Life Histories of Juvenile Woolly Mammoths from Siberia: Stable Isotope and Elemental Analyses of Tooth Dentin
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Life Histories of Juvenile Woolly Mammoths from Siberia: Stable Isotope and Elemental Analyses of Tooth Dentin by Adam Nicholas Rountrey A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Geology) in The University of Michigan 2009 Doctoral Committee: Professor Daniel C. Fisher, Chair Professor Philip D. Gingerich Professor Kyger C. Lohmann Associate Professor Daniel J. Chiego Jr. © Adam Nicholas Rountrey 2009 Acknowledgements I am most grateful to my advisor, Daniel C. Fisher, for his encouragement, dedication, and passion for all things dental and proboscidean. I thank him for his willingness to hear, discuss, and help develop many fledgling ideas over the years. I would also like to thank my other committee members, Philip D. Gingerich, Kyger C. Lohmann, and Daniel J. Chiego Jr., for their thoughtful criticisms, encouragement, and assistance in technical aspects of this work. This research would not have been possible without access to the elephant and mammoth specimens. Robert Allen , Gennady Boeskorov and Pyotr Lazarev (Mammoth Museum, Institute of Applied Ecology of the North, Yakutia, Russian Federation), Bernard Buigues (International Mammoth Committee, Saint Mandé, France), Sergey Grishin (Shemanovsky Museum, Yamalo-Nenets Autonomous Okrug, Russian Federation), Gary Haynes (University of Nevada, Reno), Dick Mol (Natural History Museum Rotterdam, The Netherlands), Alexei Tikhonov (Zoological Institute, Russian Academy of Sciences, Saint Petersburg, Russian Federation), and Sergey Vartanyan (Geographical Institute, Saint Petersburg State University, Russian Federation) donated, collected, or facilitated access to specimens. I thank David Fox, Lora Wingate, James Gleason, and Ted Huston for my education in the arts of isotopic and elemental analysis. I would also like to express my gratitude to Robyn Burnham for providing me with lab space, Shanan Peters for ii introducing me to R, and Scott Beld for assistance with specimen preparation, thin section production, growth increment analysis, and photography. This work benefitted from my discussions with Aaron Wood, Kathlyn Smith, Ross Secord, Miriam Zelditch, Paul Koch, William Sanders, Bruce Wilkinson, Tom Eiting, and Ryan Bebej. I would also like to thank Devapriya Chattopadhyay, Michael D’Emic, Brady Foreman, Takehito (Ike) Ikejiri, G. Alexander Janevski, Megan Ortega, John Whitlock, and Iyad Zalmout for their support and friendship. Funding was provided through grants or fellowships from the Geological Society of America, the Scott Turner Endowment (University of Michigan, Department of Geological Sciences), the Rackham Graduate School (University of Michigan), the National Geographic Society (Expeditions Council 0394-08 to D. Fisher, and Committee for Research and Exploration 8503-08 to D. Fisher), and the National Science Foundation (EAR-0545095 to D. Fisher). Lastly, I would like to thank my loving wife, Melanie, for offering constant support over the past six years, my parents for encouraging me to pursue my interests, and my son, River, for keeping me sane at times when research became consuming. iii Table of Contents Acknowledgements .................................................................................................................................... ii List of Figures ................................................................................................................................................. x List of Tables .............................................................................................................................................. xiii Chapter 1. Introduction .......................................................................................................................................1 References ........................................................................................................................................8 2. The effects of pretreatment method on the δ13C and δ18O of carbonate in modern dentin...................................................................................................9 Introduction ....................................................................................................................................9 Previous Work ......................................................................................................................... 10 Methods and Materials ............................................................................................................. 18 Untreated .................................................................................................................................. 18 NaOCl .......................................................................................................................................... 18 H2O2 ............................................................................................................................................. 19 AACA ........................................................................................................................................... 19 NaOCl + AACA ......................................................................................................................... 19 H2O2 + AACA ............................................................................................................................. 20 pH Measurements ................................................................................................................. 20 Isotope Analysis ...................................................................................................................... 20 Results ............................................................................................................................................. 21 Stable Isotopes ........................................................................................................................ 21 Sample Loss.............................................................................................................................. 23 Sample CO3 Content ............................................................................................................. 23 pH ................................................................................................................................................. 24 Discussion ..................................................................................................................................... 25 iv Open Versus Closed Tubes ................................................................................................. 29 Weight % CO3 .......................................................................................................................... 30 Conclusions .................................................................................................................................. 31 References ..................................................................................................................................... 44 3. Temporal variation in stable isotope and elemental ratios in the tusk of a juvenile African elephant ............................................................................ 47 Introduction ................................................................................................................................. 47 Elephants in Hwange National Park ............................................................................... 49 Stable Isotopes ........................................................................................................................ 51 δ13C .................................................................................................................................... 51 δ15N .................................................................................................................................... 53 δ18O ................................................................................................................................... 55 Elemental Ratios ..................................................................................................................... 56 Mg/Ca ............................................................................................................................... 56 Mn/Ca and Fe/Ca ......................................................................................................... 57 Zn/Ca ................................................................................................................................ 57 Sr/Ca ................................................................................................................................. 58 Ba/Ca ................................................................................................................................ 59 P/Ca and Pb/Ca ............................................................................................................. 59 Materials and Methods ............................................................................................................. 59 Results ............................................................................................................................................. 72 Compositional Data .............................................................................................................. 72 Growth Increments ..............................................................................................................