Phylogenetic and Palaeobiogeographical Analysis of Tylosaurinae (Squamata: Mosasauroidea) by Paulina Andrea Jiménez-Huidobro A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Systematics and Evolution Department of Biological Sciences University of Alberta © Paulina Andrea Jiménez-Huidobro, 2016 ABSTRACT Mosasaurs were a successful and diverse group of marine lizard that existed during the Cretaceous Period, spanning a period of geologic time from the Turonian to Maastrichtian. Their fossils are found around the world, although most records are known from the Northern Hemisphere. The Southern Hemisphere record of mosasaurs is poor and incomplete. The mosasaur clade/subfamily Tylosaurinae is characterized by an elongated rostrum, which does not bear teeth. While the genus Tylosaurus is known from hundreds of specimens collected from the Niobrara Formation in Kansas, and now from dozens of specimens from other localities around North America, the alpha taxonomy of the genus has remained confused and poorly diagnosed. This means that very little was understood about the classification and phylogenetic relationships of North American tylosaurine mosasaurs, not to mention global tylosaurine mosasaurs. This problem originated with the historical rivalry between E.D. Cope and O.C. Marsh during the 1800s, and hopefully, in part, it is resolved in the research reported in this thesis. This thesis reports on a reassessment and re-description of specimens both assigned to the Tylosaurinae, and thus that were newly discovered during this research project. The goal was to refine and improve the understanding of the evolution and palaeogeography of the clade. The clade Tylosaurinae was proved as monophyletic, as well as one of the genus: Tylosaurus. The concept of ‘tylosaurine’ changed from a diverse group with three genera and eleven species, to a more limited concept of the group, consisting in two genera and seven species. The geographic and temporal distribution of the two genera, and the subfamily, where established as upper Turonian to lower Maastrichtian of the North i Atlantic Basin for the genus Tylosaurus, while a cosmopolitan distribution, between the middle Santonian and lower Maastrichtian was determined for Taniwhasaurus. The thesis is divided in seven chapters, starting with a general introduction, followed by reassessments and re-descriptions of specific taxa, with a phylogenetic and paleobiological analysis of the Tylosaurinae, and final conclusions regarding the results of the project. ii PREFACE This thesis project was designed by me and my thesis supervisor, Dr. M. Caldwell. Chapter Two of this thesis has been published as P. Jiménez-Huidobro and M. Caldwell. “Reassessment and reassignment of the early Maastrichtian mosasaur Hainosaurus bernardi Dollo, 1885, to Tylosaurus Marsh, 1872,” Journal of Vertebrate Paleontology vol. 36, issue 3, e1096275-12. I was responsible for the data collection, analysis and manuscript composition. M. Caldwell was the supervisory author and was involved with edits, concept formation, manuscript composition, and financial support. Chapter Three has also been published, as P. Jiménez-Huidobro, T. Simões, and M. Caldwell. “Re-characterization of Tylosaurus nepaeolicus (Cope, 1874) and Tylosaurus kansasensis Everhart, 2005: Ontogeny or sympatry?” Cretaceous Research vol. 65, 68–81. I was responsible for data collection and analysis, as well as the manuscript composition. T. Simões assisted with the data collection and contributed to manuscript edits. M. Caldwell was the supervisory author and was involved with concept formation, manuscript composition, edits and financial support. Chapter Four has not been published, although ready for submission. The co- authors include P. Jiménez-Huidobro, M. Caldwell1, I. Paparella, and T. Bullard. T. Bullard and I were responsible for the data collection. The original idea was initiated by T. Bullard. New data were collected by me, I. Paparella and M. Caldwell. I was responsible for the manuscript composition. M. Caldwell was the supervisory author and was involved with concept formation, manuscript composition, edits, and financial support. iii ACKNOWLEDGMENTS This work was carried out between September 2011 and June 2016, at the Department of Biological Sciences, University of Alberta. The completition of this project would not have been possible without the help of many people I would like to thank below. First, I would like to express my sincere gratitude to my advisor Dr. Michael W. Cadwell for the continuous support of my Ph.D. study and related research, for his patience, motivation, and his guidance that helped me through my research and the writing of this thesis. Besides my advisor, I would like to thank the rest of my thesis committee: Dr. Alison Murray and Dr. Robert Holmes for their insightful comments and encouragement through this process. I would like to thank Dr. John Acorn and Dr. David Evans for taking time out from their busy schedules to serve as my external members of my defense committee. My sincere thanks also goes to T. Konishi, who strongly supported me and was always willing to help me. I would like to thank CONICYT Becas-Chile Scholarship, for funding four years of my Ph.D. program. Funding for this research was provided by NSERC Discovery Grant (238458-01), NSERC Accelerator Grant, and Chair’s Research Allowance to M. Caldwell. I would also like to thank the kind and helpful hosts of all collections I visited: N. Bardet from Musée National d’Histoire Naturelle, D. Brinkman from Yale Peabody Museum, A. Cragg and P. Garbes from Kaikoura Museum, S. Chapman, from Museum of Natural History, London, J. Ebersole from McWane Center of Sciences, D. Ehret from iv Alabama Museum of Natural History, A. Folie from Institute Royal des Sciences Naturelles de Belgique, C. Gee from Goldfuss Museum im Institut für Paläontologie, M. Kano from Mikasa Museum, V. Markstrom from Canadian Fossil Discovery Centre, C. Mehling from American Museum of Natural History, D. Miao from Kansas University, F. Novas from Museo de Ciencias Naturales Bernardino Rivadavia, D. Pagnac from South Dakota School of Mines, K. Sakurai from Mukawa Town Hobetsu Museum, A. Schulp from Natuurhistorisch Museum Maastricht, J. Simes from Institute of the Geological and Nuclear Sciences Te Pū Ao, P. Scofield from Canterbury Museum, A. Tennyson from Museum of New Zealand Te Papa Tongarewa, T. Tokaryk from T.rex Discovery Centre, and L. Wilson from Sternberg Museum of Natural History. To my dear friends K. Bramble, I. Paparella, T. Simões and O. Vernygora, thanks for scientific discussions and strong friendship and support. I would also like to thank all my fellow grad students from the Paleontology Lab at the University of Alberta for stimulation, advice and suggestions, and for providing a great friendly environment. Finally, I would like to thank my family, my parents, sister and brother, sister in law, brother in law, and nieces for their patience, love and support from the far South. I could not make it without them. Thank you. v TABLE OF CONTENTS Abstract…………………………………………………………………………………… i Preface………………………………………………………………………………...… iii Acknowledgments………………………………………………………………………. iv Table of Contents…………………………………………………………………….….. vi List of Tables……………………………………………………………………...……... x List of Figures………………………………………………………………...…………. xi Anatomical Abbreviations…………………………………………………………...… xiv Institutional Abbreviations………………………………………………………….… xvii CHAPTER ONE: General Introduction………………………………………………...... 1 Organization of Chapters………………..……………………………………….. 9 Literature Cited…………………………………………………………………. 12 CHAPTER TWO: Reassessment and reassignment of the early Maastrichtian mosasaur Hainosaurus bernardi Dollo, 1885 to Tylosaurus Marsh, 1872………………………... 32 Abstract…………………………………………………………………………. 33 Introduction……………………………………………………………………... 34 Materials and Methods……………………………………………………...…... 37 Systematic Palaeontology………………………………………………………. 38 Descriptions…………………………………………………………………….. 40 Phylogenetic Analysis…………………………………………………………... 51 Discussion……………………………………………………………….……… 52 Conclusions……………………………………………………………………... 57 vi Literature Cited……………………………………………………………….… 59 CHAPTER THREE: Re-characterization of Tylosaurus nepaeolicus (Cope, 1874) and Tylosaurus kansasensis Everhart, 2005: Ontogeny or Sympatry?................................... 80 Abstract……………………………………………………………………….… 81 Introduction……………………………………………………………….…….. 82 Geological Settings………………………………………………………….….. 85 Materials and Methods………………………………………………………….. 86 Systematic Palaeontology………………………………………………………. 87 Descriptions…………………………………………………………………….. 88 Discussion……………………………………………………...……………… 106 Phylogenetic Analysis……………………………………...……………..…… 110 Conclusions………………………………………………………………….… 112 Literature Cited………………………………………………………………... 114 CHAPTER FOUR: A new species of tylosaurine mosasaur from the upper Campanian Bearpaw Formation of Saskatchewan, Canada……………........................................... 130 Abstract………………………………………………..……….……………… 131 Introduction……………………………………………...…………………….. 132 Geological Settings…………………………………………………...…….…. 133 Materials and Methods……………………………………………………….... 134 Systematic Palaeontology…………………………………………………..…. 135 Descriptions……………………………………………………..…………….. 137 Phylogenetic Analysis……………………………………...……………..…… 151 Discussion……………………………………………………...……………… 152 vii Conclusions………………………………………………………………….… 155 Literature Cited………………………………………………………………..