MORPHOLOGICAL CLADISTIC ANALYSIS OF THE CORDAITEAN CONES AND IM PLICATIONS FOR PLANT LINEAGES A Thesis by JULIAN EDUARDO CORREA Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Chair of Committee, Anne Raymond Committee Members, Thomas Olszewski James Woolley Head of Department, Rick Giardino August 2015 Major Subject: Geology Copyright 2015 Julian Eduardo Correa ABSTRACT The cordaiteans were a group of Carboniferous and Permian woody plants, which thrived in wetlands and terra firma habitats. Cordaitean cones from wetland habitats are exquisitely well preserved and contain a suit of characters that make their fossils prime candidates for cladistic analysis; historically, there are more male cones than female cone. Cordaitean morphological characteristics make this clade a possible precursor lineage of modern conifer and gnetalean lineages. However, the exact relation between fossil seed- plant clades and modern gymnosperm groups remains enigmatic. The resent discovery of a bisexual cordaitean cone calls into question the relationship between cordaiteans, gnetaleans and angiosperms. This study performs three cladistic analyses in order to find the relations of taxa within the cordaitean clade and other early plant lineages using primarily PAUP* and TNT. An analysis of male only cones provides a phylogram for the relations between the cordaitean taxa; the results also suggest a bisexual ancestry for the clade. A second analysis attempted to introduce the morphologically distinct female cones; the results produce a similar strict consensus tree. However, many of the female cones do not pair with their associated male cones identified in ‘whole-plant’ reconstructions of cordaitean lineages. Instead, female cones formed separate lineages. A final analysis incorporated other plant lineages and assigned traits associated with seeds and pollen to both male and female cones. The results support an early bisexual ancestry to the cordaiteans, and suggests that the cordaiteans are a polyphyletic clade, which gave rise to the voltzialean-conifer lineage. Including more fossil taxa lineages may prove useful, as well as establishing other criteria to compare characters to taxa in cladistic analysis. ii ACKNOWLEDGEMENTS Through this endeavor, I could not have completed anything without the continued su pport of Dr. Anne Raymond; thank you so much for everything. I would also extend my deep est gratitude toDr. James Woolley and Dr. Tom Olszewski who helped me properly run progr ams, discuss and interpret my results. Another round of thanks to all my colleagues in Geology and Geophysics who made s ure I never stopped working, including (but not limited to) Jenn Hendricks, Robert Grajeda a nd Jonathan Sneed. Thank you all so much. Lasly, I would like to thank my family. Their encoragment was invaluable in this path and without their help I would not have reached it to begin with. iii TABLE OF CONTENTS Page ABSTRACT .............................................................................................................................. ii ACKNOWLEDGEMENTS ..................................................................................................... iii TABLE OF CONTENTS ......................................................................................................... iv LIST OF FIGURES ................................................................................................................. vi LIST OF TABLES ................................................................................................................. vii INTRODUCTION .....................................................................................................................1 MATERIALS AND METHODS .............................................................................................10 Taxa..............................................................................................................................10 Cordaites ................................................................................................................10 Gothania .................................................................................................................11 Cordaianthus ..........................................................................................................12 Cathayanthus ..........................................................................................................17 The undescribed bisexual cone ....................................................................................17 Callistophytaleans ........................................................................................................18 Thucydialeans ..............................................................................................................19 Gnetaleasns – Welwitschia mirabilis ...........................................................................21 Angiosperms – Archaeofructaceans ............................................................................22 Archaeopteridaceans ....................................................................................................23 Programs and Parameters .............................................................................................26 RESULTS ................................................................................................................................30 Male only results ..........................................................................................................30 Male-female analysis ...................................................................................................32 Plant lineage analysis ...................................................................................................36 Multivariate analysis ....................................................................................................43 DISCUSSION ..........................................................................................................................46 Bootstrap and Bremer suppor values in phylogenetic studies of ancient land plants ..46 Phylogenetic implications of cordaitean lineages ........................................................46 Coding of male and female cones ................................................................................51 Pollen evolution and implications for voltxialean conifer phylogeny ........................52 Flowers and cone bisexuality .......................................................................................54 CONCLUSIONS......................................................................................................................59 iv REFERENCES ........................................................................................................................61 APPENDIX 1 ...........................................................................................................................72 APPENDIX 2 ...........................................................................................................................75 APPENDIX 3 ...........................................................................................................................78 APPENDIX 4 .........................................................................................................................112 APPENDIX 5 .........................................................................................................................121 APPENDIX 6 .........................................................................................................................138 v LIST OF FIGURES Page Figure 1 Cordaitean Morphology...............................................................................................2 Figure 2 Cordaitean Geologic Age Range .................................................................................5 Figure 3 Plant Phylogeny Hypotheses .......................................................................................6 Figure 4 Cordaitean Seed Phylogeny (Hilton, 2003) .................................................................8 Figure 5 Welwitschia ...............................................................................................................22 Figure 6 Male Only Phylogeny ................................................................................................32 Figure 7 Male Female Phylogeny ............................................................................................34 Figure 8 Plant Lineage Phylogeny ...........................................................................................38 Figure 9 Exploratory Phylogeny of Plant Lineages .................................................................40 Figure 10 Synapomorphies of Plant Lineage Phylogeny .........................................................42 Figure 11 Taxa and Character Heat Map .................................................................................45 Figure 12 Plant Phylogeny (Doyle, 2012) ...............................................................................55 vi LIST OF TABLES Page Table 1 Whole Plant Taxa ..........................................................................................................3 Table 2 Funciton of Seeds vs Cones ..........................................................................................9