NEW EARLY MIOCENE (ARIKAREEAN) ARTIODACTYLS FROM PANAMA, CENTRAL AMERICA By ALDO FERNANDO RINCON A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2011 1 © 2011 Aldo Fernando Rincon 2 To my family and friends 3 ACKNOWLEDGMENTS I thank C. Jaramillo, C. Montes at STRI for all these years of support and advice; to my advisor (J. Bloch) for everything he has done for my professional development; to the additional members of my Research Committee (B. MacFadden, D. Foster and R. Hulbert) for help with anatomical terminology, taxonomic nomenclature and academic suport. J, Bourque at FLMNH, who prepared the specimens in the laboratory, J. Schiebout and S. Ting at the LSU Geology Department and T. Rowe at University of Texas at Austin, for access to relevant research collections; M. Warren at C.A. Pound Human Identification Laboratory (University of Florida) for access to the X ray- equipment; S. Suarez, M. Vallejo, and F. Moreno (STRI) who helped in the collection of the specimens, F. Lihoreau for help with the phylogenetic character-matrix, and C. Manz, L. Oviedo, E. Woodruff, F. Herrera, A. Hastings, and J. Pardo, for reading an earlier version of the manuscripts and making helpful comments for their improvement. I thank the Panama Canal Authority (ACP) for access to relevant fossil sites. I specially thank to P. Haines and J. Jaeger in the Department of Geological Sciences at the University of Florida for all their help during the Graduate Program. This research was supported by UF Research Opportunity Grant; the U.S. National Science Foundation Partnerships in International Research and Education grant 0966884 (OISE, EAR, DRL), EAR 0824299, and EAR 0418042; STRI-Tupper Paleontological Fund; STRI-Panama Canal Authority Fund; and Ricardo Perez Toyota, Panama. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS .................................................................................................. 4 LIST OF FIGURES .......................................................................................................... 8 ABSTRACT ................................................................................................................... 10 CHAPTER 1 INTRODUCTION .................................................................................................... 12 Conventions ............................................................................................................ 14 Institutional Abbreviations ....................................................................................... 15 Geological Setting ................................................................................................... 15 2 FOSSIL CAMELS (CAMELIDAE) FROM THE LAS CASCADAS FOSSIL ASSEMBLAGE ....................................................................................................... 19 Floridatragulinae ..................................................................................................... 19 Systematic Paleontology ......................................................................................... 22 Aguascalientia panamaensis sp. nov. .............................................................. 24 Description ................................................................................................. 26 Discussion and comparisons. .................................................................... 29 Aguascalientia minuta sp. nov. ......................................................................... 32 Description ................................................................................................. 33 Discussion and comparisons. .................................................................... 35 Phylogenetic Analysis ............................................................................................. 36 Discussion .............................................................................................................. 39 3 FOSSIL ANTHRACOTHERES (ANTHRACOTHERIIDAE) FROM THE LAS CASCADAS FOSSIL ASSEMBLAGE ..................................................................... 58 Anthracotheriidae .................................................................................................... 58 Systematic Paleontology ......................................................................................... 61 Arretotherium meridionale sp. nov .................................................................... 62 Description ................................................................................................. 63 Discussion and comparisons. .................................................................... 69 Phylogenetic Analysis ............................................................................................. 70 Discussion .............................................................................................................. 73 4 CONCLUSIONS ..................................................................................................... 83 5 APPENDIX A DENTAL MEASUREMENTS OF FLORIDATRAGULINAE FROM THE LAS CASCADAS FOSSIL ASSEMBLAGE ..................................................................... 85 B DENTAL CHARACTERS USED IN THE PHYLOGENETIC ANALYSIS OF FLORIDATRAGULINAE (CHAPTER 2) .................................................................. 88 C CHARACTER-TAXON MATRIX USED IN PHYLOGENETIC ANALYSES OF FLORIDATRAGULINAE (CHAPTER 2) .................................................................. 89 D DESCRIPTION OF DENTAL CHARACTERS USED IN THE PHYLOGENETIC ANALYSIS OF ANTHRACOTHERIIDAE (CHAPTER 3) ......................................... 90 E CHARACTER-TAXON MATRIX USED IN THE PHYLOGENETIC ANALYSES OF ANTHRACOTHERIIDAE. .................................................................................. 94 LIST OF REFERENCES ............................................................................................... 95 BIOGRAPHICAL SKETCH .......................................................................................... 104 6 LIST OF TABLES Table page 2-1 Summary table of dental measurement (in mm) of A. panamaensis sp. nov from the Las Cascadas Formation. ..................................................................... 54 2-2 Summary table of dental measurement (in mm) on A. minuta sp. nov. .............. 55 2-3 Comparative values of premolar reduction and predicted body mass along Floridatragulinae and the un-named camels from the Buda Local Fauna .......... 56 2-4 Predicted body mass for A. panamaensis sp. nov. ............................................. 57 3-1 Summary table of dental measurements (in mm) of A. meridionale sp. nov from the Las Cascadas Formation. ..................................................................... 82 A-1 Dental measurements (in mm) of A. panamaensis sp. nov. and A. minuta sp. nov. from Las Cascadas Formation, Panama. ................................................... 85 7 LIST OF FIGURES Figure page 1-1 Location and stratigraphic position of camelid fossils from the Gaillard Cut, Panama Canal area. ........................................................................................... 17 1-2 Stratigraphic relationship between the fossil localities associated to the upper part of the Las Cascadas Formation, Lirio Norte, Panama Canal area. ............. 18 2-1 Location and biochronology of the camel-bearing fossil faunas discussed in this study.. .......................................................................................................... 45 2-2 Diagram showing most of the dental cusp nomenclature applied to ermanent and milk dentitions of camels in this study. ......................................................... 46 2-3 Upper dentition of Aguascalientia panamaensis.. ............................................... 47 2-4 Lower dentition of Aguascalientia panamaensis, (Holotype) .............................. 48 2-5 Lower dentition of Aguascalientia panamaensis (Paratypes). ............................ 48 2-6 Detailed photographs of lower anterior teeth of Aguascalientia panamaensis.. 49 2-7 Detailed view of the lower dentition of Aguascalientia panamaensis.. ................ 49 2-8 Comparison of upper molar morphology of Aguascalientia minuta from the Las Cascadas Formation, Panama, and an unidentified camelid from the Buda Local Fauna, Florida.................................................................................. 50 2-9 Lower dentition of Aguascalientia minuta (Holotype). ......................................... 51 2-10 Detailed photographs of lower anterior teeth of Aguascalientia minuta .............. 52 2-11 Bivariate plots of the natural logarithm of the anterior-posterior length versus maximum transverse width for relevant specimens of Floridatragulinae. ........... 52 2-12 Hypothetical phylogenetic relationships of Aguascalientia panamaensis, sp. nov. and A. minuta, sp. nov. within Floridatragulinae based on 12 character matrix. ................................................................................................................. 53 2-13 Comparison of lower dental morphology of Aguascalientia panamaensis from the Las Cascadas Formation, Panama, and an unidentified camelid from the Buda Local Fauna, Florida. ................................................................................ 53 3-1 Location and biochronology of early Miocene bothriodontines discussed in this