PREDATION IN MOLLUSCS: A MULTI-TAXON APPROACH USING NEONTOLOGICAL AND PALEONTOLOGICAL DATA by Devapriya Chattopadhyay A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Geology) in The University of Michigan 2009 Doctoral Committee: Professor Tomasz K. Baumiller, Chair Professor Daniel C. Fisher Professor Kyger C. Lohmann Assistant Professor Thomas F. Duda Jr. Assistant Professor Jeffrey A. Wilson Research Scientist Janice L. Pappas ACKNOWLEDGEMENTS I want to extend my sincere gratitude to my academic adviser Prof. Tomasz K. Baumiller who introduced me to the modern trends in Paleontology. I wish to thank Prof. Michal Kowalewski of Virginia Polytechnic Institute and State University and Prof. Lindsey Leighton of University of Alberta who helped me to carry out the neontological experiments. Special thanks to Dr. Daniel J. Miller and G. Alex Janevski for numerous valuable discussions that significantly improved my dissertation. UROP student Sarah Groat helped me in collecting data from the museum specimens. I would like to thank my collaborator Ms. Michelle Casey (Yale University) for her part in our joint study that I included as an appendix in this dissertation. I am indebted to Dr. John Huntley for sharing his data on Phanerozoic predation intensity (Chapter VI). I wish to thank Ms. Anne Hudon for her unrelenting help with all official procedures that could be quite challenging for an international student. My sincere thanks to all the members of Museum of Paleontology who provided useful criticism that improved my work. My husband, Anirban Dutta stood by me in good time and in not so good times. I am grateful to my family members who supported me to reach my goal. This work was supported by grants from the Department of Geological Sciences of University of Michigan, Rackham Graduate School of University of Michigan, Conchologists of America, Friday Harbor Laboratory of University of Washington and Geological Society of America. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS…………………………………………………………… ii LIST OF FIGURES…………………………………………………………………….vii LIST OF TABLES………………………………………………………………………xi CHAPTER 1 ...................................................................................................................... 1 INTRODUCTION .......................................................................................................... 1 CHAPTER 2...................................................................................................................... 4 HYDRODYNAMIC EFFECTS OF DRILL HOLES ON POST-MORTEM TRANSPORTATION OF BIVALVE SHELLS ............................................................ 4 Introduction................................................................................................................. 4 Previous studies:..................................................................................................... 5 Conceptual model:.................................................................................................. 6 Materials and methods ................................................................................................ 8 Results.........................................................................................................................9 Discussion................................................................................................................. 10 Comparison of drilled and undrilled shells:......................................................... 10 Potential taphonomic bias in size:........................................................................ 11 Potential taphonomic bias in stereotypy: ............................................................. 12 Implication for an assemblage: ............................................................................ 13 Assessment of biases................................................................................................. 14 Conclusion ................................................................................................................ 16 CHAPTER 3.................................................................................................................... 31 AN EXPERIMENTAL ASSESSMENT OF PENETRATION, EXCAVATION AND CONSUMPTION RATES OF THE MURICID GASTROPOD, NUCELLA LAMELLOSA ................................................................................................................ 31 Introduction............................................................................................................... 31 Boring rate:........................................................................................................... 32 iii Consumption rate: ................................................................................................ 33 Materials and methods .............................................................................................. 33 Experimental design and procedure:.................................................................... 34 Data acquisition: .................................................................................................. 35 Results....................................................................................................................... 36 Discussion................................................................................................................. 36 CHAPTER 4.................................................................................................................... 55 DRILLING UNDER THREAT: AN EXPERIMENTAL ASSESSMENT OF DRILLING BEHAVIOR OF NUCELLA LAMELLOSA IN THE PRESENCE OF A PREDATOR ................................................................................................................. 55 Introduction............................................................................................................... 55 Materials ................................................................................................................... 56 Experimental design.................................................................................................. 57 Results....................................................................................................................... 59 Impact on overall drilling frequency:................................................................... 59 Impact on frequency of incomplete drill holes: .................................................... 59 Time and/or size dependence of the incomplete drill holes:................................. 60 Discussion................................................................................................................. 63 Conclusions............................................................................................................... 65 CHAPTER 5.................................................................................................................... 79 EFFECT OF DUROPHAGY ON DRILLING PREDATION: A CASE STUDY OF CENOZOIC MOLLUSCS FROM NORTH AMERICA ............................................. 79 Introduction............................................................................................................... 79 Influence of durophages on drilling predators:.................................................... 81 Materials and methods .............................................................................................. 82 Results....................................................................................................................... 84 Discussion................................................................................................................. 84 Shell Thickness: .................................................................................................... 85 Prey Selectivity: .................................................................................................... 85 Repair scars as proxy of durophage activity:....................................................... 86 iiiv Latitude:................................................................................................................ 86 Implications............................................................................................................... 87 Conclusions............................................................................................................... 89 Appendix................................................................................................................... 89 CHAPTER 6.................................................................................................................. 112 CENOZOIC HISTORY OF DRILLING PREDATION: A MULTI-TAXON APPROACH ............................................................................................................... 112 Introduction............................................................................................................. 112 History of predatory drilling: ............................................................................. 113 Behavior of drilling predators:........................................................................... 113 Materials and methods ............................................................................................ 114 Data: ................................................................................................................... 114 Statistical analysis: ............................................................................................