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For more information, please contact [email protected] FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES PALEOENVIRONMENTS AND PALEOECOLOGIES OF CENOZOIC MAMMALS FROM WESTERN CHINA BASED ON STABLE CARBON AND OXYGEN ISOTOPES By DANA MICHELLE BIASATTI A Dissertation submitted to the Department of Geological Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy Degree Awarded: Spring Semester, 2009 The members of the Committee approve the Dissertation of Dana Michelle Biasatti defended on February 16, 2009. _____________________________________ Yang Wang Professor Directing Dissertation _____________________________________ Gregory Erickson Outside Committee Member _____________________________________ Leroy Odom Committee Member _____________________________________ Vincent Salters Committee Member Approved: _____________________________________ Leroy Odom, Chair, Department of Geological Sciences The Graduate School has verified and approved the above named committee members. ii To my family. iii ACKNOWLEDGEMENTS I would like to extend special thanks to my supervisor, Dr. Yang Wang, for her advice, encouragement, and financial support throughout this project. I am extremely grateful to Dr. Wang for the research opportunities I have been granted throughout my time at Florida State University. I also thank Dr. Wang for her constructive reviews of this work. This research was funded by the U.S. National Science Foundation (INT-0204923 and EAR-0716235 to Yang Wang). I would also like to thank the Florida State University Department of Geological Sciences and the National High Magnetic Field Laboratory Geochemistry Division for supporting this research. In particular, I would like to thank Dr. Leroy Odom and Dr. Neil Lundberg of Florida State University for finding continuous financial support for me. Furthermore, I thank the FSU Foundation and the Congress of Graduate Students for providing financial support. In addition, I am grateful to Dr. Gregory Erickson, Dr. Leroy Odom, and Dr. Vincent Salters for serving on my advisory committee. I thank Dr. Yingfeng Xu of Florida State University and Dr. Jason Curtis of University of Florida for assistance with sample analyses and Ted Zateslo and Dr. Michael Bizimis of Florida State University for technical assistance in the lab. I would like to thank Dr. Tao Deng of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, China, and the Hezheng Museum of Natural History in Hezheng County, Gansu Province, China, and Dr. Feng Gao of the Yunnan Institute of Cultural Relics and Archaeology in Kunming, Yunnan Province, China, for their generous contributions of fossil specimens and literature for this research and for invaluable assistance in the field. I am grateful Dr. Bruce MacFadden of University of Florida and Dr. Lawrence Flynn of Harvard University for assistance in the field and helpful discussions on the specimens. Furthermore, I thank Mabry Gaboardi of Florida State University for helpful discussions and assistance in the lab. Finally, I thank Dr. Louis Jacobs and Dr. Crayton Yapp of Southern Methodist University, who, as my Master’s Thesis advisors, encouraged and inspired me to step beyond the traditional field of paleontology into the world of paleobiogeochemistry. iv TABLE OF CONTENTS List of Tables ............................................................................................................ vii List of Figures ........................................................................................................... viii Abstract ..................................................................................................................... xi 1. INTRODUCTION ................................................................................................. 1 2. MEASUREMENT OF STABLE ISOTOPES OF CARBON AND OXYGEN AS A TOOL FOR PALEOECOLOGICAL AND PALEOCLIMATOLOGICAL RECONSTRUCTION ......................................... 4 2.1. Preservation of Stable Isotopic Composition in Tooth Enamel ......... 4 2.2. Carbon Isotopes in Paleodiet and Paleoecological Studies ............... 4 2.3. Oxygen Isotopes in Paleoclimate Studies .......................................... 9 3. STRENGTHENING OF THE EAST ASIAN SUMMER MONSOON REVEALED BY A MARKED SHIFT IN SEASONAL PATTERNS IN DIET AND CLIMATE AFTER 2-3 MA IN NORTHWEST CHINA .................. 13 3.1. Introduction ....................................................................................... 13 3.2. Study Site .......................................................................................... 15 3.3. Materials and Methods ....................................................................... 15 3.3.1. Sample Materials ............................................................. 15 3.3.2. Experimental Methods ..................................................... 18 3.4. Results and Discussion ...................................................................... 21 3.4.1. Assessment of Fossil Tooth Preservation ........................ 21 3.4.2. 25 Million Years of Climate Variability in the Linxia Basin ..................................................................... 25 3.4.3. Changes in Seasonality and Monsoon Strength ............... 34 3.5. Conclusions ........................................................................................ 48 4. PALEOECOLOGY OF CENOZOIC RHINOS FROM NORTHWEST CHINA: A STABLE ISOTOPE PERSPECTIVE ................................................ 52 4.1. Introduction ........................................................................................ 52 4.2. Study Site ........................................................................................... 54 4.3. Materials and Methods ...................................................................... 56 4.3.1. Sample Materials ............................................................. 56 4.3.2. Laboratory Methods ......................................................... 61 4.4. Results and Discussion ...................................................................... 63 4.4.1. Late Oligocene Rhinoceroses .......................................... 63 v 4.4.2. Middle Miocene Rhinoceroses ........................................ 73 4.4.3. Late Miocene Rhinoceroses ............................................ 76 4.4.4. Pliocene Rhinoceroses ..................................................... 86 4.5. Conclusions ........................................................................................ 87 5. PALEOECOLOGIES AND PALEOCLIMATES OF CENOZOIC MAMMALS FROM YUNNAN PROVINCE, CHINA, BASED ON STABLE CARBON AND OXYGEN ISOTOPES .............................................. 89 5.1. Introduction ....................................................................................... 89 5.2. Study Site ........................................................................................... 90 5.3. Materials and Methods ....................................................................... 97 5.3.1. Sample Materials ............................................................. 97 5.3.2. Laboratory Methods ......................................................... 98 5.4. Results and Discussion ...................................................................... 100 5.4.1. Assessment of Fossil Tooth Preservation ........................ 100 5.4.2. Carbon Isotope Compositions of Fossil Mammals from Six Localities in Yunnan ......................................... 100 5.4.3. Oxygen Isotope Compositions of Fossil Mammals from Six Localities in Yunnan ......................................... 109 5.5. Conclusions ........................................................................................ 114 6. CONCLUSION ..................................................................................................... 117 APPENDIX A: Data from Analyses of Bulk Carbonate Samples ............................. 122 APPENDIX B: Data from Analyses of Serial Carbonate Samples ........................... 130 APPENDIX C: Data from Analyses of Organic Samples ......................................... 143 APPENDIX D: Data from Analyses of Phosphate Samples ..................................... 145 APPENDIX E: Details of Experimental Methods ..................................................... 146 REFERENCES .......................................................................................................... 150 BIOGRAPHICAL SKETCH ..................................................................................... 167 vi LIST OF TABLES Table 3.1: Statistical significance of differences in mean oxygen isotopic compositions of various taxa at different ages as determined by two-tailed t-tests .................................................................................. 27 Table 3.2: Carbon isotope compositions of plants from the Linxia Basin ................ 49 Table 4.1: Lithology and paleontology of the Linxia Basin stratigraphic sequence ................................................................................................... 58 Table 4.2: Statistical significance of differences in mean carbon and oxygen isotopic compositions of