Paleobiogeographic Analyses of Late Ordovician Faunal Migrations: Assessing Regional and Continental Pathways and Mechanisms A thesis presented to the faculty of the College of Arts and Sciences of Ohio University In partial fulfillment of the requirements for the degree Master of Science Adriane R. Lam May 2015 © 2015 Adriane R. Lam. All Rights Reserved. 2 This thesis titled Paleobiogeographic Analyses of Late Ordovician Faunal Migrations: Assessing Regional and Continental Pathways and Mechanisms by ADRIANE R. LAM has been approved for the Department of Geological Sciences and the College of Arts and Sciences by Alycia L. Stigall Associate Professor of Geological Sciences Robert Frank Dean, College of Arts and Sciences 3 ABSTRACT LAM, ADRIANE R., M.S., May 2015, Geological Sciences Paleobiogeographic Analyses of Late Ordovician Faunal Migrations: Assessing Regional and Continental Pathways and Mechanisms Director ofThesis: Alycia L. Stigall Late Ordovician strata of the Cincinnati Basin record an invasion during the Richmondian Age. Competing hypotheses exist in the literature about the origin and dispersal routes used by the invasive taxa. In this thesis, a suite of traditional and novel paleobiogeographic methods are used to (1) identify geographic source regions for the invasive taxa, (2) reconstruct dispersal paths used, and (3) analyze speciation patterns that influenced biogeographic evolution of taxa. Parsimony Analysis of Endemicity (PAE) applied to over 60 genera that participated in the invasion interval for the C1-C5 depositional sequences supported multiple dispersal routes within Laurentia and between Laurentia and Baltica. Larval type for invasive taxa was dominantly planktotrophic or planula larvae; both have high dispersal potential. Phylogenetic biogeographic analyses using parsimony and model-based approaches were applied to ten clades of Middle-Late Ordovician taxa to compare ancestral range reconstructions characterized speciation type and identify dispersal paths. Methods recovered similar patterns, but differed when interpreting speciation mode. Based on these analyses and a review of the literature, Richmondian invaders are determined to include taxa from multiple geographic areas. Local and global oceanic currents and changing tectonic factors, promoted the immigration of taxa with high larval dispersal potential into the Cincinnati basin. 4 DEDICATION To all the teachers, professors, and advisors throughout my student career who have encouraged and shaped me into the scientist I am today, this one’s for you. Terviseks! 5 ACKNOWLEDGMENTS First and foremost, I must thank my advisor, Professor Alycia Stigall, for her insightful discussions, assistance, encouragement, and unwavering support. Not only has she helped strengthen my abilities as a scientist, but she has also instilled a sense of accomplishment and confidence in me as a young woman in the geosciences. Portions of this thesis could not have been possible through the recommendations and guidance of several researchers: Davey Wright for his encouragement working with R, David Bapst for insightful discussion into time-slicing, and Nick Matzke for assistance with BioGeoBEARS. Correlations among basins were greatly assisted by Dr. Stig Bergström. I would also like to thank my Paleo lab comrades who have put up with my complaints, hysterics, and sense of humor while I wrote this thesis: Jennifer Bauer, Michael Hils, Sarah Trubovitz, Wesley Parker, Zoe Zeszut, Mackenzie Glasgow, and Timothy Henderson. In addition, I would like to thank my committee members, Drs. R. Damian Nance, Greg Springer, and Dave Kidder, for assistance during my time at Ohio University. I must also thank my family for understanding that fossils are awesome, and supporting me while I follow my dreams. Last, but certainly not least, I owe a great deal to my fiancé, Jacob Uzel, for standing by me through all of this and being my biggest support system. This project was supported by funds provided by a Paleontological Award from the Dry Dredgers of Cincinnati, Ohio, the Paleontological Society Arthur J. Boucot Award, an Ohio University Geology Alumni Research Grant, and an Ohio University Geology Alumni Research Fellowship. Additional support was provided by a National Science Foundation Grant (EF-1206750, EAR-0922067) to A.L. Stigall. 6 TABLE OF CONTENTS Page Abstract ............................................................................................................................... 3 Dedication ........................................................................................................................... 4 Acknowledgments............................................................................................................... 5 List of Tables ...................................................................................................................... 9 List of Figures ................................................................................................................... 10 Chapter 1: Introduction ..................................................................................................... 13 Chapter 2: Pathways and Mechanisms of Late Ordovician (Katian) Faunal Migrations of Laurentia and Baltica ........................................................................................................ 17 Abstract ......................................................................................................................... 17 Introduction ................................................................................................................... 18 Methods ........................................................................................................................ 19 Parsimony Analysis of Endemicity ........................................................................... 19 Analysis of Larval Type, Paleoceanography, and Paleoclimate ............................... 21 Results and Interpretation ............................................................................................. 22 Larval Type ............................................................................................................... 22 Paleobiogeography .................................................................................................... 22 Paleoceanography and Paleoclimate ......................................................................... 25 Discussion ..................................................................................................................... 26 Chapter 3: Paleobiogeographic Analyses of Middle to Late Ordovician Taxa and Comparison of Analyses Using Parsimony and Maximum-Likelihood Methods ............ 29 Introduction ................................................................................................................... 29 Geologic Setting ........................................................................................................... 32 Methods ........................................................................................................................ 36 Phylogenetic and Species Occurrence Data .............................................................. 37 Temporal and Geographic Framework ..................................................................... 39 Parsimony-based Phylogenetic Biogeographic Analyses ......................................... 41 Bayesian Analyses .................................................................................................... 43 Results ........................................................................................................................... 45 Ancestral Range Reconstructions ............................................................................. 45 7 Speciation Mode Analyses ........................................................................................ 51 Biogeographic Relationships among Areas .............................................................. 54 Area Relationships and Dispersal Patterns ............................................................... 55 Discussion ..................................................................................................................... 71 Comparison of Maximum Likelihood and Parsimony Analyses .............................. 71 Comparison of Speciation Events to Other Time Intervals ...................................... 74 Biotic Influences on Speciation Patterns .................................................................. 75 Paleoceanographic and Tectonic Influences on Species Dispersal ........................... 78 Conclusions ................................................................................................................... 85 Chapter 4: Origin, Pathways, and Mechanisms of the Late Ordovician Richmondian Invasion: A Review........................................................................................................... 87 Introduction ................................................................................................................... 87 Overview of the Richmondian Invasion ....................................................................... 88 A True Invasion or Recurrent Fauna? ....................................................................... 95 Hypotheses of the Geographic Origin and Dispersal Pathways of Invasive Taxa ....... 97 Arctic (Equatorial) Pathway ....................................................................................