic carbon and macrofaunal burrows. Traditional one‐dimensional diagenetic models lack the sophistication necessary to accurately describe this heterogeneity. Well‐preserved samples containing Phycosiphon incertum from the Late Cretaceous Rosario Formation, Mexico, were investigated using an interdisciplinary approach that combines conventional petrography (SEM), geochemical measurements (ICP‐MS, EA, SRS‐XRF) to investigate the role of macrofaunal sediment ingestion on potential biogeochemical changes in fine‐grained siliciclastic sediment. TOC values were found to be slightly enriched in the burrow core of P. incertum compared to halo and host sediment. The core shows significantly enriched values in redox‐sensitive transition elements as well as major elements. Stable isotope values of carbon were found not to vary significantly between burrow core, halo and host sediment. Three‐dimensional compartmentalization of natural sediment by size‐dependent sorting of sedimentary components is proposed as an important, yet little considered control on biogeochemical reactions and their reaction products stored in the rock record.


42

DANIEL HEMBREE1, JARED BOWEN

1, ANGELINE CATENA1 AND NICOLE DZENOWSKI1

Improving the Interpretation of Continental Ichnofossils Through Experimental Neoichnology

of Modern Soil Animals

1Ohio University, Department of Geological Sciences, 316 Clippinger Laboratories, Athens, OH 45701 E‐mail: [email protected] Type of Presentation: Talk Modern soils contain diverse ecosystems that include micro‐ and macrofauna engaged in behaviours that produce abundant and distinct biogenic structures. Our knowledge of the biogenic structures produced by modern continental organisms is limited, however, making the interpretation of continental ichnofossils difficult. This inhibits our understanding of ancient soil ecosystems despite the presence of ichnofossils in even Early Paleozoic palaeosols. This project involved the study of three scorpion species, one whip scorpion species, three millipede species, one centipede species, two salamander species and two skink species. The animals were placed in sediment‐filled terrariums for up to thirty days during which their behaviours and resulting biogenic structures were observed. Biogenic structures produced in the terrariums included subsurface burrows and chambers, soft sediment deformation structures, as well as surface tracks and trails. Open burrows and surface structures were cast with plaster while soft sediment deformation structures were preserved with a sodium silicate solution. Descriptions of the subsurface structures included basic architecture, bioglyphs, depth, slope, total length, tunnel width, height and circumference, complexity and tortuosity. The biogenic structures included a diverse assemblage of shafts, ramps, U‐, J‐ and Y‐shaped burrows, helical burrows, mazeworks and boxworks. On average, each species produced three distinct morphologies although there was significant overlap in basic burrow architectures between taxonomic groups. The quantitative aspects of the burrow morphologies were compared using nonparametric statistics to determine if the burrow casts could be differentiated based on tracemakers, behaviours and environmental conditions. The results from these experiments provide a vital data set for assessing the paleoecology of ancient soil ecosystems through the improved interpretation of continental ichnofossil assemblages.


43

LIAM HERRINGSHAW1 AND DUNCAN MCILROY2

The Fossil Record of Bioirrigation

1Department of Earth Sciences, Durham University, South Road, Durham. DH1 3LE 2MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Talk Most burrow‐dwelling organisms in marine environments ventilate their burrows to permit long‐term occupation. This process – bioirrigation – removes waste material and replenishes nutrients, and also creates habitats for other organisms within and surrounding the burrow. It therefore has an extremely significant impact upon endobenthic ecology. The sedimentological effects of bioirrigation are little‐known, however, and its palaeoecological record has never been studied. This is despite numerous common ichnotaxa, such as Ophiomorpha, Polykladichnus and Thalassinoides, representing fossil examples of burrow networks that must have been bioirrigated. Using an integrated, experimental approach combining laboratory microcosms with fieldwork and petrological analysis, we here present the first detailed assessment of the ichnological record of bioirrigation, its origins, evolution and ichnological significance. We are also able to demonstrate, for the first time, the transportation of clay‐grade particles into the pore networks of siliciclastic sediments during bioirrigation. In laboratory microcosms, particles of kaolinite clay were found to be transported advectively into pore spaces along the interface between two buried sand layers by the burrow‐ventilating activities of the mud shrimp Upogebia pugettensis. The term ‘bioinfiltration’ is introduced to describe the process, and its occurrence in the fossil record examined.


44

KENTARO IZUMI1

Geochemical Analyses of the Trace Fossil Phycosiphon incertum from Lower Jurassic Shelf Deposits: Implications for the Mineral Selection Preferences of its Tracemaker

1Department of Earth and Planetary Science, The University of Tokyo Science Bldg. #1, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo, 113‐0033, Japan E‐mail: [email protected]‐tokyo.ac.jp Type of Presentation: Talk Geochemical analyses of the trace fossil Phycosiphon incertum demonstrate the specific mineral selection preferences of its tracemaker. Samples of P. incertum were obtained from the Lower Jurassic shelf deposits (Higashinagano Formation) in the Toyora area, southwest Japan. Optical microscopic observations show the absence of any diagenetic features such as rust in the core and surrounding halo of P. incertum and in the host sediment. Elemental analysis revealed that the core and halo of P. incertum have significantly different compositions; relative to aluminium, a reliable index of aluminosilicate content, potassium is higher in the core than in the halo. X‐ray diffraction analysis has revealed that the constituent minerals of the silty mudstone in the Higashinagano Formation are quartz, plagioclase, calcite and clay minerals (smectite, illite and kaolinite). Accumulation of potassium contents in the core strongly suggests that the Phycosiphon‐producer selectively ingested fine‐grained illite particles and avoided other coarser mineral grains when feeding on subsurface deposits; this conclusion is based on the fact that the only mineral containing substantial amounts of potassium is illite. This feeding strategy might have enabled the Phycosiphon‐producer to intake organic matter effectively from the subsurface sediment, in which organic matter consisted mostly of refractory material that could not be utilized by marine benthos. The geochemical approach here applied to P. incertum should have broad utility because it is applicable to other phycosiphoniform burrows.


45

SÖREN JENSEN1, LUIS A. BUATOIS2 AND M. GABRIELA MÁNGANO2

Testing for Palaeogeographical Patterns in the Distribution of Cambrian Trace Fossils

1Área de Paleontología, University of Extremadura, Avenida de Elvas s/n, ES‐06006 Badajoz, Spain 2Department of Geological Sciences, University of Saskatchewan, 114 Science Place, SK S7N 5E2 Saskatoon, Canada E‐mail: [email protected] Type of Presentation: Talk Invertebrate‐produced ichnofossils have not been widely used in palaeogeographical studies. The most obvious reason for this is that trace fossils are not producer‐specific and many simple trace fossils such as Skolithos are made by a wide range of producers. Trace fossils with a restricted palaeogeographical distribution are therefore generally restricted to ichnotaxa that show features of the producer that are sufficiently distinctive to reduce, if not eliminate, convergent morphologies. The best‐known examples are provided by arthropod trace fossils, such as the lower Palaeozoic Cruziana stratigraphy. We examine the palaeogeographical distribution of selected Cambrian trace fossils. Astropolichnus hispanicus, Climactichnites, Syringomorpha nilssoni and early examples of Paleodictyon all have a restricted palaeogeographical distribution, likely representing that of their producers. A cosmopolitan distribution is seen in Didymaulichnus miettensis and in early examples of Rusophycus and Dactyloidites. However, age resolution is uneven, complicating the establishment of patterns. Oldhamia shows a wide distribution in lower Cambrian deep‐sea sediments, although that of Oldhamia geniculata is restricted. Several of these trace fossils do not show producer‐specific details but are morphologically relatively complex and may also be early representatives of their type.


46

SÖREN JENSEN1, TEODORO PALACIOS1, CARLOS NETO DE CARVALHO2 AND PEDRO MARTINS

2

Trace Fossils and Acritarchs from the Colorada Formation (Upper Ordovician?), Ossa‐Morena

Zone, SW Iberian Peninsula

1Área de Paleontología, Universidad de Extremadura, Avenida de Elvas s/n, ES‐06006 Badajoz, Spain 2Geopark Naturtejo da Meseta Meridional and Municipality of Idanha‐a‐Nova, Centro Cultural Raiano, Av. Joaquim Morão, 6060‐101 Idanha‐a‐Nova, Portugal E‐mail: [email protected] Type of Presentation: Poster The sandstone‐dominated Colorada Formation crops out in the border region of Spain and Portugal in the Ossa‐Morena Zone. It overlies the Middle Ordovician “Xistos com Phyllodocites” Fm., with ichnogenera such as Nereites and Dictyodora and is capped by graptolite‐rich shales of the basal Silurian “Xistos com Nódulos” Fm. We report the first acritarchs from the Colorada Formation, which include Villosacapsula setosapellicula, Deunffia sp. and Orthosphaeridium sp., from the middle and upper part of the formation. This, combined with other age constraints, suggest a Late Ordovician age, without further precision, for all or most of the formation. Earlier reports of trace fossils are largely limited to Skolithos and Planolites‐type burrows and intense bioturbation. Endichnial trace fossils from the lower part of the Colorada Formation, reaching 20 cm in diameter, consist of numerous ribs that radiate, typically in the outline of a semicircle, from a wide smooth central area. Individual ribs are regularly or somewhat irregularly arranged and more or less clearly curved in the vertical plane. Similar forms from the Ordovician of Ireland and the Isle of Man have been described as ichnospecies of Glockerichnus, but these trace fossils probably all belong to a different ichnogenus and Stellascolites Etheridge, 1876, comes into consideration. Arthropod‐type trace fossils from the lower part of the Colorada Formation include 2‐4 cm wide, mostly straight, Cruziana furcifera and C. cf. almadenensis, with faintly developed longitudinal scratch‐marks meeting the central furrow at very acute V‐angles, some with clear evidence of tunneling. A possible new ichnospecies of Rusophycus is characterized by a steeply inclined triangular anterior portion, probably the result of multiple phases of tail‐down burrowing. The Colorada Formation trace fossils provide a rare example of an Upper Ordovician? ichnoassemblage from the Ossa‐Morena Zone and is also of interest because of the unusual combination of ichnotaxa.


47

HENDRIK KLEIN1 AND SPENCER G. LUCAS2

The Late Triassic Phytosaur Ichnotaxon Apatopus lineatus (Bock, 1952) and Other Footprints

That Demonstrate Parallel Evolution of the Semi‐aquatic Lifestyle in Archosaurs

1Saurierwelt Paläontologisches Museum, Alte Richt 7, D‐92318 Neumarkt, Germany 2New Mexico Museum of Natural History, 1801 Mountain Road NW, Albuquerque, NM 87104‐1375 E‐mail: [email protected] Type of Presentation: Talk The tetrapod ichnotaxon Apatopus lineatus was first described from the Norian Passaic Formation (Newark Supergroup) of New Jersey, North America. Later it was documented, for example, from the Chinle Group of the western USA. New discoveries from Europe and North Africa indicate a Pangea‐wide distribution of Apatopus lineatus, as do the skeletal remains of the probable trackmaker, the semi‐aquatic phytosaurs. New definitions of crurotarsan groups suggest a long phytosaur ghost lineage extending back to the Middle or Early Triassic with a preceding terrestrially‐adapted stage. This is similar to developments in crocodylomorphs ‐‐Batrachopus and Crocodylopodus footprints respectively‐‐in the Late Triassic‐Jurassic. By its morphology and temporal distribution from Early to Middle Triassic, the ichnogenus Synaptichnium matches a hypothetical ancestor of semi‐aquatic phytosaurs/Apatopus. Features shared by Synaptichnium and Apatopus are: (1) elongate pes imprints, digits increasing in length from I to IV, digit IV longest, (2) extended, antero‐laterally directed digit V, (3) relatively large manus, digit III longest and (4) relative position/orientation of imprints. Differences concern the compact metatarsal‐phalangeal axis in Synaptichnium due to cursorial habits, whereas Apatopus has a crocodile‐like appearance. Archosaurian adaptation to aquatic environments took place in parallel in proterosuchids, phytosaurians, poposauroids and crocodylomorphs, possibly controlled by climatic‐ecological constraints.


48

DIRK KNAUST1, MICHAŁ WARCHOŁ1 AND IAN KANE1

Ichnology in Reservoir Characterization of Turbidites:

Lessons Learned from Outcrop Studies

1Statoil 4035 Stavanger, Norway E‐mail: [email protected] Type of Presentation: Poster Ichnological methods have been successfully applied in numerous studies of shallow‐marine deposits, while the application of ichnology to reservoirs in deep‐marine environments is still in its infancy. Although advanced concepts exist to differentiate architectural elements of fan deposits in outcrop, their application to subsurface cases is hampered because of contrasting kinds of data: in outcrop, trace fossils preferentially occur parallel to bedding and can be observed in three‐dimension, whilst core sections display two‐dimensional ichnofabrics normal to bedding. Eocene to Oligocene turbidites are exposed in the Grès d’Annot Basin in SE France and were investigated as an analogue to explain depositional trends of confined turbidites in Cretaceous reservoirs in the Norwegian Sea and elsewhere. The distribution of pre‐turbidite versus post‐turbidite trace fossils was studied in several outcrops along a proximal‐distal transect. As the quality and quantity of shallow burrow preservation is related to the amount of erosion by the turbidity current, a semi‐quantitative analysis of pre‐ versus post‐turbidite trace fossils was performed in connection with detailed sedimentological investigations. In addition, the relationship of significant ichnofabrics to individual lithofacies types and assumed sub‐environments was investigated. Well core material from the Vøring Basin, offshore Norway, comprises intervals with moderate to intense bioturbation. Special attention was paid to the recognition and distribution of post‐turbidite burrows as these are almost the only category of trace fossils visible in vertical core sections. Careful analysis of significant burrow features from outcrop enables the identification of such ichnotaxa in core and furthermore utilizes their value in the reconstruction of sedimentary environments. This study illustrates the verification of ichnological methods in the analysis of deep‐sea deposits as an integrated part of reservoir characterization.


49

DIRK KNAUST1

Trace Fossil Classification:

Where are We? Can We do it Better? Does it Matter?

1Statoil 4035 Stavanger Norway E‐mail: [email protected] Type of Presentation: Talk The application of trace fossil studies to sedimentological investigations, particularly the reconstruction of depositional environments, is largely dependent on the exact recognition of ichnotaxa. The lack of a consistent classification scheme for trace fossils often hinders integrated studies in which ichnological information is fully employed in sedimentological analysis. Our current basis for taxonomical and systematic work of invertebrate trace fossils is the Treatise on Invertebrate Paleontology, Part W, compiled by Häntzschel (1975) and listing ichnogenera in alphabetical order. Since then, the number of ichnogenera has been more than doubled and it becomes increasingly difficult to keep track of the continual growing number of new ichnotaxa. An overload of ichnotaxonomical data without a proper classification hinders a transformation of this information into knowledge. Today, many workers have adopted an ethological classification for trace fossils, although this may mislead environmental analysis in cases where incorrect assumptions on the ethology of trace fossils were made. A new classification scheme, based on significant morphological features (ichnotaxobases), is proposed for major trace‐fossil groups, such as burrows, bioerosional trace fossils, trackways, imprints and trails. In a critical review, all treated ichnogenera are listed together with recent references for more detailed data. Even those ichnogenera regarded as invalid and not included in the Treatise are listed with references. Burrows are by far the largest group of invertebrate ichnogenera (60%), followed by bioerosion trace fossils (16%), trackways (15%), imprints (5%) and trails (4%). The new classification scheme is intended to serve as a solid basis for further ichnotaxonomical work towards a more stable trace‐fossil systematics. As a next step it could be the basis of a searchable online database in which further criteria of ichnogenera may be regarded and filtered.


50

RICHARD J. KNECHT1 AND JACOB S. BENNER2

Contemplating Cubichnia: No Time to Rest

1Harvard University, Museum of Comparative Zoology, Departments of Vertebrate and Invertebrate Paleontology 26 Oxford Street, Cambridge, Massachusetts 02138, USA 2Tufts University, Department of Earth and Ocean Sciences, Lane Hall, Medford, Massachusetts 02155, USA E‐mail: [email protected] Type of Presentation: Poster Ethological categories (as parataxonomies) for trace fossils were first suggested by Seilacher in 1953. The original proposal consisted of five categories: cubichnia (resting), domichnia (dwelling), fodichnia (feeding), pascichnia (grazing) and repichnia (locomotion). Since then, the ethological classification has been modified and expanded with the present number of categories at fourteen and several additional subcategories. The category cubichnia has remained relatively unchanged since its inception and is commonly referred to as “resting traces”, or more aptly put, a temporary cessation of locomotion. However, these two criteria of cubichnia, resting (as an ethological interpretation) and temporary immobility (as a temporal interpretation), are neither definable nor quantifiable within the trace fossils themselves and therefore invalidate cubichnia as an ethological category. Ethologically, the term ‘resting’ has been shown to be misleading. Seilacher calls it a “misnomer”, citing its confusion with a “purpose” instead of the “activities by which they are made”. Others have thoroughly demonstrated alternate possible behaviours that can and do occur while an organism is in situ (e.g. hiding, rehydration, respiration, heat absorption, scent transmittal, ectoparasite removal, etc.). Of all valid described arthropod resting traces (excluding Rusophycus/Isopodichnus), majority of the ‘cubichnia’ are attributed to locomotion, grazing, feeding, or escape behaviours; essentially they are repichnia, pascichnia, fodichnia and fugichnia. While it is easily shown that a ‘resting’ trace can be the result of many different behaviours we must be careful not to make this a case of semantics. Assuming that most ichnologists agree with the multi‐ethological nature of cubichnial traces, the temporal aspect of cubichnia—which is arguably its more colloquial usage—must also be addressed. Temporary immobility begs the question, ‘what is temporary?’ More importantly, how does one interpret a complete cessation of movement from a trace fossil? The partial imprint of ventral anatomy is unquestionable evidence of the tracemaker in that place for ‘some’ time but can the duration of that time be quantified? The reality is that cubichnia can be made when an organism remains in place for any amount of time, whether it is the assumed longer duration of a ‘resting’ period or in a period of seconds or less. Even suggesting a trace is the result of stationary behaviour of an organism is largely a question of interpretation.


51

If the two characteristics of cubichnia, ‘resting’ and ‘cessation of locomotion’, are shown to be irretrievable data within trace fossils, cubichnia no longer is useful as an ethological category and should be removed from the classification scheme. It is suggested that cubichnia be renamed cubichniforma and used solely as a morphological category of description, regardless of ethology and defined as an imprint revealing the partial latero‐ventral anatomy of the tracemaker. This new definition is arguably how the term cubichnia is already used in practice.


52

VERÓNICA KRAPOVICKAS1, MARÍA GABRIELA MÁNGANO2 AND CLAUDIA A. MARSICANO

1

Continental Ichnofacies Models: The Role of Tetrapod Tracks

1IDEAN‐CONICET. Departamento de Ciencias Geológicas, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires Ciudad Universitaria, Pabellón 2, Buenos Aires, C1428EHA, Argentina E‐mail: [email protected] Type of Presentation: Talk Traditionally focused on invertebrate trace fossils, the ichnofacies model provides a conceptual context to understand the paleoenvironmental significance of trace fossils. Recently it has been expanded to include tetrapod footprints and five archetypal tetrapod ichnofacies were defined for continental and coastal‐plain environments. However, controlling environmental parameters that affect ichnofacies distribution have not been discussed. An integrative perspective was employed to tackle this problem, taking into account depositional environments, as well as vertebrate and invertebrate trace fossils. The analyzed data were focused on arid to semi‐arid environments recorded from Permian to Pleistocene deposits. As a result, the distribution of tetrapod footprints and invertebrate trace fossils does not seem to be controlled by the same paleoenvironmental factors. While local environmental parameters are involved in the distribution of invertebrate trace fossils, the distribution of tetrapod trace fossils in terrestrial environments seems to be more related to key environmental regional‐scale parameters, such as climate and resource availability.


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DESMOND WILLIAM KRUMMECK1

Large Burrows and Paleoenvironmental Reconstructions of the Early Triassic Katberg

Formation, South Eastern Main Karoo Basin, South Africa

1University of Cape Town, Department of Geological Sciences, 13 University Avenue, Upper Campus, University of Cape Town, Rondebosch, 7700, South Africa E‐mail: [email protected] Type of Presentation: Talk The Karoo Supergroup was deposited in the Karoo Basin from ~302 Ma to ~183 Ma (Bangert et al., 1999; Duncan and Marsh, 2006). Sedimentation commenced with the glacio‐marine tillites of the Dwyka Group, which is overlain by the marine and marginal marine Ecca Group, the Beaufort Group fluvial systems and later more arid conditions characterize the Stromberg Group. The depositional system is terminated by the igneous Drakensberg Group (Lock, 1978; Tankard et al., 1982; Smith, 1990; Cole., 1992; Catuneanu et al., 1998). This study focuses on deposits of the early Triassic Katberg Formation (Lystrosaurus Assemblage Zone) of the Beaufort Group, which records the period when life recovered from the Permian‐Triassic extinction (Broom, 1909 and Kitching, 1970 in Tankard et al., 1982; Smith and Ward, 2001; Rubidge, 2005; Botha and Smith, 2007). The scope of this research project includes: (1) identification of the burrowing animals that produced relatively large‐scale burrows (horizontal diameter 9.5 to 15 cm) in the Katberg Formation; (2) the processes that resulted in the coeval formation of a bone‐bed; and (3) the environmental messages associated with the burrows, the bone‐beds and their host rocks. A multidisciplinary approach has been used, including ichnological, sedimentological, petrographical, stratigraphical, taphonomic and paleontological observations both in the field and laboratory.


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KANTIMATI G. KULKARNI1 AND VIDYADHAR D. BORKAR1

Diplocraterion Torell from a Lower Cretaceous Prograding Delta Sequence, Kachchh, India

1Agharkar Research Institute, Geology and Palaeontology Group, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004, Maharashtra, INDIA E‐mail: [email protected] Type of Presentation: Talk The marine Jurassic sedimentary sequence in the Kachchh pericratonic rift basin, Bathonian to Valanginian in age, is overlain by about 400 m thick, non‐marine Bhuj formation (Wealden). It occupies an area of nearly 200 m2 and is represented by coarse‐grained, ferruginous, cross‐bedded sandstone, with interbeds of mudstone as well as argillaceous and carbonaceous shales. The rocks are generally unfossiliferous but for some plant fossil‐bearing horizons and heavily bioturbated beds. The bioturbation, which is of particular interest, was studied in three sections; and our observations are related to Diplocraterion‐rich horizons from three localities: Gamdau, the easternmost; Khari Nadi, a section north of Bhuj City; and near Dahisara on the Bhuj–Mandvi road being the westernmost. The horizon in the easternmost section is chronologically the oldest while the westernmost is the youngest. The bioturbation in such beds consists of monogeneric ichnofauna, overlying and underlying beds being barren or sparse in traces. These beds represent colonization windows, in turn linked to changes in hydrodynamic regime. While the monogeneric ichnocoenoses suggest opportunistic taxa (r–selected) typical of inhospitable conditions to most life forms. Such assemblages characteristically reflect brackish conditions, where salinity fluctuations are inherent. These observations when viewed vis‐à‐vis prevailing sedimentary structures, changing hydrodynamic conditions, preservation of petrified wood and foliage, occurrence of coaly streaks and stringers, accompanied by stark absence of animal remains connote a transitional environment such as is prevalent in a deltaic set‐up, particularly a proximal delta to mouth bar with intermittent tidal influence. Occurrence of this ecological setup in the sections younging in a southwesterly direction strongly supports deposition in a prograding deltaic system.


55

VERONIKA KUSHLINA1 AND ANDREI DRONOV2

First Record of Protichnites in the Lower Cambrian of St. Petersburg Region, NW Russia

1Boryssiak Paleontological Institute of Russian Academy of Sciences, Profsouznaya ul. 123, 117997, Moscow, Russia 2Geological Institute of Russian Academy of Sciences, Pyzhevsky per.7, 119017, Moscow, Russia E‐mail: [email protected] Type of Presentation: Poster Fragment of an individual trackway of Protichnites (Owen, 1852) have been found on the lower bedding surface of sandstone slab in a loose material at the base of the natural outcrop of the Lower Cambrian Tiskre Formation on the right bank of the Narva River on the border between Russia and Estonia. The trackway is straight, 3cm wide with exposed length of 12 cm. It consists of two rows of poorly defined appendage marks and a central drag between them. The trackway resemble those produced in dry sand and may represent surface tracks buried rapidly following production. General morphology of the trackway indicates that the track makers most probably were large homopodous arthropods. The Tiskre Formation consists of light‐colored massive or thick bedded, sometimes cross‐stratified quartz sandstones with thin interbeds of greenish‐grey argillaceous rocks. Conglomerate lenses are locally present. Bedding is mostly lenticular; mud cracks and ripple marks are common features. The depositional environment was interpreted as a marginal‐marine shallow‐water intertidal and/or supratidal settings with a clear evidence for subaerial exposures. Tiskre Formation contains rare fragments of trilobites, brachiopods and acritarchs indicative for the Lower Cambrian Dominopol’ Regional Stage. The Protichnites from Tiskre Formation represents probably one of the oldest evidences of some of the first life on land and the one from an extremely high latitude palaeogeographical setting.


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ABDELOUAHED LAGNAOUI1,2, SEBASTIAN VOIGT2, HENDRIK KLEIN3, HAFID SABER1, JÖRG W. SCHNEIDER2 AND ABDELKBIR HMINNA

1

Late Paleozoic ‐ Early Mesozoic Tetrapod Ichnoassemblages from Morocco: Results and Perspectives

1Laboratory of Geodynamic and Variscan Geosciences, Department of Geology, Chouaïb Doukkali University, B.P. 20, 24000 El Jadida, Morocco 2Geological Institute, Technische Universität Bergakademie Freiberg, Bernhard‐von‐Cotta‐Strasse 2, 09596 Freiberg, Germany 3Saurierwelt Paläontologisches Museum, Alte Richt 7, D‐92318 Neumarkt, Germany E‐mail: [email protected] Type of Presentation: Poster Morocco is an increasingly important place for the understanding of the evolution of early terrestrial vertebrates, mainly due to recent discoveries of abundant and diverse tetrapod footprint assemblages. New findings have been described from five stratigraphic intervals in four locales. (1) Late Carboniferous‐Early Permian deposits of the Khénifra and Tiddas basins provided tracks of Batrachichnus, Limnopus, Amphisauropus, Ichniotherium, Dimetropus, Varanopus‐Hyloidichnus and Dromopus. (2) Middle‐Late Permian red beds of the Argana Basin yielded footprints of Amphisauropus, Pachypes, Erpetopus, Hyloidichnus and Dromopus. (3) Assemblages with Rhynchosauroides, Protochirotherium and Synaptichnium indicate the presence of Early Triassic deposits in the Argana Basin. (4) Middle Triassic strata of the same area contain tracks of Procolophonichnium, Rhynchosauroides, Synaptichnium, Isochirotherium, Chirotherium, Rotodactylus and Atreipus–Grallator, apart from complex tetrapod burrows as the oldest record of communal fossorial behaviour in palaeotropical vertebrates. (5) Late Triassic deposits yielded tracks of Rhynchosauroides, Apatopus, Synaptichnium, Parachirotherium, Atreipus–Grallator and Eubrontes (Argana Basin) as well as Brachychirotherium (Sidi Said Maachou Basin). Our data extend the stratigraphic and geographic range of several important groups of early terrestrial tetrapods, besides linking certain Paleozoic‐Mesozoic tetrapod ichnofaunas of Europe, Gondwana and North America. Exploration in other Moroccan areas is intended to refine the ichnofossil record.


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MARY LEAMAN1 AND DUNCAN MCILROY1

Three Dimensional Morphology of Diplocraterion

1MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Talk Three dimensional mini‐permeametry of a Diplocraterion ichnofabric will increase our understanding of its bioturbation effects in a conventional siliciclastic petroleum reservoir. Diplocraterion isp. is a very recognizable trace fossil owing to the U‐shaped burrow with spreite between the tubes. The purpose of this project is to (1) model the morphological features of Diplocraterion in three dimensions to gain a better understanding of its burrowing behaviour, and (2) to understand Diplocraterions effect on permeability. Diplocraterion samples were collected from the Scarborough Formation (Middle Jurassic), Cloughton Wyke, UK with the intent of studying the distribution of permeability and morphology using serial grinding and mini‐permeametry techniques. This will be the first documented attempt at combining these techniques which will lead to understanding the trace fossil in three dimensions. Permeability values of the whole rock range between a minimum of 11 and a maximum of 395 mD. Higher than expected values were observed in and around the Diplocraterion tubes. Many characteristic morphological features of Diplocraterion were observed (funnels, tubes, spreite), plus a few previously undescribed features, which correspond to new insight on the behaviour of Diplocraterion.


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SPENCER G. LUCAS1 AND HENDRIK KLEIN2

Triassic Time and Tetrapod‐Body‐Fossil and Footprint Biostratigraphy and Biochronology

1New Mexico Museum of Natural History and Science, 1801 Mountain Rd. NW, Albuquerque, NM 87104‐1375 2Saurierwelt Paläontologisches Museum, Alte Richt 7, D‐92318 Neumarkt, Germany E‐mail: [email protected] Type of Presentation: Poster The global biostratigraphic distribution of Triassic tetrapod body fossils is the basis of a tetrapod biochronology that divides Triassic time into eight land‐vertebrate faunachrons (LVFs). The Triassic LVFs have boundaries defined by the first appearance datums (FADs) of tetrapod genera or species: Lootsbergian, Nonesian, Perovkan, Berdyankian, Otischalkian, Adamanian, Revueltian and Apachean. The global distribution of Triassic tetrapod footprints allows five footprint‐based biochrons to be recognized: (1) dicynodont tracks (Lootsbergian); (2) Protochirotherium biochron (Nonesian); (3) Chirotherium barthii biochron (Nonesian‐Perovkan); (4) Atreipus‐Grallator biochron (Perovkan‐Berdyankian); and (5) Brachychirotherium biochron (Otischalkian‐Apachean). Compared to the tetrapod body fossil record, the footprint‐based biochrons provide less temporal resolution as ichnogenera and ichnospecies at best reflect families or higher biotaxonomic units, which have slower evolutionary turnover rates than the genera and species used to delineate the body‐fossil‐based biochronology. The Triassic tetrapod body fossil and footprint records strongly overlap and the time intervals they discriminate are generally similar. Together, the tetrapod body fossil and footprint records resolve Triassic time about as well as do the Triassic stages. The path forward in developing a more precise Triassic tetrapod biochronology is in placing tetrapod body and footprint fossils into stratigraphy and in basing their alpha taxonomy on the sound principles of evolutionary taxonomy.


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ALEXANDER G. LIU1, DUNCAN MCILROY2 AND MARTIN D. BRASIER3

Metazoan locomotion at ~565 Ma: Detailed analysis of surface traces from the late Ediacaran

Mistaken Point Formation, Newfoundland

1University of Cambridge, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK 2Memorial University of Newfoundland, Department of Earth Sciences, Memorial University of Newfoundland, 300 Prince Philip Drive, St. John’s, NL, A1B 3X5, Canada 3University of Oxford, Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK [email protected] Type of Presentation: Talk The biological affinities of the enigmatic Ediacaran biota, known from multiple fossil assemblages around the world, remain largely unresolved for the oldest members of the group, those of the Avalon region (Newfoundland and the UK). Evidence for behaviour in Avalonian assemblages is thus significant, since it may provide important constraints upon the timing and nature of metazoan evolution. In 2010, we described an assemblage of centimetre‐scale, bedding‐parallel, near surface traces from a bedding plane in the deep marine Mistaken Point Formation, Newfoundland. These fossils, known only from one surface, show sedimentary “levees” and curved internal siltstone ridges that are concave in the inferred direction of movement, with some ending in circular depressed pits. The impressions are interpreted to have originated from the actions of muscular metazoan organisms, moving in a similar fashion to modern actinian cnidarians (Liu et al., 2010). Here the assemblage is discussed in detail, with morphological and statistical data for all 72 candidate traces presented. The structures are discussed with respect to alternative non‐ichnological hypotheses, none of which satisfactorily account for all of the observed features. We therefore consider that, on the basis of the expanded dataset, these impressions are most parsimoniously interpreted as locomotory traces produced close to the sediment‐water interface and thus record the earliest currently‐known evidence for metazoan locomotory activity in the fossil record. Consideration of similar traces in shallow‐marine Ediacaran units from Newfoundland and recent claims for ichnological activity in other global Ediacaran localities, appear to suggest that locomotory activity began in the late Ediacaran Period, ~565 Ma. Ichnofossils then increased in size, abundance and complexity through to the Ediacaran‐Cambrian boundary, when pervasive vertical bioturbation became commonplace in sedimentary successions worldwide.


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M. GABRIELA MÁNGANO1, RICHARD G. BROMLEY

2, DAVID A.T. HARPER3, ARNE T. NIELSEN2, M. PAUL SMITH

4

AND JAKOB VINTHER5

Non‐biomineralized Carapaces, Trace Fossils and the Lower Cambrian Sea‐floor Landscape: An

Example from the Sirius Passet Lagerstätte of Greenland 1Department of Geological Sciences, University of Saskatchewan, 114 Science Place Saskatoon, SKS7N 5E2. Canada 2Natural History Museum of Denmark (Geological Museum), University of Copenhagen, ØsterVoldgade 5‐7, DK‐1350 Copenhagen K, Denmark 3Department of Earth Sciences, Durham University, Durham DH1 3LE, UK 4Oxford UniversityMuseum of Natural History, Parks Road, Oxford OX1 3PW, UK 5Jackson School of Geosciences, The University of Texas at Austin, 1 University Station, C1160 Austin, Texas 78712‐0254, USA E‐mail: [email protected] Type of Presentation: Talk Trace fossils in direct association with non‐biomineralized carapaces are known from a large number of Burgess Shale‐type Cambrian fossil lagerstätten. Almost all of these reports, however, involve relatively simple structures. Simple trails and burrows, such as Helminthoidichnites, Helminthopsis, Gordia and Planolites, are by far the most common ichnotaxa reported. Although at first inspection, the lower Cambrian Sirius Passet ichnofauna of Greenland seems to fit within this general characterization, the complexity and disparity of structures associated with large non‐biomineralized, Tegopelte‐like carapaces represent a clear departure. Trails, interconnected burrow systems, narrow‐caliber, filament‐like structures with dendritic terminations, and massively in‐filled and annulated burrows occur within the perimeter of non‐mineralized carapaces. Taphonomic controls were partially responsible for the distinct association of these structures and carapaces, but ecologic conditions are also thought to have played a significant role. Annulated structures may be related to scavenging and/or deposit feeding. Interconnected burrow systems provide evidence for re‐use of structures, suggesting grazing on or farming of bacteria. Carapaces may have created a sharp boundary, further decreasing oxygen diffusion into the sediment and promoting the growth of sulfur bacteria that served as the primary food for small macrofauna and meiofauna. Similar to modern sunken whale carcasses that export organics to the ocean floor and create an “oasis” of faunal diversity in a seemingly featureless landscape, the Cambrian non‐biomineralized carapaces may have acted as attractors, supporting a community of small benthic invertebrates. Carcasses and molds created a patchy distribution of food resources, increasing heterogeneity in an otherwise mostly homogenous Cambrian landscape of microbial mats.


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ANTHONY J. MARTIN1

Toward One Neoichnology: The Georgia Barrier Islands as Exemplars for Integrated Study of

Modern Continental and Marine Traces and Ichnoassemblages

1Department of Environmental Studies, Emory University, Atlanta, Georgia 30322 USA E‐mail: [email protected] Type of Presentation: Talk Neoichnology as a formal science has enjoyed a long history, starting with studies by William Buckland, Charles Darwin and others in the 19th century and is thriving today internationally. Yet neoichnologists still face challenges in reconciling divisions between continental and marine neoichnology. For one, neoichnologists rarely study both continental and marine traces and tracemakers, an understandable schism that may be a function of geographic bias. Secondly, marine and continental traces are rarely described together in the same study. Where these two fields can come together, though, is on barrier islands, where continental and marine‐related ichnoassemblages are side‐by‐side in spatially limited areas. In this study, I propose the Georgia barrier islands as a starting place for integrating these neoichnological realms. The Georgia barrier islands have the following advantages for facilitating holistic approaches in neoichnology: (1) a temperate‐subtropical setting, resulting in much biological activity (trace‐making); (2) diverse plant, invertebrate and vertebrate tracemakers, all close to one another; (3) a variety of substrates; and (4) trace fossils in Late Pleistocene strata and sub‐fossil firmgrounds (e.g. relict fresh‐water and salt‐water marsh deposits) on and near most islands, which can be compared to modern traces. From an ichnofacies perspective, the Georgia barrier islands and offshore environments provide incipient ichnocoenoses for the Celliforma, Coprinisphaera, Mermia, Scoyenia, Psilonichnus, Skolithos, Cruziana, Glossifungites, Trypanites and Teredolites ichnofacies. Laterally abrupt transitions between these ichnocoenoses also can serve as predictive models for vertical shifts in ichnoassemblages and ichnofabrics associated with sea‐level fluctuations. Paired modern‐ancient analogues of traces, in which modern examples are all from the Georgia barrier islands, will be shown as examples for their applicability to palaeoichnology.


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NICHOLAS J. MINTER1, M. GABRIELA MÁNGANO

1 AND JEAN‐BERNARD CARON2

Skimming the Surface with Burgess Shale Arthropod Locomotion

1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, S7N 5E2, Canada 2Dept. Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, ON, M5S 2C6, Canada E‐mail: [email protected] Type of Presentation: Talk Despite being discovered over 100 years ago, the Middle Cambrian Burgess Shale Formation of Canada continues to yield important new insights into the evolution and ecology of animals during the Cambrian explosion. Burgess Shale body fossils, with their exceptional soft‐tissue preservation, have traditionally been used to infer the palaeoecology of a number of species; however, direct evidence of animal behaviour, in the form of trace fossils, is a largely elusive component of the biota. Here we report the first arthropod trackways from the Burgess Shale Formation. Trackway dimensions and the requisite number of limbs are matched with the body plan of a tegopeltid. Tegopelte is over twice the size of all other known benthic Burgess Shale arthropods and is considered to have been a predator or scavenger. Trackway analysis demonstrates the producers were capable of very high‐geared gaits, rapidly skimming across the seafloor with short propulsive backstroke phases and metachronal waves of eight limbs moving along the body. Re‐examination of body fossils has also identified the presence of gut diverticulae, confirming a carnivorous mode of life. The trackways occur in the oldest part (Kicking Horse Shale Member) of the Burgess Shale Formation, which is also known for its scarce assemblage of soft‐bodied organisms, and indicate at least intermittently oxygenated bottom waters and low sedimentation rates. Integrated trace and body fossil evidence therefore supports previous hypotheses on the locomotory capabilities and mode of life of such arthropods and provides insights into the palaeoecology and palaeoenvironments of the Burgess Shale biota.


63

PETE MISKELL1, RICH CALLOW2, AND DUNCAN MCILROY3

Paleoenvironmental Investigation of a Possible Late Cretaceous Anoxic Event from the

Rosario Formation, Baja California, Mexico 1New Resource Plays, Oil Sands, Cenovus Energy Inc., Calgary, Alberta. T2P 0M5. Canada 2Department of Geology and Petroleum Geology, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, United Kingdom 3MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Poster

The Rosario Formation of Baja California, Mexico, is a Late Cretaceous succession of shallow marine to deep marine slope and basin deposits. Deep marine depositional facies include sub‐marine canyon fill, channel‐levee complexes, and overbank deposits. The succession consists of hemipelagic and gravity‐current sediments that include turbidites, mass transport deposits, slumps, and debris flows, ranging in size from very fine‐grained mudstones and siltstones to cobble‐boulder conglomerates. Most of the fine‐grained sediments of the Rosario Formation are highly bioturbated with a variety of ichnotaxa such as Phycosiphon, Nereites, Palaeophycus, and Scolicia.

The Cajiloa channel system from the Late Cretaceous, Upper Member of the Rosario Formation shows an unusual sharp, non‐erosional change from the deposition of bioturbated blue‐grey sandstones and siltstones to the deposition of unbioturbated black mudstones with thin inter‐bedded layers of volcanic tuffs. This facies shift is anomalous to the Upper Member of the Rosario Formation of Baja California, Mexico, and indicates a significant event.

This study has investigated the abrupt sedimentological, ichnological, and geochemical changes associated with this event through use of ichnological analysis, petrography, x‐ray diffraction (XRD), inductively coupled mass spectrometry (ICP‐MS), total organic carbon (TOC), and carbon isotopic analysis (δ13Corg). X‐ray diffraction suggests that the black mudstones are derived from the alteration of volcanic ash to montmorillonite. TOC and δ13Corg analyses show a negative isotopic excursion and a decrease in organic carbon with the onset of the paleoenvironmental event.

The data suggests that the facies shift from bioturbated sandstones and siltstones to unbioturbated black mudstones with inter‐bedded layers of water‐lain tuff occurred as a result of Late Cretaceous volcanism. Volcanic ash supplied macro‐ and micro‐nutrients to surface waters which stimulated and supported a productivity bloom that ultimately increased the flux of carbon to the sea floor. The high sedimentation rates associated with the volcanic activity diluted the amount of organic carbon. It should not be assumed that the absence of


64

bioturbation is due to anoxic conditions. These sediments were deposited on an active slope system where turbidity flows would have mixed the water column and supplied dissolved oxygen to bottom waters. The absence of bioturbation is suggested to be the result of the high sedimentation rates associated with active volcanism. The continuous and high rates of sediment deposition did not permit colonization of the sea floor. This event is therefore described as a Volcanically Induced Productivity Event (VIPE).


65

MASAKAZU NARA1

Palaeoecology of a Pleistocene Ocean Current‐Generated Sandridge Complex: Benthic Life

Under the Kuroshio Current

1Faculty of Science, Kochi University, 2‐5‐1 Akebono‐cho, Kochi, 780‐8520, Japan E‐mail: nara@kochi‐u.ac.jp Type of Presentation: Talk A shelf sand ridge complex of the Pleistocene Ichijiku Formation crops out in the Boso Peninsula, Japan. The deposits, up to 400 m thick, consist mainly of coarse‐grained sands with large‐scale trough cross‐stratification. Thinly cross‐stratified sandy gravels and thin beds of mud also occur in some intervals. The sand ridge complex is interpreted to have developed on a transgressive shelf and formed by a branch of the (palaeo‐) Kuroshio Current, which ran through a narrow strait. Sedimentological and ichnological studies were made to reconstruct the dynamic benthic life in the sand ridge system. The trough‐cross stratified sands are interpreted as large‐scale dune deposits. They contain such trace fossils as Bichordites monastiriensis, Macaronichnus isp., ?Sakoites isp., escape structures, Piscichnus waitemata and Scolicia isp. Rosselia socialis is very rarely seen. The former three structures occur in foresets of the dunes. Considering the formative mechanism of the foreset laminae, these trace fossils are interpreted to have adapted to highly shifting sands. The zones of abundant burrows are often situated just below reactivation surfaces. This is probably reflected by cessation of dune migration. On the other hand, the others burrowed only from top of the cross‐stratified set. This suggests producers of such trace fossils lived on or just below the stoss‐side floor, where current speed was relatively weak and substrates were more stable than those of the foresets. The sandy gravels are interpreted as sand ribbon deposits and rarely contain such trace fossils as Piscichnus waitemata and Skolithos linearis. Strong currents and shifting substrate might prohibit colonization of other tracemakers. The massive muds of probable fluid mud origin yield no trace fossils. The durations of mud deposition were probably too short to allow any colonization, and/or the “exotic” fluid mud might prohibit any immigration from the surrounding sandy habitats.


66

MASAKAZU NARA1 AND LUDVIG LÖWEMARK

2

Ichnology of Neogene Wave‐Dominated Shallow Marine Settings: Examples from the Lower

Miocene Yehliu Sandstone Member in Northern Taiwan

1Faculty of Science, Kochi University, 2‐5‐1 Akebono‐cho, Kochi, 780‐8520, Japan 2Alfred Wegener Institute for Polar and Marine research, Bussestraße 24, 27570 Bremerhaven, Germany E‐mail: nara@kochi‐u.ac.jp Type of Presentation: Poster Previous ichnological studies concerning wave‐dominated shallow marine settings have been based mostly on Palaeozoic and Mesozoic strata. Taking biotic evolution into account, ichnofabrics likely also have changed through time. We therefore made a case study of Neogene ichnology of a late Early Miocene wave‐dominated shallow marine siliciclastic succession of the Yehliu Sandstone Member, Taliao Formation, which was deposited in the palaeo‐Asian continental margin. The member consists of an overall coarsening‐up facies succession. Massive muddy sandstones at the base of the observed section grade upward into well‐sorted medium‐grained sandstones, partially showing cross stratification, that are finally covered with parallel‐laminated medium‐grained sandstones. This overall succession represents offshore transition to foreshore sediments of a typical strand‐plain system. The most prominent biogenic structure of the muddy sandstones (offshore‐transition deposit) is indistinct bioturbation. The sandstones also contain many discrete trace fossils, like Bichordites isp., Piscichnus waitemata, Piscichnus isp. and Schaubcylindrichnus coronus. Infill of P. waitemata and Piscichnus isp. occasionally contain reworked and fragmented linings of S. coronus and is sometimes re‐burrowed by Phycosiphon incertum. Although the well‐sorted medium‐grained sandstones of shoreface origin contain fewer biogenic structures compared with the offshore‐transition sediment, massive or mottled appearance due to bioturbation is also common in this interval. Discrete trace fossils are Ophiomorpha isp., Bichordites isp. and S. coronus. Body fossils of crypeasteroids also occur as storm lags. The topmost parallel‐laminated sandstones are probably foreshore and backshore deposits. The former is characterised by abundant occurrence of Macaronichnus segregatis, while the latter contains no visible ichnofabric.


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C. NETO DE CARVALHO1,2, JESUS SALAZAR CABRERA3 AND ROIGAR LÓPEZ RIVAS3

New Findings in the “Lost World”: the Significance of Microbial Mat Related Structures and Skolithos Piperock in the Sand Flat Sequences of Roroimü Tepuy (post‐Roraima Group,

Venezuela)

1Geopark Naturtejo da Meseta Meridional – European and Global Geopark, Geology and Paleontology Office, Centro Cultural Raiano, Av. Joaquim Morão, 6060‐101 Idanha‐a‐Nova, Portugal 2Municipality of Idanha‐a‐Nova, Av. Joaquim Morão, 6060‐101 Idanha‐a‐Nova, Portugal 3Fundación Geoparques de Venezuela. Urbanizacion la Esmeralda, calle El Angel, residencias Carabalí, piso 9 apartamento 91 B, 1083 Baruta‐Miranda, Venezuela E‐mail: [email protected] Type of Presentation: Poster Roroimü Tepuy corresponds to the uppermost part of the Roraima Group and to post‐Roraima sandstones. 500 m‐high scarps exposes the top of Uaimapué Fm. gently dipping to NNE, and the complete flat‐lying sequence of Matauí Fm., composed by 3 sedimentary facies in a regressive sequence: sand flat (infratidal to upper intertidal subfacies), eolian and braided‐streaming (deltaic). An erosive unconformity separates both formations. The minimum age for the Avanavero magmatism within Uaimapué Fm. was found to be Mesoproterozoic thus leaving a hiatus between this and Matauí Fm. of hundreds of millions of years as this sandstone sequence is unaffected by the Sunsás (Grenvillian) Orogeny. Microbially induced sedimentary structures atop bedding planes include ripple patches resulting from tide‐controlled waves and currents, endobenthic multidirectional or palimpsest ripples, leveled depositional surfaces and wrinkle structures, microbial sand chips, erosional remnants and pockets, cracked and flat‐topped ripple crests, shrinkage cracks and elephant skin. Also of utmost interest is the discovery of typical Phanerozoic Skolithos. The oldest traces of deep bioturbation have been recovered from the middle part of the Nemakit‐Daldynian. Skolithos is among the Late Precambrian trace fossils. However Skolithos piperock ichnofabric is considered by many as indicative of an Early Cambrian (latest Tommotian‐Atdabanian) or younger age. In Venezuela the Lower Palaeozoic sequence lies discordantly over the Precambrian basement of the Guayana Craton. The onset of vertical bioturbation in Roroimü Tepuy certainly represents one of the earliest developments of mixground in what is still a matground‐dominated world.


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C. NETO DE CARVALHO1,2, ANDREA BAUCON3, AND SARA CANILHO3

Beaconites‐Taenidium‐Scoyenia Association from the Alluvial Fan Deposits of Sarzedas Basin

(Portugal)

1Geopark Naturtejo da Meseta Meridional – European and Global Geopark, Geology and Paleontology Office, Centro Cultural Raiano, Av. Joaquim Morão, 6060‐101 Idanha‐a‐Nova, Portugal 2Municipality of Idanha‐a‐Nova, Av. Joaquim Morão, 6060‐101 Idanha‐a‐Nova, Portugal 3 Università di Milano, Dipartimento di Scienze della Terra 20133‐Milano, Italy E‐mail: [email protected] Type of Presentation: Poster Trace fossils from alluvial fan deposits were only rarely described. Here we document an association of meniscate backfilled burrows in the alluvial cone of Sarzedas in direct relation between the Rapoula fault scarp and the flooding plain. Sarzedas Basin is a ramp valley‐type of basin related with the uplifting of the Iberian Central Cordillera filed with 150 m of episodic alluvial fan‐ to predominantly endorreic braided river‐related sediments as response to major tectono‐climate events. The sequence is composed by two groups: the Beira Baixa Group dated from Eocene‐lower Tortonian composed by badly‐sorted feldspatic sandstones and pedogenic carbonates, and the upper Miocene‐to‐Pliocene Murracha Group constituted basically by sequences of quartzite breccias and conglomerates. Torre Formation is the lower unit of the Murracha Group which was dated from the upper Tortonian‐Messinian. It is formed by syn‐tectonic debris flow and sheet flow facies passing distally to micaceous sandstones and lutites in the base of the alluvial fan. A quarry in the alluvial fan of Sarzedas shows very fine‐grained greenish siltstone subjected to edaphic processes with dense full‐relief Beaconites coronus‐Taenidium‐Scoyenia ichnofabrics in the last 8 m. These ichnofabrics are related with occupation of the ephemeral well‐drained soil by arthropods (insect‐larvae or millipedes) under semiarid conditions, where abundant vertical elements, with striated burrow lining, document escape structures related with progressive desiccation.


69

RENATA G. NETTO1, JORDI M. DE GIBERT

2, ZAIN BELAÚSTEGUI2, H. ALLEN CURRAN3

AND FRANCISCO M. W. TOGNOLI1

Ophiomorpha nodosa from Southern Atlantic Pleistocene Deposits with Comparison to

Modern Callianassid Burrows of the Southernmost Coast of Brazil

1Universidade do Vale do Rio dos Sinos, Programa de Pós‐graduação em Geologia, Av. Unisinos, 950¸ 93022‐000 São Leopoldo RS, Brazil 2Universitat de Barcelona, Facultat de Geologia, C/Martí i Franqués, s/n, 08028 Barcelona, Spain 3Smith College, Department of Geology, Clark Science Center, 44 College Lane, Northampton, Massachusetts, 01063, U.S.A. E‐mail: [email protected] Type of Presentation: Talk Ophiomorpha is the most conspicuous trace fossil in Pleistocene deposits of the Southern Atlantic coast in Brazil. In the Chuí Formation of Rio Grande do Sul, this ichnogenus is widespread and shows remarkable morphological features. Burrow systems are composed of vertical shafts and horizontal tunnels (Ø=2‐5 cm), which bifurcate to form extensive networks of both irregular and regular mazes and boxworks. Cul‐de‐sac chambers can be locally observed, with occasional, non‐pelleted, thick‐lined shafts emerging from them. The lining of the galleries is thick (Ø=0.5‐3.5 cm), internally smooth but externally knobby and constituted of ovoid to irregular silty‐sandy pellets 1 to 3 cm long. Ovoid pellets are tripartite, as if formed by the amalgamation of three rounded pellets. The pellets occur side‐by‐side, without a preferential orientation in the shafts, but also arranged as in a brick wall at the roof of horizontal tunnels. Irregular pellets are massive, trapezoidal to triangular in shape and located in the floors of horizontal burrows, with the acute end facing outwards. These burrows have been assigned to O. nodosa, but some characteristics of the pellet morphology and arrangement in the burrow lining have never been described for this ichnospecies. Similar pellet features have been observed in modern burrows of Sergio mirim (formerly Callianassa mirim), the unique species of ghost shrimp that inhabits the southernmost beaches of Brazil. Loose, ovoid pellets (Ø=1‐1.5 cm) were recovered by pumping up to 1 m depth in parts of the intertidal zone where shaft openings were visible, while burrow fragments lined by irregular, mostly trapezoidal pellets, 2 to 3 cm long were obtained below this depth. The morphological similarities with the Ophiomorpha from Chuí and the record of S. mirim carapaces in Pleistocene rocks points to this species as the most likely Ophiomorpha tracemaker in southernmost Brazil since at least the Pleistocene.


70

AMRUTA R. PARANJAPE1, KANTIMATI G. KULKARNI1 AND SHWETA S. GURAV1

Implications of Gastrochaenolites‐Bearing Conglomerate at the Base of Bada Bagh Member,

Jaisalmer Formation, Rajasthan, India

1Geology and Palaeontology Group, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004, INDIA E‐mail: [email protected] Type of Presentation: Talk The Jaisalmer Formation heralds the Mesozoic marine transgression in the Western Rajasthan Shelf. The formation consists of five members – Hamira, Joyan, Fort, Bada Bagh and Kuldhar – and is believed to represent a single depositional event. It is Callovian‐Oxfordian in age and comprises dominantly calcareous rocks. The present study highlights the occurrence of an intra‐formational, intra‐basinal conglomerate bed at the base of Bada Bagh Member. This conglomerate is characterised by Gastrochaenolites‐bearing clasts of dolomitised limestone in a coarse sandy ferruginous matrix. Most of the Gastrochaenolites show preservation of the main chamber; the necks having been eroded. The clasts derived from older Fort Member rocks show crude imbrication. Development of Gastrochaenolites is suggestive of a hard substrate, minimal sedimentation and shallow water conditions. The clasts are sub‐rounded and extensively bored from all directions. The Gastrochaenolites borings facilitated the erosion of this limestone bed and constant rolling of clasts by waves provided newer surfaces to the boring organisms. The conglomerate largely fines upwards. However, it exhibits coarse cross beds with intermittent sandy layers. These sandy layers show presence of infaunal traces viz. Gyrochorte, Phycodes and Planolites. This indicates that the conglomerate was deposited in the photic zone with abundant availability of detrital food. Although an in situ hardground was not located, its presence can be conjectured by the occurrence Gastrochaenolites‐bearing clasts. Absence of the neck suggests subsequent erosion of the hardground and transportation of the clasts. Thus, the base of this conglomerate possibly represents a wave‐ravinement surface. This indicates a depositional hiatus at the base of Bada Bagh Member suggesting more than one depositional event constitutes the Jaisalmer Formation.


71

V.S. PARIHAR1 AND V. GAUR1

Trace Fossil Assemblages in the Pokaran Sandstone of Marwar Supergroup, Pokaran Area,

District ‐ Jaisalmer, Western Rajasthan, India

1Geology Department, New Campus, Jai Narain Vyas University, Jodhpur ‐ 342005, Rajasthan, India E‐mail: [email protected] Type of Presentation: Poster Well preserved Thalassinoides isp., Ophiomorpha isp., Planolites isp. and Psilonichnus isp., trace fossils are reported from Pokaran Sandstone of the Jodhpur Group, the lower succession of the Marwar Supergroup. The Marwar Supergroup is a 1000m thick lithostratigraphic unit that occupies a large area in north western Rajasthan and unconformably overlies the 779‐681 Ma old Malani Igneous Suite. It is subdivided into three groups: the lower Jodhpur Group; middle Bilara Group and upper Nagaur Group, the Jodhpur and Nagaur groups are arenaceous and argillaceous sequences, whilst the Bilara Group is a calcareous sequence. The Pokaran Sandstone unconformably overlies the Pokaran boulder bed, which is the basal lithofacies of the Late Neoproterozoic‐Early Cambrian Marwar Suergroup. The Pokaran boulder bed occurs in three distinct forms viz., massive conglomerate, boulder spread and stratified conglomerate. These three forms of boulder bed independently rest over the basement of the Malani Rhyolite. The Pokaran Sandstone is sub‐divided into two lithofacies: a red to maroon shally sandstone, and a reddish brown fine to medium grained sandstone. The trace fossils are preserved in full relief in light brown to reddish brown fine to medium grained sandstone in the Pokaran area which is 180 kms northwest of Jodhpur. They are identified as Thalassinoides suevicus, Ophiomorpha isp. (produced by decapod crustaceans), Planolites isp. (produced by worm‐like animals), and Psilonichnus isp. (produced by arthropods). The ichnogenera Thalassinoides, Ophiomorpha and Planolites infer a shallow marine depositional environment and Psilonichnus allows characterization of a marsh environment. No age can be assigned on the basis of these trace fossils as they range from Cambrian to Recent.


72

V. S. PARIHAR1, V. GAUR1 AND S.L. NAMA1

Trace Fossils and Microbial Mat‐Induced Sedimentary Structures from the Girbhakar

Sandstone of Marwar Supergroup, Bhopalgarh Area, Jodhpur, Rajasthan, India

1Department of Geology, Faculty of Science, J.N.V. University, Jodhpur ‐ 342005 (Raj.)., India E‐mail: [email protected] Type of Presentation: Poster Well‐preserved trace fossils (Thalassinoides isp., Planolites isp. and Palaeophycus isp.) and microbial mat‐induced sedimentary structures are reported from the Girbhakar Sandstone, the upper sequence of the Jodhpur Group of the Marwar Supergroup. The Marwar Supergroup is a 1000m thick lithostratigraphic unit, which occupies a large area in north western Rajasthan and unconformably overlies the c. 779‐681 Ma old Malani igneous suites. It is subdivided into three groups: the lower Jodhpur Group, middle Bilara Group and Upper Nagaur Group; the Jodhpur and Nagaur groups are arenaceous and argillaceous sequences, whilst the Bilara Group is a calcareous sequence. The trace fossils are preserved in fine grained sandstone and ferruginous sandstone, whereas mat‐induced sedimentary structures occur in patches on the top of fine grained sandstone bedding surfaces. The area under present investigations lies around Bhopalgarh, which is 70 km northeast of Jodhpur. All these ichnogenera represent marine and shallow marine depositional environments. No age can be assigned on the basis of these trace fossils as they range from Cambrian to Recent but the presence of microbial mat‐ induced sedimentary structures is of Ediacaran affinity and an Ediacaran age can be assigned to the Jodhpur Sandstone of the Bhopalgarh area, which is named the Girbhakar Sandstone Formation.


73

SATISH J. PATEL1 AND A.N.REDDY2

Ichnofossil Assemblages of a Coniacian‐Santonian Sandstone, Cauvery Basin, India

1MS University Vadodara, India Department of Geology, M.S. University, Vadodara‐390002, India 2ONGC INDIA Oil and Natural Corporation Ltd, Chennai‐ 600049, India E‐mail: [email protected] Type of Presentation: Talk The Cauvery Basin is a pericratonic basin located along the south east coast of India. It was developed as a consequence of breakup of Gondwanaland during the Late Jurassic. The Albian to Maastrichtian sediments are exposed around the Ariyalur area. The rock sequence has been divided into the Uttatur Group, Trichinopoly Group and Ariyalur Group, consisting of seven formations. The Trichinopoly Group consists of the Coniacian‐Santonian sandstone unit of Garudamangalam Formation, which unconformably overlies Karai Shale. Well preserved ichnofossils were found in Coniacian‐Santonian sandstones exposed at Kulkkallanattam stream in the Ariyalur area, Cauvery Basin. They consist of infaunal structures of both suspension and deposit feeders. Five ichnofossils are present in a fine to coarse grained sandstone which includes Ophiomorpha, Palaeophycus, Planolites, Skolithos and Thalassinoides. The study infers that ichnofossils Skolithos and Ophiomorpha represent infaunal colonization of suspension feeders in high energy conditions in a shifting substrate, whereas Thalassinoides and Planolites‐Palaeophycus ichnofossils indicate infaunal deposit feeders living at the sediment‐sediment interface in low to moderate energy conditions. Furthermore, the abundance and diversity of the trace fossils indicates there were alternating fluctuations in energy conditions, which led to the development of Skolithos and Cruziana Ichnofacies type condition during the deposition of Coniacian‐Santonian sandstones in foreshore‐shoreface environments in Cauvery Basin.


74

PABLO J. PAZOS1, DIANA E. FERNÁNDEZ1, MARCOS COMERIO1 AND GUILLERMO E. OTTONE

1

Ichnology of an Intertidal Palaeosurface:

The Record of Tidal Water Fluctuations, Palaeotopography, Microbial Mat Variability and Trace Fossil Distribution in the Lower Cretaceous of Patagonia, Argentina

1University of Buenos Aires, Instituto de Estudios Andinos "Don Pablo Groeber"(IDEAN – CONICET), Dpto. de, Ciencias Geológicas. Ciudad Universitaria, Pabellón II (1428), Buenos Aires, Argentina E‐mail: [email protected] Type of Presentation: Talk Tidal flats are complex environments influenced by tidal fluctuations, fluvial discharge and climate; the interplay of such factors affects the time of subaerial exposure, microbial mat development and preservation of trace fossils in recent and ancient records. Microtopography related to the lateral migration of a tidal channel enabled the analysis of trace fossils with physical and biologically induced sedimentary structures. In the depressed areas, tidal ebb ripples are well preserved. These contain delicate xiphosuran trackways developed on the ripple crests before the water level fell. In the ripple troughs, exquisite meandering and looping trace fossils are documented. The preservation is enhanced by microbial mats that favoured undermat miners, but precluded vertical burrowers. Water table fluctuations are evidenced in flattened ripple crests, longitudinal marks of temporary water level positions that vary laterally, indicating inclined palaeotopography. The shallow palaeotopographic areas show almost complete erosion of ripples and development of epistratal mats where slippery conditions are documented by vertebrate tracks, tentatively assigned to dinosaurs. The examination and comparison of the microbial mats under SEM, permits to conclude that these were unaltered where the invertebrate trace fossils are recorded, but they were disturbed and remobilized in the rim of the slippery tracks, confirming an epistratal nature of the biofilm but also the disruption of the mat without conclusive evidence of mat exposure. Moving laterally in the direction of the shallowest area, only deformation on the sedimentary induced structures is recognized, but organized in a perpendicular pattern of deformation, documenting complex water circulation during tidal ebb. An absence of ebb ripples and dinoflagellates in the overlying interval suggests that the trace fossils were produced most probably during the tidal flood, while reduction of the water level related to the palaeotopography took place, without any evidence of fluvial interaction on the tidal flat during the ebb part of a tidal cycle.


75

CECILIA A. PIRRONE1, LUIS A. BUATOIS2, AND RICHARD BROMLEY3

Ichnotaxobases for Bone Bioerosional Structures: A Proposal

1CCT‐Mendoza, CONICET. ICB ‐ Universidad Nacional de Cuyo, Av. Adrián Ruiz Leal s/n, Parque General San Martín, CP:5500, Mendoza, Argentina 2University of Saskatchewan, Department of Geological Sciences. University of Saskatchewan. 114 Science Place, Saskatoon, SK, S7N 5E2, Canada 3Geological Museum – SNMØster Voldgade 5‐7, DK‐1350 Copenhagen K Denmark E‐mail: cpirrone@mendoza‐conicet.gob.ar Type of Presentation: Talk Bioerosion trace fossils in bones are commonly used to infer palaeoecological conclusions. Little has been published on the methodology for naming bioerosional trace fossils in bones, including definition of adequate ichnotaxobases, although their value as direct evidence of species interactions in the fossil record is significant. We define bioerosional trace fossils in bones as biogenic structures that cut or destroy osteological tissue structures (hard substrate) as the result of mechanical and/ or chemical processes. Most traces found in biological tissue (bone) are the result of specific ecological niche selection by specialist necrophagous organisms, produced during different stages of decay, as reported in forensic studies. Although the selection of substrate reflects obligate behaviour by organisms having specific feeding requirements and that specific biological tissue (bone) is used as source for those nutrients, adopting substrate as an ichnotaxobase is controversial. We propose the following ichnotaxobases in order to assist in naming traces in bones: general morphology, bioglyphs, filling, branching, pattern of occurrence and site of emplacement. The most common general morphologies are: pits and holes, chambers, trails, tubes, channels, grooves, striae and furrows. The main types of bioglyphs are grooves and scratches, which may display different arrangements, such as parallel and opposing or arcuate and paired. Nature of the fill may help to recognize origin, composition and relationship with the surrounding sediment, as well as processes of destruction or consumption of bony tissue. The structure and layout of filling, such as meniscate backfill or pelleted filling, offer information about the bioerosional process(es). Branching structures on cortical bone are present in canals and furrows. Where the trace penetrates spongy bone, branching structures are present in tunnels and connecting internal chambers. The common patterns of occurrences are individual, paired, grouped, overlapping, lined and arcuate. The site of emplacement may be in cortical or spongy bone, articular surfaces, internal bone microstructures and external bone anatomical structures.


76

ROY PLOTNICK1

Modeling the Movement Paleoecology of Burrowing Organisms

1Earth and Environmental Sciences, University of Illinois at Chicago, 834 W. Taylor St., Chicago, IL 60607 USA E‐mail: [email protected] Type of Presentation: Talk Research on movement by biologists has heavily focused on the passage across the land surface by large mammals or through the air by birds or insects. In contrast, movements within substrates and their resulting traces are the nearly exclusive domain of ichnologists. Nevertheless, the conceptual frameworks developed by behavioural biologists—in particular that of movement ecology—can be fruitfully applied to movements during burrowing. This structure includes the external environment of the burrowing organism, its capacity to detect the physical, chemical and biological properties of its surroundings and its internal state. The burrow is the movement path resulting from these interactions. A new version of the model TraceMaker (Plotnick 2003, 2005) has been used to examine 3‐D movements within substrates. The model produces various patterns of resources that vary both laterally and with depth in a simulated seafloor. It also can create multiple simulated organisms that “compete” for resources. The model is very flexible and allows the testing of numerous “what if” scenarios. For example, the onset of vertical burrowing is one of the key events in the Cambrian radiation. Simulations allow testing the extent to which this required behavioural innovations.


77

LUIS IGNACIO QUIROZ1, KOJI SEIKE2, LUIS ALBERTO BUATOIS1, MARIA GABRIELA MÁNGANO

1 AND CARLOS

JARAMILLO3

The Past as a Key to the Present: Searching for an Elusive Worm in the Tropics

1University of Saskatchewan, Department of Geological Sciences, 114 Science Place, Saskatoon SK S7N 5E2, Canada 2Coastal and Estuarine Sediment Dynamics Group, Port and Airport Research Institute, 311 Nagase, Yokosuka, Kanagawa 239‐0826, Japan 3Smithsonian Tropical Research Institute, Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 0843‐03092 & # 8232, Balboa, Republic of Panama E‐mail: [email protected] Type of Presentation: Talk Although trace fossils are typically regarded as the expression of changes in paleoenvironmental conditions, their application to paleoclimatic reconstructions is limited despite the huge differences in environmental conditions that we see today between low and high latitude settings. The opheliid polychaetes Euzonus mucronata and Ophelia limacina construct incipient Macaronichnus in high‐energy, intertidal and shallow‐subtidal environments along the Pacific coast of North America and Japan. Other Euzonus species living in vast numbers in sandy beaches have also been reported from New Zealand, Southern Brazil, Uruguay, Argentina and Chile. The present‐day distribution of these polychaetes is consistent with the known distribution of Macaronichnus in the fossil record, which shows a restriction to high‐ to intermediate‐latitude shorelines. However, its occurrence in the Neogene of Venezuela is highly anomalous and indicates that such structures are not related to high latitudes, but to nutrient‐rich cold water resulted from coastal upwelling, an oceanographic condition that was widespread in the Caribbean prior to the final closure of the Panama Seaway in the Pliocene. To test this new interpretation based on the fossil record, several trenches and sediment peels were made in two high‐energy beaches, with different oceanographic conditions, along the Pacific (upwelling) and Caribbean (non‐upwelling) coast of the Central American Isthmus. Interestingly, incipient Macaronichnus were only found on the Pacific coast, providing further evidence of the occurrence of Macaronichnus in connection with upwelling in the tropics. This finding demonstrates that sometimes the past may be the key to the present, an example of reverse uniformitarianism.


78

ANDREW K. RINDSBERG1 AND ANTHONY J. MARTIN2

Caster’s Plasters: Kenneth Caster’s Neoichnological Experiments on Limulids in the 1930s

1University of West Alabama, Dept. of Biological & Environmental Sciences, Station 7, University of West Alabama, Livingston, AL 35470, USA 2Emory University, Department of Environmental Studies, Emory University, Atlanta, GA 30322, USA E‐mail: [email protected] Type of Presentation: Talk In the 1930s, Kenneth Caster was one of a small but enthusiastic group of North American paleontologists who applied actualistic experimentation to their research on Paleozoic organisms. While Caster was engaged in deciphering Devonian‐Mississippian stratigraphy in Pennsylvania, a friend at the Pennsylvania Geological Survey, Bradford Willard, announced the discovery of the oldest known vertebrate footprints, Paramphibius, in the Late Devonian 'Chemung formation'. Caster soon realized, however, that the footprints (now called Kouphichnium) were instead made by limulids. In order to debunk Willard’s spectacular discovery, he thoroughly compared modern and ancient limulid trackways in a study that remains as one of the classics of ichnological literature. Caster made plaster‐of‐Paris casts of modern Limulus polyphemus trackways on clay substrates of various consistencies to document their similarities to Paramphibius and other fossil trackways. These casts, which are now at the Cincinnati Museum of Natural History, reveal Caster’s confident and methodical approach to a neoichnological problem. Our photographs and descriptions of limulid locomotion on the Georgia coast not only corroborate Caster’s work, but extend it into new areas. We have documented a wide variation of trackways with different growth stages of Limulus polyphemus, demonstrating how ontogeny within a single limulid species can result in considerable ichnodiversity. In short, today’s observations of limulid behaviour can be linked with the pioneering work of Caster, a lesson in following the footsteps of ichnologists well before us.


79

WILLIAMS RODRIGUEZ1,2 AND LUIS A. BUATOIS1

Ichnology, Facies Analysis and Sequence Stratigraphy in Paleoenvironmental Characterization

of Marginal Marine Reservoirs: Oficina Formation in the Orinoco Oil Belt, Venezuela

1Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, Saskatchewan, Canada 2PDVSA‐CVP E‐mail: [email protected] Type of Presentation: Poster Despite the economic importance of the Oficina Formation of the Orinoco Oil Belt as one of the most important hydrocarbon reservoirs in Venezuela and the world, little is known about its sedimentological, ichnological and sequence‐stratigraphic aspects. For this project, 2600 feet of well cores were analyzed in detail. The Oficina Formation has been subdivided into three members: lower, middle and upper. The lower member consists mainly of lowstand, low‐sinuosity fluvial‐channel deposits. Only root trace fossils were identified. The middle member is much more heterogeneous, both vertically and laterally, comprising high‐sinuosity fluvial‐channel, tidal‐flat, tidal‐channel and bay and coastal‐plain deposits, stacked forming a retrogradational package and representing the transgressive systems tract. The middle member is characterized by the impoverished Cruziana Ichnofacies, reflecting brackish‐water conditions. This member is thought to represent deposition in a tide‐dominated estuary. The upper member consists predominantly of highstand deltaic deposits, stacked forming a progradational pattern. These deposits locally show intense bioturbation with predominance of continental trace fossils, of the Scoyenia Ichnofacies.


80

FRANCISCO J. RODRÍGUEZ‐TOVAR1, ALFRED UCHMAN2, XABIER ORUE‐ETXEBARRIA3

AND ESTÍBALIZ APELLANIZ3

Ichnological Analysis at the Danian‐Selandian Boundary Interval in the Sopelana Section

(Basque Basin, W. Pyrenees): Approaching Palaeoenvironmental Conditions

1Departamento de Estratigrafía y Paleontología, Universidad de Granada, Avd. Fuente Nueva s/n, 18002, Granada, Spain 2Jagiellonian University, Institute of Geological Sciences Oleandry Str. 2a, PL‐30‐063 Kraków, Poland 3Departamento de Estratigrafía y Paleontología, Facultad de Ciencia y Tecnología, Universidad del País Vasco E‐48080 Bilbao, Spain E‐mail: [email protected] Type of Presentation: Talk Ichnological analysis has been conducted in the Danian‐Selandian (D‐S) transition from the Sopelana section (Basque Basin, N Spain). The trace fossil assemblage is relatively scarce and low diversity, with five ichnogenera – Chondrites, Planolites, Thalassinoides, Trichichnus and Zoophycos – all of which cross‐cut a diffuse, burrow‐mooted background. This assemblage is assigned to the Zoophycos Ichnofacies, occurring offshore in areas unaffected by turbiditic sedimentation. This accords with the generalized hemipelagic limestones, marlstone and marls of the studied succession, deposited in a deep‐bathyal environment, at around 1000 m depth for the adjacent Zumaia section. The generalized presence of a burrow‐mottled background and then the absence of sedimentary lamination, is evidence of favourable habitat conditions for macrobenthic tracemakers; corresponding to a normal burrowing tiered community associated with oxic conditions and normal benthic food availability. Absence of significant stratigraphic variations in the ichnological features could be related to the absence of significant perturbations, at least of those affecting the macrobenthic environment. Relative sea‐level fluctuations and/or global warming have being the most frequent proposed events to induce environmental fluctuations at the D‐S boundary transition. Ichnological data reveals the minor incidence of the “probable” D/S boundary global event on the macrobenthic environment. The most evident phenomenon registered in the Basque Basin during the D/S boundary is a major sea‐level fall at the end of the Danian, which is registered in the whole Pyrenean domain. Associated with this sea‐level phenomenon and the detrital input, fluctuations in depositional and ecological parameters can be expected, as in nutrients availability, oxygenation and/or salinity. The comparative lower impact in the macrobenthic habitat can be associated to a deeper‐open marine depositional setting, as that corresponding to the Sopelana and Zumaia sections. A possible hyperthermal event can be not definitively discarded, but may be of lesser importance.


81

SERGEY ROZHNOV1

Evidence of Symbiotic Myzostomid Settlements in Early Paleozoic Echinoderms

1Borissiak Paleontological Institute RAS Profsoyuznaya 123, Moscow, 117997, Russia E‐mail: [email protected] Type of Presentation: Talk Myzostomids are a group of marine animals, close to the annelids, living in close symbiosis with modern echinoderms. There is a particularly large variety of different mizostomid settlements on crinoids. Some myzostomids incorporate into the skeletal tissue of crinoid arms, or stem, causing a overgrowth of skeletal tissue in a specific circular depressions surrounded by a projecting ridge. These growths on crinoids can be tracked in the fossil record until their first appearance in the Ordovician. However, in the Ordovician crinoids did not dominate and myzostomid settlements on them were rare. Abundant traces of myzostomid settlements were found on the theca of the Middle Ordovician eocrinoid Rhipidocystis baltica, a dominant species in the echinoderm communities of the Volkhov Regional Stage of Baltica. They are represented by cylindrical depressions 0.5‐1.5 mm in diameter, surrounded by a small ridge. Single or mass settlements on theca are located mainly on the marginal parts of the thickened thecal plates, but sometimes occurred on the thinner central plates. Myzostomid infestation in Rhipidocystis from the Regional Stage is about 5%. Similar settlements were found at the thecal surface of Maennilia estonica from the Upper Ordovician of Estonia. There are numerous depressions (about 0.5 mm in diameter) in many plates from the lower surface of the theca in the center of a small bulge. In spite of larger body size of Maennilia, these pits are usually smaller in size than those ones of Rhipidocystis. Apparently this is associated with a smaller size of plates in Maennilia. Similar pits on the top of the small tubercles on isolated thecal plates of gogiid eocrinoids were found in the Middle Cambrian of Australia. The shapes of these growths tubercules are similar to the Ordovician, but their size is almost one order smaller. But in the same proportion gogiid eocrinoids were smaller than Ordovician crinoids and eocrinoids Rhipidocystis. Apparently, in this case, we observe co‐evolution of the size of the hosts and their symbionts.


82

MARIA SAVITSKAYA

Chondrites Brongiart, 1828 from Middle Ordovician Limestones (St. Petersburg Region, Russia) and its Interpretation

E‐mail: [email protected] Type of Presentation: Poster Chondrites Brongiart, 1828 is ichnofossils of the transgressive tract Volkhov sequence (unit “Zheltiaki Limestone”), lower‐middle Ordovician age. The Volkhov sequence coincides with the Volkhov regional stage. The main outcrops of this stage is located in quarries and river valleys in the northwest of the Russian platform where

Ordovician rocks occupy an elevated area called the “Ordovician Plateau”.The “Zheltiaki Limestone” consists of up to 1.6 m thick clayey limestone, yellow, red or variegated in colour, interbedded with clay. Red coloured, with the organic buildups of mud mound type (first sponge/algal reefs) “Zheltiaki Limestone” represents warm‐water conditions. In order to monitor the hydrobionts and their traces have been studied aquariums of the oceanarium St. Petersburg. In the aquarium, which were presented to a coral reef found traces of Chondrites sp. In the study of soil were found copepods subclass Copepoda, inside Chondrites sp. If we assume that fossil traces of Chondrites Brongiart, 1828 submitted by copepods, which lived in the Ordovician basin Baltoscandia in similar conditions, we can to make the following conclusions. In the Middle Ordovician in this part of the basin Baltoscandia was normal salinity, temperatures average 20 degrees, and deep‐sea anaerobic conditions prevailed clay sedimentation. Chondrites Brongiart, 1828 are feeding traces of copepods.


83

ELIZABETH R. SCHATZ1,2, MARIA GABRIELA MANGANO1, ALEC E. AITKEN3 AND LUIS A. BUATOIS1

Response of Benthos to Stress Factors in Holocene Arctic Fjord Settings: Maktak, Coronation

and North Pangnirtung Fjords, Baffin Island, Canada

1Department of Geological Sciences. University of Saskatchewan. 114 Science Place, Saskatoon, SK, S7N 5E2, Canada 2Department of Earth Sciences. Memorial University of Newfoundland. 300 Prince Philip Drive, St. John’s, NL, A1B 3X5, Canada 3University of Saskatchewan, Department of Geography and Planning. University of Saskatchewan. 117 Science Place, Saskatoon, SK, S7N 5C8, Canada E‐mail: [email protected] Type of Presentation: Poster Maktak, Coronation and North Pangnirtung fjords are situated on the Cumberland Peninsula, Baffin Island, Canada, having a common freshwater source from the Penny Ice Cap. Bottom photographs were examined to identify epifaunal and shallow endobenthic trails and burrow openings exposed on the substrate surface. These were compared to biogenic sedimentary structures revealed through X‐radiograph images and direct observations of Lehigh core samples. Intermediate‐ and deep‐tier structures characterize the ichnofabrics of the glaciomarine sediments. Extensive bioturbation by the shallow‐tier epibenthic tracemakers, most notably ophiuroid echinoderms (brittlestars), has destroyed much of the primary sedimentary fabric (i.e. lamination) resulting in homogenous silty clay sediments. The dominant deep‐tier structure consisting of an open, three‐dimensional boxwork burrow system was observed to be the most pervasive biogenic structure within the core samples. Environmental factors influencing the biological community in these modern high latitude fjords are notably different from conditions described in Paleozoic and Cenozoic fjord environments. An increasing number of recent studies are expanding significantly on the fjord database and provide a basis for the reconstruction of the currently proposed ichnofacies model, accommodating the complexity and diversity of fjord settings.


84

KOJI SEIKE1, YUTA SHIINO2 AND YUTARO SUZUKI3

Tubular Trace Fossil Armoured with Crinoid Stem Plates from Upper Permian Shallow Marine

Deposits of Northeastern Japan

1Port and Airport Research Institute, 3‐1‐1 Nagase, Yokosuka, Kanagawa 239‐0826, JAPAN 2University Museum, University of Tokyo, 7‐3‐1, Hongo, Bunkyo, Tokyo 113‐0033, Japan 3Institute of Geosciences, Shizuoka University, 836 Ohya, Suruga, Shizuoka, 422‐8529, Japan E‐mail: [email protected] Type of Presentation: Poster In the presentation, we report a horizontal tubular fossil burrow whose wall consists of numerous crinoid stem plates from the Upper Permian Kamiyasse Formation of northeastern Japan. The trace fossil described here measures 40– 70 mm in length and 7–20 mm in diameter. The outer wall of the tube is characterized by numerous skeletal fragments, with most being crinoid stem plates (2 mm in diameter) and lesser fragments of brachiopods and other invertebrates. The inner wall of the tube is covered with a smooth lining devoid of crinoid skeletal elements. Because stalked crinoids mainly inhabited shallow water settings prior to the Cretaceous, it is possible that additional specimens of this trace fossil will be discovered from deposits of various ages and locations.


85

KOJI SEIKE1, ROBERT G. JENKINS2, HIROMI WATANABE3, HIDETAKA NOMAKI

3 AND KEI SATO4

A New Method for Deep‐Sea Neoichnology:

In‐situ Burrow Casting

1Port and Airport Research Institute 3‐1‐1 Nagase, Yokosuka 239‐0826, Japan 2Yokohama National University 79‐1 Tokiwadai, Yokohama 240‐8501, Japan 3Japan Agency for Marine‐Earth Science and Technology 2‐15 Natsushima‐cho, Yokosuka 237‐0061, Japan 4University of Tokyo 7‐3‐1 Hongo, Tokyo 113‐0033, Japan E‐mail: [email protected] Type of Presentation: Talk Improving our understanding of trace fossils requires analysis of their modern analogs. Although the deep sea is the largest ecosystem on Earth, burrow casting –– an extremely useful approach to understanding the burrow morphology –– has never been conducted in the environment to date. Previous studies revealed morphology of incipiently fossilized burrows in cored samples. However, it is generally not possible to observe active burrows by the coring method. This is because large organisms in the sediment often show escaping movements, downward or upward, during coring, thereby disrupting the original burrow structures or life positions. Furthermore, the observable volume is limited due to the size of the core and the device used for analysis. We overcame these problems by in situ burrow casting. Here we describe the morphology of a large burrow, obtained by in situ burrow casting at a hydrocarbon‐seep site and a non‐seep site at water depths of 1173 and 1455 m, respectively. Deep and complex burrows are abundant at both sites, indicating that the burrows introduce oxygen‐rich seawater into the deep reducing substrate, thereby influencing benthic metabolism and nutrient fluxes and providing an oxic microhabitat for small organisms. This is, to our knowledge, the first study to examine in situ burrow morphology at the deep‐sea, providing new clues to deep‐sea trace fossils.


86

HEMANTA SINGH RAJKUMAR1

Trace Fossils and Shoreface Model of Laisong Flysch Sediments of Manipur, Indo‐Mymar

Ranges, India

1United College, Manipur University Lambung, Chandel ‐ 795127, Manipur, India E‐mail: [email protected] Type of Presentation: Talk The Barail Group of sediments of Manipur (23º 50′ to 25º 55′N latitude and 93º to 94º 45′E longitude) in northeast India belongs to the Flysch Belt of Indo‐Myanmar Ranges. The Group is divided into three divisions: the Laisong, Jenam and Renji. The thickness of this whole sequence is about 3,000m. The Barail Group has a gradational (with local tectonic) contact with the older Disang Group of the IMR Flysch Belt. The paper is an attempt to reconstruct a depositional basin model in which the Laisong Formation was deposited, using trace fossils of Skolithos‐Cruziana mixed Ichnofacies, Cruziana Ichnofacies, Skolithos Ichnofacies and Nereites Ichnofacies in a descending abundance as tools for palaeoenvironmental interpretation. The Laisong Formation is the lowermost division of the Barail Group, is considered to be Auversian‐Bartonian in age, and has a thickness of ~1,200m. The predominance of Skolithos‐Cruziana mixed Ichnofacies suggests a sedimentary basin with a shallow marine estuarine environment in particular, and a foreshore to lower offshore zone. Associated sedimentary structures indicate strong tidally affected sub‐littoral settings with significant and complex wave activity and the sedimentary facies throughout the studied sections show a general upward coarsening indicating upward shoaling facies succession. The accommodation space for the approximately 1,200m thick sequence may be explained from the tectonic effect. The basin must then have been associated with cyclic stretching and deepening, providing the accommodation space and at the same time maintaining the depositional setting in the foreshore to lower offshore zone with varying low to high storm dominated environment characterized by moderately high oxygenated conditions.


87

HEMANTA SINGH RAJKUMAR1, KUMAR SINGH KHAIDEM2

AND IBOTOMBI SOIBAM3

Trace Fossils and Palaeoenvironment of Barail Flysch, Manipur, Northeast India

1Department of Geology, United College, Chandel ‐ 795127, Manipur, India 2Department of Geology, D.M. College of Science, Imphal ‐ 795001, Manipur, India 3Department of Earth Sciences, Manipur University, Canchipur ‐ 795003, Manipur, India E‐mail: [email protected] Type of Presentation: Talk The 3000m thick successions of Barail flysch sediments (Barail Group) of the Tertiary, Late Eocene to Early Oligocene, of Manipur state in the Northeast India comprise three formations. The Laisong (~1200m) is made up of shale, silty shale, siltstone, and fine sandstone intercalations; the Jenam (~1000m) is mainly composed of carbonaceous shale and thick bedded fine sandstone; and the Renji (~800m) comprises thick bedded sandstone. The whole sequence has long been regarded as deep marine deposits, and there is no consensus regarding the bathymetric position of the basin where such a thick column of sediments was deposited. Analyses of the varied trace fossils like Aulichnites sp., Bergaueria hemispherica, Brookvalichnus sp., Chondrites targionii, Furculosus sp., Gordia marina, Gyrochorte comosa, Helminthoida sp., Helminthopsis tenuis, Nereites missouriensis, Ophiomorpha nodosa, Palaeodictyon strozzi, Palaeophycus striatus, Palaeophycus tubularis, Phycodes palmatus, Planolites beverleyensis, Protovirgularia rugosa, Skolithos linearis, Taphrhelminthopsis auricularis, Thalassinoides horizontalis and Thalassinoides paradoxicus from different localities of the Barail Group indicate, in descending abundance, a Skolithos‐Cruziana mixed Ichnofacies, Cruziana Ichnofacies, Skolithos Ichnofacies, Nereites Ichnofacies and Trypanites Ichnofacies. The predominance of a Skolithos‐Cruziana mixed Ichnofacies suggests a depositional basin of shallow marine estuarine environment in particular, and a foreshore to lower offshore zone in general, with varying low to high storm dominated environment characterized by moderately high oxygenated conditions.


88

BIRENDRA P. SINGH1 AND RAVI. S. CHAUBEY1

Sedimentation Pattern, Energy Level and Preservation of the Cruziana Ichnofacies in the Early

Cambrian Nagaur Sandstone Formation (Marwar Supergroup) Bikaner‐Nagaur Basin, Rajasthan

1Center for Advanced Study in Geology, Panjab University Sect‐14, Chandigarh, India E‐mail: [email protected] Type of Presentation: Poster The preservation style of the Cruziana Ichnofacies in the Nagaur Sandstone Formation (Early Cambrian) is evaluated in terms of sedimentation pattern, energy level of deposition and the relationship with the preserved size of the trace fossils. This study identifies three potential preservation levels with variable degree of depositional energy, fluctuation in sedimentation pattern and relative size of the preserved traces. These levels include: 1) the top of the fine grain reddish sandstone which is normally overlapped by thin layers of greenish shale and further upward overlain by the pseudo‐conglomerate layer, indicating a shift of depositional energy level from low to high. This level preserves medium‐sized Rusophycus and Cruziana traces; 2) the maroon colored micaceous fine grained silty shale levels with green streaks of shale which normally cap the fine‐ to medium grained sandstone beds, indicating low energy deposition. These levels preserve small Cruziana, Rusophycus and Diplichnites traces. However, the burrows pattern are large in size at this level; and 3) the dark reddish fine to medium grained sandstone preserving large scale cross beds indicating medium‐high energy level of deposition and overlapped by the thin layer of fine reddish shale. This level preserves large size traces of the Cruziana, Rusophycus, Diplichnites and small burrows.


89

MICHAŁ STACHACZ1 AND ALFRED UCHMAN1

Ichnological Record of the Frasnian‐Famennian Boundary interval in the Kowala Quarry (Holy

Cross Mountains, Poland)

1Institute of Geological Sciences, Jagiellonian University, Oleandry 2a, 30‐063 Kraków E‐mail: [email protected] Type of Presentation: Poster Massive reef and thick‐ to medium‐bedded reef‐talus limestones form the lower part of the Frasnian‐Famennian boundary (F‐F) interval in the Kowala Quarry. About the F‐F, they pass upward into brown‐reddish medium‐bedded limestones intercalated by thin layers of marls, marls and bed couplets composed of marls and silty shales. There are also a few horizons of beds with flints, which are an equivalent of the Kellwasser event. The F‐F is identified here within a characteristic bed that contains two horizons of flints and is well documented by geochemical data in the previous studies. Beds below the F‐F are generally bioturbated, but ichnofabrics are poorly visible here in micritic limestones and packstones with large bioclasts, also due to diagenetic obliteration. Trichichnus is common, especially 1‐1.3 m below the F‐F. About 0.6 m below the F‐F, the first distinctly horizontally laminated reddish limestones occur. Another distinctly laminated limestone is present between the two horizons of flints within the F‐F bed. About 2.5 m above the F‐F, the lithology changes: dark‐grey and almost black marls, siltstones and rare isolated beds of grey limestones appear. The dark‐grey and almost black marls are distinctly horizontally laminated, pyritized and do not contain trace fossils and bioturbational structures. The isolated beds of grey limestone within the dark marls contain trace fossils and non‐identified bioturbational structures in a few beds. Some marly beds are partly bioturbated. One of the limestone beds shows numerous ?Chondrites isp., and a few other beds contain unidentified fodinichnia. The laminated, non‐bioturbated beds of marls with pyrite indicate anoxia on the seafloor. It is interesting that the first anoxic event occurs below the F‐F. The presence of trace fossils and bioturbational structures is interpreted as an improvement of oxygenation. However, their low diversity suggests unfavourable environment for most organisms.


90

LINA M. STOLZE1 AND DR. SAMUEL J. BENTLEY2,1

Bioturbation in Continental Shelf and Rise Sediments of the Gulf of Maine

as Revealed by X‐ radiography 1Memorial University of Newfoundland, Department of Earth Sciences, Memorial University of Newfoundland, St. John's, NL A1B 3X5, Canada 2Louisiana State University, Department of Geology and Geophysics, E307 Howe Russel Geosciences Complex, Louisiana State University, Baton Rouge, Louisiana, USA 70803 E‐mail: [email protected] Type of Presentation: Poster The marine benthic ecosystem, a gateway to sedimentary carbon storage and a large repository of ecosystem nutrients, is constantly altered and influenced by bioturbation processes. In addition, the abundance and diversity of the macrofauna, a main bioturbator in marine sediments, is controlled by complex interactions among various biotic and abiotic environmental factors such as organic matter supply, temperature, salinity and substrate type. In this study we examine the distribution and characteristics of bioturbation in recent marine sediments from depths of 150 m to 3000 m between the continental shelf and rise localities in the Gulf of Maine region. In particular, sediment cores were collected with a multi‐corer from Crowell Basin, Georges Basin, Jordan Basin, Roseway Basin, Northeast Channel and Fan on two cruises in 2009 and 2010 onboard the Canadian Coast Guard Vessel CCGS Hudson. Biogenic sedimentary structures produced by endobenthic macrofauna were observed using X‐ray imaging of sediment slabs prepared from collected cores. Abiotic and biotic parameters, including total organic carbon, total nitrogen and chlorophyll‐a concentration, δ13C and sediment particle size, were analyzed in an attempt to describe the benthic environmental conditions of each sampling site. Preliminary results show that sediments from most sites were actively mixed most likely by macrofaunal organisms. We observed higher abundances of burrows and burrow‐mottling structures in Crowell and Georges Basin, which can be attributed to a relatively high organic matter supply that drives bioturbation in these regions.


91

GEORGINA TARI1, ARPAD DAVID1 AND ROZALIA FODOR2

Feeding and Nesting Holes of Woodpeckers (Aves, Picidae) in Middle Miocene Age Petrified Woods from North‐Hungary

1Karoly Eszterhazy College, Leanyka u. 6., H‐3300 Eger, Hungary 2Matra Museum, Kossuth u. 40., H‐3200 Gyöngyös, Hungary E‐mail: [email protected] Type of Presentation: Poster The authors, while were examining the petrified wood collection of the Matra Museum (Gyöngyös, Hungary) looking for traces of xylophagous insects found two silicified stems bearing large cavities referring to the activity of woodpeckers (Aves, Piciformes). Both of the petrified wood remains have been found in Miocene, coarse grained, sandy deposits. The characteristic features of the examined petrified wood fragments and the trace fossils are as follows. 1. The feeding hole: The petrified wood is 2 m high, 0.55 m wide and 0.24 m thick. Its finding place is Mikófalva, Bükk Mountains, North‐Hungary. Age: Lower Miocene (Garáb Schlieren Formation). The original tree belonged to Pinus sp. The cavity is elongated, oval. The hole’s diameters are: 29.2 cm and 11.3 cm; its depth is 13.6 cm. 2. The nesting hole: The petrified wood fragment is 38.3 cm long, 8.4 cm wide and 6.3 cm thick. Its locality is Rátka, Tokaj‐Eperjes Mountains, North‐Hungary. Age: Middle Miocene (Erdőbénye Formation, Rátka Quartzite Member). The tree belonged to the Magnolidae. The hole itself is partly preserved since the petrified wood is fragmentary. The form of the trace is elongated, its length is 32.1 cm. The diameter of the entrance of the hole could be 10.9 cm (counted). The trace is parallel to the tissues of the former wood. Woodpecker body fossils are dated back to the Early Oligocene. According to the evolution of the group and the morphology of the feeding and nesting holes of modern Picidae, we could assume the presence of woodpeckers in the Middle Miocene forest ecosystem.


92

YUSUKE TAKEDA1 AND KAZUSHIGE TANABE1

Ventral Bite Marks in the Early Jurassic Ammonoids from the Nishinakayama Formation in the

Toyora Area, Western Japan

1The University Museum, The University of Tokyo, 7‐3‐1 Hongo Bunkyoku, Tokyo 113‐0033 Japan E‐mail: [email protected]‐tokyo.ac.jp Type of Presentation: Talk Ammonoids, an extinct group of cephalopods, flourished in the world's oceans during the Early Devonian to the end of the Cretaceous. They are suitable organisms to investigate the predation‐prey interaction through geological time. Predatory marks on the ventral side of the body chamber ("ventral bite mark") have been found in some ammonoids, but have not yet been analyzed quantitatively in individual ammonoid assemblages. Here we report quantitative data of shell breakage in an ammonoid assemblage from the Early Toarcian (Early Jurassic) Nishinakayama Formation in the Toyora area, west Japan. The strata yielded the assemblage consist mostly of well‐laminated, bituminous black shales that were deposited in an oxygen depleted shelf basin of the Northwest Panthalassa, under the influence of the Early Toarcian oceanic anoxic event. Among the total of 1,143 specimens belonging to 7 species of 5 genera examined, an apparent shell breakage was recognized in 28 specimens, only 2.5% for the frequency of occurrence to the total assemblage. All of the breakages occur on the ventral side near the base of the almost complete body chamber. These breakages are similar in overall shape to the "ventral bite marks" previously reported in Jurassic and Cretaceous ammonoids. This fact, as well as the low‐energy depositional setting of the ammonite‐bearing black shales, strongly suggests that the ventral shell breakages observed in these ammonoids were not caused by post‐mortem processes but by a predator's attack. Because an anoxic bottom environment is suggested for the Nishinakayama Formation, these ammonoids were predated by nektonic animals such as teleost fishes and/or other larger ammonoids with calcified jaws, which aimed at the muscle attachment part prior to pull out the edible soft tissues. The reason for the lower frequency of the "ventral bite mark" observed in the ammonoid assemblage examined is presumably related to the absence of durophagous benthic predators.


93

MICHELLE THOMS1 AND DUNCAN MCILROY2

Three Dimensional Morphological Characterization of the Trace Fossil Rosselia

1ConocoPhillips Canada, Gulf Canada Square, 401–9th Avenue S.W. Calgary, Alberta. T2P 3C5. Canada 2MUN Ichnology Research Group, Department of Earth Sciences, Memorial University of Newfoundland, St John's, NL. A1B 3X5. Canada E‐mail: [email protected] Type of Presentation: Talk The ichnogenus Rosselia is recognized as a vertically oriented burrow that consists of a cone‐ or funnel‐ shaped portion with a central shaft with meniscate backfill. The conical portion of Rosselia has been inferred to consist of either imbricate concentric layers of matrix surrounding a cylindrical shaft, or helicoidal swirls, both tapering downwards. Rosselia is a common trace fossil routinely used as a paleoenvironmental indicator and while its morphology has been theorized by many ichnologists, a complete understanding of the internal morphology is lacking. In order to create a deterministic model of Rosselia serial grinding, photography and three‐dimensional modeling were all employed to create a three‐dimensional model of the trace fossil. Halos surrounding the Rosselia burrows could imply a detritus feeding mechanism as opposed to a suspension or deposit‐feeding mechanism. Horizontal branches emanating from the vertical Rosselia burrows are interpreted to be that of an Asterosoma burrow. Due to the presence of Asterosoma, these two trace fossils are interpreted to be a part of the same burrow system. These two trace fossils are often found in the same beds, meaning this model could have wide application. Based on these new characteristics found in Rosselia, it will be pertinent to re‐visit the type material.


94

ALFRED UCHMAN1 AND JANUSZ KOTLARCZYK2

Ichnological and Ichthyological Proxies for Palaeo‐oxygenation in the Skole Basin

(Carpathians, Poland) During the Oligocene

1Institute of Geological Sciences, Jagiellonian University, Oleandry 2a; 30‐063 Cracow, Poland 2Department of General Geology, Environment Protection and Geotourism, Faculty of Geology, Geophysics and Environment Protection, AGH – University of Sciences and Technology Mickiewicza 30; 30‐059 Cracow, Poland E‐mail: [email protected] Type of Presentation: Talk The basically anoxic, mostly black or brown fine‐grained sediments of the Menilite Formation (Oligocene–Early Miocene) in the Skole and Subsilesian Nappes contain thin layers of bioturbated green or grey‐green mudstones of the background sediments, some of which contain trace fossils: Halimedides annulata, Multina isp., Palaeophycus?tubularis, ?Planolites isp., Rhizocorallium isp., Trichichnus isp. and Zoophycos isp. The suite Trichichnus–Palaeophycus–(Multina, Halimedides)–Rhizocorallium indicates an increase in oxygenation of sediments. The contribution of different ecological groups of fishes, including epipelagic, bathypelagic, benthopelagic, neritic and reef and demersal taxa changes significantly in the stratigraphic column of the Menilite Formation. The absence or reduction of bathypelagic fishes points to anoxia in the water column. The combination of ichnological and ichthyological data and incorporation of data on benthic foraminifers allowed a reconstruction of oxygenation changes in sediment and water column during sedimentation of the Menilite Formation during Oligocene. The total anoxia in theseafloor and water column, referred to the extremely rich organic productivity, was present only during the ichthyofaunal Zone IPM2. The anoxia present only on the seafloor or upper slope, referred partly to upwelling events that took place during sedimentation of the upper part of the Menilite Formation.


95

JOONAS VIRTASALO1, MARTIN WHITEHOUSE2 AND AARNO KOTILAINEN1

Sulfur and Iron Isotope Heterogeneity in the Pyrite Fillings of Holocene Worm Burrows

1Geological Survey of Finland P.O. Box 96, FI‐02151 Espoo, Finland 2Swedish Museum of Natural History P.O. Box 50007, SE‐10405 Stockholm, Sweden E‐mail: [email protected] Type of Presentation: Poster X‐radiographs of the upper part of Holocene post‐glacial lacustrine clays in the Baltic Sea basin display intense burrow mottling with discrete Palaeophycus, ‘Mycellia’ and rare Arenicolites. Small burrow‐like and irregularly‐shaped concretions were separated from these clays. The burrow‐like concretions have cores of framboidal pyrite and crusts of poorly crystalline FeS2. The pyrite framboids were formed in reducing worm‐burrows in oxic surface sediments, where organic coatings on the burrow walls supported intense microbial activity. Ion microprobe analyses of the core framboids display δ34S values close to marine sulfate (~+21‰), indicating episodic saline inflows from the North Sea (World Ocean) as the sulfate source. The FeS2 crusts on the framboids have significantly lower δ34S values (~–20‰), indicating later precipitation from pore‐water H2S that was strongly enriched in

34S by bacterial sulfate reduction. δ56Fe values of the framboids are exceedingly low, down to –3.1‰, while the crusts have higher δ56Fe values (–2.1 to +1.4 ‰). δ56Fe values reflect the preferential capture of 54Fe to pyrite in the diagenetic sequence and the 56Fe‐enrichment of remaining pore water. Available data cannot discriminate between microbial and abiotic pathways in the Fe‐isotope fractionation. However, microbial Fe reduction pathways generally are faster, which leads us to propose a stronger microbial contribution during the framboid precipitation in the earliest diagenesis. The irregularly‐shaped concretions were formed in sediment pores not enriched in organics. They display extremely low δ34S values (>–45.7‰), indicating late precipitation from strongly 32S‐enriched H2S. Their extremely high δ56Fe values (< +4 ‰) support precipitation at a later diagenetic stage.


96

ANDREAS WETZEL1

Burrows Storing an Otherwise Lost Sedimentary Record

1Geologisches Institut der Universität Basel, Bernoullistrasse 32, CH‐4056 Basel, Switzerland E‐mail: [email protected] Type of Presentation: Talk Burrowing organisms are known for churning and disturbing the initially layered stratigraphic record. However, in some instances traces store a sedimentary record that is otherwise not preserved. Such information is found in traces while living organisms actively filled their burrows or while open burrows were passively filled after abandonment. In the case of actively filled traces, burrow producers (selectively) transfer sedimentary particles from the seafloor into their burrows. Normally these particles form a thin layer on the seafloor, resultant from event deposition or seasonally sediment input. Such thin layers, however, have a high potential to be easily mixed with the sediment underneath, especially if the layer is thin and the sediment below is soft. If such layers, however, constitute the sediment surface for a while, surface‐feeding endobenthic animals transfer benthic food deposited on the layer together with layer material into their burrows because food particles adhere to non‐food particles and cannot purely be ingested. If burrows of at least temporarily surface‐feeding organisms penetrate deeply, they store the information about the sediment present on the previous seafloor in an otherwise bioturbationally homogenized deposit. Volcanic ash is among the best known material preserved in this way, but also organic detritus, foraminifera and other components have been found stored in burrows. In the case of passively filled traces, open, but abandoned tubes become filled by sediment settling from the water column or moving on the sediment surface from that the burrows pipe down. Such traces have strong walls when produced in not‐stable sediment or they were excavated into a stiff to hard substrate and hence, form part of the Glossifungites‐suite burrows. Ideally, during induration of an omission surface different types of burrows may record various phases of sediment bypass. The sequestered record within the burrows includes particles from sediment sheets that moved over shelves or areas being undersupplied with respect to sediment. Sometimes exotic material can be found, for instance, iron‐ooids occurring in micritic limestone, mud rich in planktonic foraminifera filling borings in oncoids, or tubes preserving a tidal record and thus, representing 'tubular tidalites', in otherwise totally bioturbated sediments. A brief check of the sedimentological literature suggests that the potential of burrow fill to unravel the incomplete stratigraphic record, especially in shallow‐water setting, appears to have been underestimated and hence, under‐investigated so far.


97

LOGAN A. WIEST1, ILYA V. BUYNEVICH1, DAVID E. GRANDSTAFF

1 AND DENNIS O. TERRY, JR.1

Ichnological Evidence for Dwarfism in Endobenthic Communities at the K‐Pg Interval in New

Jersey, USA: Paleoenvironmental Disturbance and Stratigraphic Implications

1Temple University, 326 Beury Hall, 1901 N. 13th, Street Philadelphia PA 19122 E‐mail: [email protected] Type of Presentation: Poster Thalassinoides diameters were measured at four sites that cross the Cretaceous‐Paleogene (K‐Pg) boundary along the New Jersey coastal plain. Within this regionally extensive, monospecific ichnoassemblage, the burrow size decreases abruptly from ca. 17.5 to 11.9 mm (n = 475) at a level 15 to 20 cm above the base of the glauconite‐rich Hornerstown Formation at the Inversand, Meirs Farm and Rancocas sites, corresponding with the base of the Main Fossiliferous Layer (MFL). The MFL is a ca. 10 to 20‐cm‐thick accumulation of vertebrate and invertebrate fossils that has been previously interpreted as a thanatocoenosis related to the end‐Cretaceous impact. At Tighe Park, our northernmost site, reduced shaft and tunnel diameter occurs within the ”Pinna Layer”, which is associated with one of the highest ammonite zones in North America and an iridium anomaly. The change in diameter likely indicates a decrease of thalassinid decapod crustacean body size. We interpret this abrupt shift in size as a result of dwarfing within the endobenthic community during the nutrient‐poor and low pH "Strangelove" ocean period following the bolide impact. Our localities span approximately 95 km of outcrop and the dwarfing trend is present at each site. Despite the difference in size, there is no change in framework geometry, with characteristic T‐ and Y‐junctions. Ichnofabric indices are found to generally increase up‐section at each site, suggesting a regional reduction in sedimentation rate, which is supported by a gradual increase in glauconite maturity. This study demonstrates that ichnology is an effective tool for identifying the K‐Pg boundary within sections where bioturbation has obscured other diagnostic criteria.


98

MAX WISSHAK1, ALINE TRIBOLLET2, STJEPKO GOLUBIC

3, JOACHIM JAKOBSEN4 AND ANDRÉ FREIWALD1

Experimental Evaluation of Bioerosional Ichnodiversity from Intertidal to Bathyal Depths in

the Azores

1Senckenberg am Meer, Marine Research Department, 26382, Wilhelmshaven, Germany 2Institut de Recherche pour le Développement, UMR IPSL‐LOCEAN 93143, Bondy, France 3Boston University, Department of Biology, Boston, MA 02215, USA 4Rebikoff‐Niggeler Foundation, 9900‐451, Horta Faial, Azores, Portugal E‐mail: [email protected] Type of Presentation: Talk In the temperate Azores carbonate factory, a substantial fraction of the skeletal components are re‐cycled by a remarkable biodiversity of biota producing bioerosion traces. To study this ichnodiversity, experimental substrates were exposed to colonization by epi‐ and endoliths along a depth gradient from 0 m to 500 m in the Faial Channel. The ichnodiversity comprises 56 ichnotaxa and –forms (11 attributed to cyanobacteria, 7 to chlorophytes, 8 to fungi, 11 to other micro‐chemotrophs, 4 to macroborers, 4 to grazers and 11 are attachment scars of epiliths). In the intertidal, strong hydrodynamic force, partial emersion and strong temperature fluctuation lead to the lowest ichnospecies richness. This contrasts with the highest diversity at 15 m under the most favourable conditions. Towards aphotic depths, depletion in ichnodiversity is due to restricted illumination and a slow‐down in ichnocoenosis development. Analyses of similarity (ANOSIM) were used to highlight variability of the relative abundance of bioerosion traces among depths, between substrate orientations and between exposure times. Similar to diversity, the abundance of traces decreases significantly with depth, with pronounced changes in ichnocoenosis composition. Ichnodiversity and abundances were much higher on up‐ versus down‐facing substrates, probably due to light limitation and gravitactic larval behaviour or better adhesion. Differences between years were low. Non‐metrical multidimensional scaling (NMDS) confirms the gradual shift in ichnocoenosis composition along the depth transect, with a clear distinction between orientations but little effect of exposure time. The present study demonstrates that statistical methods of biodiversity analysis are not per‐se restricted to fossil and recent biotaxa, but may well be applied also to ichnotaxa. In the analysis of trace fossil assemblages this approach supports the recognition of diversity patterns and their relation to environmental gradients.


99

LI‐JUN ZHANG1 AND YI‐MING GONG2

Ichnocoenosis of the Lower Devonian Pingyipu Formation in the Longmen Mountain, Sichuan

1Key Laboratory of Biogenic Traces and Sedimentary Minerals of Henan Province, Henan Polytechnic University, No.2001 Century Avenue, Jiaozuo, Henan, China 2State Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, China University of Geosciences No.388 Lumo Road, Honshan, Wuhan, Hubei, China E‐mail: [email protected] Type of Presentation: Poster The littoral‐neritic sediments of the Lower Devonian Pingyipu Formation in the Ganxi Section is enriched with ichnocoenoses, which consist of at least 11 ichnogenera: Arenicolites, Chondrites, Cylindrichnus, Diplocraterion, Palaeophycus, Planolites, Phycodes, Rhizocorallium, Rusophycus, Skolithos and Thalassinoides. The ichnocoenoses represent domichnia, fodinichnia and cubichnia. Based on the composition and distribution characteristics of these trace fossils and other facies indicators in host strata, five types of ichnocoenoses formed under different sedimentary environments have been recognized as follows: 1) Planolites‐Palaeophycus ichnocoenosis, which mainly consists of fodinichnia, was formed in a lower‐energy zone of nearshore; 2) Rusophycus‐Phycodes ichnocoenosis, which mainly consists of fodinichnia and cubichnia, was generated in lower‐energy zone of nearshore; 3) Chondrites‐Palaeophycus ichnocoenosis, which mainly consists of domichnia and fodinichnia, represented the lower‐energy and anoxic environment of lower nearshore; 4) Skolithos‐Cylindrichnus ichnocoenosis, which is characterized by dwelling burrows and represented higher‐energy foreshore; 5) Skolithos‐Diplocraterion ichnocoenosis, including dwelling and feeding burrows, was formed in lower‐energy of upper nearshore enriched with food.

ichnia 2012 abstract book. the 3rd international congress on ichnology

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