Evolution of the Caudal Vertebral Series in Macronarian Sauropod Dinosaurs: Morphofunctional and Phylogenetic Implications A Thesis Submitted to the Faculty of Drexel University By Lucio Manuel Ibiricu In partial fulfillment of the Requirements for the degree of Doctor of Philosophy October 2010 © Copyright 2010 Lucio Manuel Ibiricu. All Rights Reserved ii DEDICATION To the people who trusted me and my grandfather (Manolo) iii ACKNOWLEDGMENTS First of all, I want to thank my advisor, Dr. Lacovara, for several things: for admitting me in the program, for supporting me constantly, especially at the beginning of my experience in the United States and for exposing me to ―big‖ people in Paleontology. Ken gave me the opportunity to work and learn; I will always be grateful to him. I also thank Dr. Spotila, the head of my committee, for always supporting me and for helping in the organization, always very important during the PhD. I really appreciate it. In addition, I want to thank Dr. Dodson for accepting to be part of my committee. His presence is a privilege to me and it is an honor to say that he was part of my PhD committee. I would like to express my gratitude to Dr. Gallagher. He taught me the majority of my first courses at Drexel and I always learned a lot from him. Also, my first TA was under his supervision; therefore, I want to thank him for all the support he gave me both as student and as a TA. Likewise, I would like to thank Dr. Kilham, because her presence in my committee pushed me to learn more about ecology, which helped me integrate dinosaurs and their environment. I want to express special gratitude to the last member of my committee, Dr. Lamanna. We met several years ago in Patagonia. I had the opportunity to share several field seasons with him. Since that moment to the present, Matt taught me how be a better Paleontologist and he will always be a model for me, many thank for all your help. I would like to thank Dr. Harris for his extremely helpful comments in manuscripts. Every time he answers one of my questions I learn more than reading a book. iv I am indebted to Jason Poole, not just for drawing many of the figures, but also for something more important, his friendship. I would like to thank Dr. Coughenour (Chris) for being a very good lab- mate during my first four years at Drexel. I also thank Marcelo (in addition to me, the ―male‖ side of the group), Bibi and Eugenia. They are those people everyone needs after a long day of work, gracias, grazie and obrigado. I want to say thanks to the Paleo-Lab (Jason, Elena, who reviewed the grammar of one of my chapters, Victoria and Paul). Also, I am indebted to different people who helped me in different aspects of my Thesis, such us Dr. Schachner, Evan, and Alison. I am also very grateful to Jean Lacovara because she was always there for anything I needed. I am also indebted to several people of the Department of Biology (Susan Cole, Dr. Duwel, Brenda, Matt McDonald and the head of the department, Dr. Twiss and Dr. Howett). Also, I want to thank the Office of Graduate Studies, particularly Dr. Lee for funding (Grad-Student Grant) during four months. I would like to express my gratitude to all these people for allowing me to review original materials: Dr. Salgado (Universidad Nacional del omahue, Neuqu n), r. Gonz lez- Riga ( RI YT, Mendoza), I. erda (Museo inco Saltos), J. Porfiri and R. Ju rez ( entro Paleontol gico Lago Barreales), . Mu oz (Museo Provincial arlos meghino), Retamal (Rinc n de los Sauces), and r. Henrici ( arnegie Museum). Moreover, I would like to say thanks to all the people of the Museo Provincial ―Padre Manuel Jes s Molina‖ in R o Gallegos, Argentina. v I am also indebted to my friends from omodoro (Paleo-Lab): Rub n, Gabriel, Marcelo, and Edmundo. Thanks to them I started to work in Paleontology. I really hope to continue working with them for many more years. They taught me what a ―Paleontology team‖ actually means. I will always be grateful to them. I would like to thank all my alafate‘s friends for helping and for making me feel at home, especially to Gerardo Povazsan and his family. They always had mate when I really needed one. lso to my life friends: ar o, Manolo, Damian, Laura, and Cristian. i u i (Leticia), mis hermanos (Marcela, Gaby, Diego y Taty) y a mis 14 sobrinos y sobrinas. Sin ellos nada de esto y muchas otras cosas más serían posibles. También a toda la familia de Gabriela, gracias por todo. Finally, to my wife (Gabriela), we embarked on this challenge together and we finished it together, as it will be for the rest of our lives. vi LIST OF CONTENTS LIST OFTABLES………………………………………………………………………...X LIST OF FIGURES……………………………………………………………………XIV ABSTRACT……………………………………………………………………………..XI General Introduction………………………………………………………………………1 CHAPTER 1: An overview of the caudal vertebrae sequence of macronarian sauropod dinosaurs…………………………………………………………………………………..8 INTRO U TION……………………………………………………………………….. 8 Camarasauromorpha………………………………………………………………...10 Brachiosauridae……………………………………………………………………..18 ―Basal Titanosauriformes‖………………………………………………………….23 ― erived Titanosauriformes‖……………………………………………………….26 Somphospondyli……………………………………………………………………36 Titanosauria…………………………………………………………………………41 Brazilian titanosaurian sauropods…………………………………………………..67 COMPARISON…………………………………………………………………………73 vii DISCUSSION………………………………………………………………………. …..76 CONCLUSIONS………………………………………………………………………...89 CHAPTER 2: A parsimony analysis of caudal skeletal evolution in Macronaria (Dinosauria: Sauropoda)…………………………………………………………………98 ABSTRACT……………………………………………………………………………...98 INTRODU TION……………………………………………………………………….99 MATERIALS AND METHODS……………………………………………………….101 COMPARISON AND DESCRIPTION………………………………………………...102 DISCUSSION…………………………………………………………………………..125 CHAPTER 3: Caudal osteology of a gigantic titanosaurian (Sauropoda: Macronaria) from the Upper Cretaceous Pari Aike Formation of southern Patagonia………………168 ABSTRACT……………………………………………………………………………168 INTRODU TION……………………………………………………………………..169 MATERIALS AN METHO S………………………………………………………172 DESCRIPTION………………………………………………………………………...174 COMPARISONS……………………………………………………………………….181 DISCUSSION………………………………………………………………………….188 CONCLUSIONS……………………………………………………………………….200 viii CHAPTER 4: The influence of soft tissues on the titanosaurian caudal vertebrae: morphofunctional and phylogenetic implications………………………………………241 ABSTRACT…………………………………………………………………………....241 INTRODU TION……………………………………………………………………..242 MATERIALS AN METHO S……………………………………………………....244 DES RIPTION………………………………………………………………………...250 RESULTS………………………………………………………………………………257 DISCUSSION………………………………………………………………………….260 CONCLUSIONS……………………………………………………………………….271 CHAPTER 5: The southernmost records of Rebbachisauridae (Sauropoda: Diplodocoidea), from the early Late Cretaceous of central Patagonia…………………282 ABSTRACT……………………………………………………………………………282 INTRODUCTION……………………………………………………………………...283 MATERI LS…………………………………………………………………………...287 DESCRIPTION………………………………………………………………………...288 COMPARISON………………………………………………………………………...296 IS USSION…………………………………………………………………………..304 General Conclusions……………………………………………………………………323 ix LIST OF REFEREN ES……………………………………………………………….328 LIST OF APPENDI ES………………………………………………………………..361 VIT ……………………………………………………………………………………362 x LIST OF TABLES Table 1.1: Phylogenetic definitions for Macronaria subclades (excluding Titanosauria and its subclades)………………………………………………………………………...90 Table 1.2: Phylogenetic definitions for Titanosauria and its subclades. Node- based definitions are in boldface type, stem- based definitions are in regular type……………91 Table 1.3: Articular caudal surfaces definitions (modified from Tidwell et al., 2001)…93 Table 2.1: Macronarian sauropods (excluding titanosaurids), caudal materials and reporting authors. (*) Asterisk, indicates the taxa included in this study. Abbreviations: D, Distal caudals; M, Middle caudals; P, Proximal caudals; ND, not described………141 Table 2.2: Titanosaurian taxa, caudal material preserved and reporting authors. bbreviations, as table 1………………………………………………………………..142 Table 2.3: Macronarian sauropods (excluding titanosaurids). Age, Formation and Country (*) indicates the included in this study………………………………………..144 Table 2.4: Titanosaurian taxa, age, horizon, and country……………………………...145 Table2. 5: Macronarian clades, example taxa and morphological caudal features…….146 Table 2.6: Titanosauria subclades, example taxa and morphological caudal features. In bold are the characters cladistically supported in this analysis as well as in previus phylogenetic analyses…………………………………………………………………..149 xi Table 2.7: Proximal, middle, distal caudal centra articulations of some macronarian sauropods. Abbreviations: M; moderately developed, S; strongly developed; 0; flat, 1; concave, 2; convex (modified from Tidwell et al. 2001 and Gonz lez Riga et al. 2008)……………………………………………………………………………………154 Table 2.8: Character Optimization criterion ACCTRAN (Accelerated transformation). Abbreviations: Nodes; B-Lith, basal lithostrotian; B-Sh, basal somphospondylian; Bt, basal Titanosauriformes; D-Sh, derived somphospondylian; D-Tf, derived Titanosauriformes, Mdt, more derived titanosaurus; Taxon; Ad, Adamantisaurus; Aeo, Aeolosaurus; Bau, Baurutitan, Pell, Pellegrinisaurus; Rc, Rinconsaurus; Tr, Trigonosaurus. I, consistency index………………………………………………….157 Table 2.9: Character Optimizatin DELTRAN (Delayed transformation). Abbrevations as Table 2.8………………………………………………………………………………..158 Table 3.1: Titanosaurian taxa, age, horizon, and country. (*), indicate