THE UNIVERSITY OF CHICAGO FORELIMB SHAPE, DISPARITY, AND FUNCTIONAL MORPHOLOGY IN THE DEEP EVOLUTIONARY HISTORY OF SYNAPSIDA A DISSERTATION SUBMITTED TO THE FACULTY OF THE DIVISION OF THE BIOLOGICAL SCIENCES AND THE PRITZKER SCHOOL OF MEDICINE IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY GRADUATE PROGRAM IN INTEGRATIVE BIOLOGY BY JACQUELINE K LUNGMUS CHICAGO, ILLINOIS DECEMBER 2020 To all the animals I’ve called family. You have never failed to fascinate me, inspire me, and love me. It has always been about you. Max (Canis l. familiaris) Shy (Terrapene ornata) Speedy (Terrapene ornata) Augie (Canis l. familiaris) Sonic (Atelerix albiventris) Dahli (Equus f. caballus) Seymour (Canis l. familiaris) Gunther (Canis l. familaris) Juniper (Canis l. familiaris) TABLE OF CONTENTS LIST OF FIGURES ...................................................................................................................... v LIST OF TABLES ...................................................................................................................... vii ACKNOWLEDGMENTS ......................................................................................................... viii ABSTRACT .................................................................................................................................. xi CHAPTER 1 INRODUCTION .................................................................................................... 1 CHAPTER 2 ANTIQUITY OF FORELIMB ECOMORPHOLOGICAL DIVERSITY IN THE MAMMALIAN STEM LINEAGE (SYNAPSIDA) .......................................................... 9 2.1 ABSTRACT ......................................................................................................................... 9 2.2 INTRODUCTION ............................................................................................................. 10 2.3 METHODS ........................................................................................................................ 12 2.3.1 Taxonomic Sampling .................................................................................................... 12 2.3.2 Temporal Sampling ...................................................................................................... 13 2.3.3 Phylogenetic Signal ...................................................................................................... 15 2.3.4 Geometric Morphometrics and Disparity Analysis ...................................................... 19 2.4 RESULTS ........................................................................................................................... 28 2.4.1 Principal Components Analysis .................................................................................... 28 2.4.2 Disparity ....................................................................................................................... 29 2.5 DISCUSSION .................................................................................................................... 32 CHAPTER 3 PHYLOGENY, FUNCTION, AND ECOLOGY IN THE DEEP EVOLUTIONARY HISTORY OF THE MAMMALIAN FORELIMB ............................... 35 3.1 ABSTRACT ....................................................................................................................... 35 3.2 INTRODUCTION ............................................................................................................. 35 3.3 METHODS ........................................................................................................................ 38 3.3.1 Taxonomic Sampling .................................................................................................... 38 3.3.2 Geometric Morphometric Analyses .............................................................................. 39 3.3.3 Phylogenetic Trees ....................................................................................................... 43 3.3.4 Procrustes and Patristic Distances ................................................................................ 47 3.4 RESULTS ........................................................................................................................... 49 3.4.1 Morphospace Occupation ............................................................................................. 49 3.4.2 Phylogenetic Signal, Procrustes Distance, and Patristic Distance ................................ 60 3.5 DISCUSSION .................................................................................................................... 63 3.5.1 Are Extant Synapsids Analogues for Fossil Synapsids? .............................................. 64 3.5.2 Functional Convergence Versus Morphological Convergence .................................... 65 iii 3.5.3 Diversity of Functional Solutions in Synapsida ........................................................... 67 3.6 CONCLUSION .................................................................................................................. 68 CHAPTER 4 MAJOR TRANSITIONS AND MOSAIC EVOLUTION OF THE SYNAPSID FORELIMB ............................................................................................................ 70 4.1 ABSTRACT ....................................................................................................................... 70 4.2 INTRODUCTION ............................................................................................................. 71 4.2.1 Perspectives on Synapsid Forelimb Evolution ............................................................. 73 4.2.2 Phylogenetic Signal and Evolutionary Rate ................................................................. 76 4.3 METHODS ........................................................................................................................ 82 4.3.1 Taxonomic Sample and Geometric Morphometrics ..................................................... 82 4.3.2 Phylogenetic Trees ....................................................................................................... 82 4.3.3 Phylogenetic Signal ...................................................................................................... 86 4.3.4 Evolutionary Rate ......................................................................................................... 87 4.4 RESULTS ........................................................................................................................... 87 4.4.1 Phylogenetic and Morpho-functional Hypotheses ....................................................... 89 4.4.2 Evolutionary Rate Results for the Morpho-functional Hypotheses .............................. 92 4.5 DISCUSSION .................................................................................................................... 94 4.5.1 Morpho-functional Hypotheses .................................................................................... 94 4.5.2 Mosaic Evolution of the Synapsid Forelimb .............................................................. 100 4.6 CONCLUSION ................................................................................................................ 103 REFERENCES .......................................................................................................................... 105 APPENDIX A - Museum abbreviations associated with specimen numbers throughout . 117 APPENDIX B – Specimen numbers, classification, and section of the humerus used for analyses of Chapter 2 ................................................................................................................ 119 APPENDIX C – Extant mammalian sample and ecological categorizations used in Chapter 3................................................................................................................................................... 141 APPENDIX D – Proximal humerus generic sample and occurrence dates used in Chapter 3 and Chapter 4 ............................................................................................................................ 144 APPENDIX E – Distal humerus generic sample and occurrence dates used in Chapter 3 and Chapter 4 ............................................................................................................................ 148 APPENDIX F – Ulna generic sample and occurrence dates used in Chapter 3 and Chapter 4................................................................................................................................................... 152 iv LIST OF FIGURES 1.1 Taxonomic diversity of major vertebrate groups ...................................................................... 1 1.2 Cladogram and morphological examples of Synapsida ............................................................ 2 1.3 Geometric morphometric methodological pipeline .................................................................. 5 2.1 Phylogeny of proximal humeral sample ................................................................................. 18 2.2 Phylogeny of distal humeral sample ....................................................................................... 19 2.3 Contrasting forelimb disparity in the rise of Therapsida ........................................................ 25 2.4 Distal end morphospaces of PC1 through PC4 ....................................................................... 26 2.5 Proximal humeral principal components plots .....................................................................