University of Alberta A new Early Eocene (Lostcabinian) mammal assemblage from the Main Body of the Wasatch Formation, Northern Green River Basin; The Pinnacles, Sweetwater Co., Wyoming by Allison Marie Neumann A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science Earth and Atmospheric Sciences ©Allison Marie Neumann Fall 2013 Edmonton, Alberta Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission. ABSTRACT Taphonomy of fluvially deposited microvertebrates and systematic paleontology of the Pinnacles buttes in the northwest Great Divide Basin is examined. The Pinnacles buttes contain an early Eocene mammal assemblage of over 900 cataloged specimens from several prolific University of Michigan localities. The diverse assemblage is represented by a minimum of 56 species of 30 families. Sedimentology of the Main Body of the Wasatch formation in the basin margin of the Great Divide has not previously been examined. This thesis provides the first detailed descriptions and measurements of these specimens and explores the sedimentological and taphonomical environments in which this diverse assemblage accumulated in. The microvertebrate fossils were collected from chute-modified channel bar deposits at two fossiliforous horizons in the uppermost 40-50 m of the Main Body of the Wasatch Formation. Concentration of fossils to discrete horizons vertically associated with crevasse splays and gravel bed streams suggests that proximal channel facies played a pivotal role in preservation of fossils in this setting. ACKNOWLEDGMENTS This project nucleated from the collaboration of the University of Alberta, Albion College and University of Michigan, for without the dedicated work of so many collectors and sources of funding over several seasons of fieldwork, the collection would have never become as extensive. I owe much gratitude to Shay Cairns, Cheryl Hodgson and Luke McHugh for all their work measuring section and collecting specimens. This project has been funded by Albion College’s Foundation for Undergraduate Research and Creative Activities (FURSCA), Lawrence Taylor Fund for Undergraduate Research, Dr. Bartel’s Langbo Professorship, NSERC Discovery Grant, University of Michigan Museum of Paleontology, Albion College Geology Department and University of Alberta Department of Earth and Atmospheric Sciences. Drs. Zonneveld, Bartels and Gunnell have provided enormous support and guidance over the duration of my undergraduate and graduate education. I am deeply indebted for the all the opportunities, knowledge and fond memories of collecting at South Pass over the past years. I would like to thank Prof. Bill Bartels for providing me with a solid foundation of the concepts of biostratigraphy and sedimentary geology. I would also like to thank Dr. Gregg Gunnell for his excellent work identifying the taxa in this collection, enthusiasm and expertise of vertebrate mammalogy. Most of all, I would like to acknowledge my advisor Dr. JP Zonneveld for providing the opportunities to pursue this research and his unfailing support throughout this project. TABLE OF CONTENTS CHAPTER ONE – INTRODUCTION……………………………………………………………1 TIMESCALES AND BIOCHRONOLOGY………………………………………………………..………..1 BIOSTRATIGRAPHIC FRAMEWORK OF THE EARLY AND MIDDLE EOCENE………………...…..3 WASATCHIAN………………………………………………………………………………….....5 BRIDGERIAN……………………………………………………..……………………….………7 CLIMATIC SETTING IN THE EARLY AND MIDDLE EOCENE…………………………………….….9 EARLY-MIDDLE EOCENE DEPOSITION IN THE GREATER GREEN RIVER BASIN……………...11 WASATCH FORMATION…………………………………………………………………….....13 GREEN RIVER FORMATION……………………………………………………………...……15 PREVIOUS INVESTIGATIONS IN THE NORTHERN GREEN RIVER BASIN………...……16 REFERENCES……………………………………………………………………………………...………19 CHAPTER TWO – THE PINNACLES BUTTES MAMMAL ASSEMBLAGE OF THE UPPER MAIN BODY OF THE WASATCH FORMATION, NORTHERN GREEN RIVER BASIN, SWEETWATER CO., WYOMING INTRODUCTION……………………………………………………………………..……………..……..36 GEOGRAPHIC AND GEOLOGIC SETTING…………………………………………………....………..38 METHODS………………………………………………………………………………………………….40 FOSSIL LOCALITIES……………………………………………………………………………….……..40 SYSTEMATIC PALEONTOLOGY OF THE PINNACLES BUTTES ASSEMBLAGE……………...….42 ARTIODACTYLA…………………………………………………………….…………………..42 CARNIVORA………………………………………………………………………..……………50 CIMOLESTA………………………………………………………………………...……………56 CONDYLARTHRA………………………………………………………………...……………..60 CREODONTA……………………………………………………………………….……………64 LEPTICTIDA……………………………………………………………………….……………..65 ERINACEOMORPHA………………………………………………………………..…………..68 MARSUPIALIA…………………………………………………………………….…………….70 CETE………………………………………………………………………………………………73 PALAEANODONTA……………………………………………………………………....……..74 PANTODONTA…………………………………….…………………………………….………75 PERISSODACTYLA…………………………………..………………………….…….………..78 PLESIADAPIFORMES………………………………….……………………...……….………..83 PRIMATA……………………………………………….………………….…………….……….88 RODENTIA………………………………………………………………………………..…….101 TILLODONTA………………………………………………………………….……………….105 AGE CORRELATION OF THE PINNACLES ASSEMBLAGE……………………….………………..106 FAUNAL CHARACTERISTICS OF THE LATE WASATCHIAN ……….…………………..107 DISCUSSION…………………………………………………………………………………………….108 CONCLUSIONS…………………………………………………………………………….…………….110 REFERENCES…………………………………………………………………………….………………111 CHAPTER THREE - SEDIMENTOLOGY OF THE WASATCH AND GREEN RIVER FORMATIONS AND FLUVIAL REWORKING ON MICROVERTEBRATE BONEBED ASSEMBLAGES, PINNACLES BUTTES, SWEETWATER CO., WY INTRODUCTION…………………………………………………………………………………………….…….128 STUDY AREA………………………………………………………………………...……………………………128 METHODS……………………………………………………………………….…………………………………136 FLUVIAL AND LACUSTRINE FACIES………………………………………………………………….………140 FACIES ASSOCIATIONS………………………………………………………………………….……..144 TAPHONOMY OF PINNACLES VERTEBRATES……………………………………………………………….165 FOSSIL HORIZONS A AND B………………………………………………………….………………..165 ANTHILL SAMPLING…………………………………………………………………………..………..169 COMPARATIVE ABRASION ON SAMPLES FROM PALEOSOL AND CHANNEL LOCALITIES...............................................................................................................................................171 DISCUSSION……………………………………………………………………………………………………….178 CONCLUSIONS……………………………………………………………………………………………………185 REFERENCES………………………………………………………………………………………...…………….186 CHAPTER FOUR – CONCLUSIONS……………………..…………………………………..196 REFERENCES……………………………………………………………………………………...……………….198 APPENDICES APPENDIX A – MORPHOMETRIC AND DESCRIPTIVE DATA A.1 – ARTIODACTYLA ………………………………………………………………………..200 A.1.1 – Bunophorus sp. A.1.2 – Bunophorus sinclairi A.1.3 – Diacodexis sp. A.1.4 - Hexacodus pelodes A.1.5 – Antiacodon vanvaleni A.2 – CARNIVORA……………………………………………………………………..………202 A.2.1 – Vulpavus sp. A.2.2 – Vulpavus australis A.2.3 – Miacis sp. A.2.4 – Miacis latidens A.2.5 – Uintacyon sp. A.2.6 – Viverravus sp. A.2.7 – Didymictis sp. A.3 – CIMOLESTA…………………………………………………………………………...…205 A.3.1 – Apatemys sp. A.3.2 – Didelphodus sp. A.3.3 – Paleosinops cf. P. lutreola A.4 – CONDYLARTHRA ………………………………………………………………………206 A.4.1 – Hyopsodus sp. A.4.2 – Meniscotherium sp. A.5 – CREODONTA …………………………………………………………………...……….211 A.5.1 – Prolimnocyon antiques A.5.2 – Tritemnodon whitiae A.6 – LEPTICTIDA…………………………………………………………………...…………212 A.6.1 – Palaeictops sp. A.6.2 – Prodiacodon sp. A.7 – ERINACEOMORPHA……………………………………………………...……………..213 A.7.1 – Scenopagus sp. A.7.2 – Talpavus sp. A.8 – MARSUPIALIA……………………………………………………………………...……214 A.8.1 – Peratherium sp. A.8.2 – Peradectes sp. A.9 – CETE…………………………………………………………………..…………………..215 A.9.1 – Hapalodectes sp. A.10 – PALAEANODONTA……………………………………………………………………216 A.10.1 – Palaeanodon sp. A.11 – PERISSODACTYLA…………………………………………………………………….216 A.11.1 – Hyracotherium sp. A.11.2 – Orohippus sp. A.11.3 – Lambdotherium popoagicum A.11.4 – Helaletes sp. A.11.5 – Heptodon A.12 – PLESIADAPIFORMES…………………………………………………………………220 A.12.1 – Microsyosps sp. A.12.2 – Microsyops knightensis A.12.3 – Niptomomys sp. A.12.4 – Phenacolemur sp. A.13 – PRIMATA……………………………………………………………………….……….228 A.13.1 – Notharctus sp. A.13.2 – Notharctus venticolus A.13.3 – Copelemur sp. A.13.4 – Cantius sp. A.13.5 – Cantius nunienus A.13.6 – Trogolemur A.13.7 – Artimonius nocerai A.13.8 – Absarokius sp. A.13.9 – Absarokius gazini A.13.10 – Anemorhysis sp. A.13.11 – Anemorhysis sublettensis A.13.12 – Loveina sp. A.13.13 – Loveina zephyri A.14 – RODENTIA……………………………………………………………………………..236 A.14.1 – Sciuravus sp. A.14.2 – Paramys sp. A.14.3 – Microparamys sp. A.15 – TILLODONTIA………………………………………………………………………….237 A.15.1 – Esthonyx acutidens APPENDIX B – MEASURED SECTIONS B.1 – Sections 1001 and 1002……………………………………..……………238 B.2 – Section 1101………………………………………………………...……239 B.3 – Section 1102………………………………………………………..…….240 B.4 – Section 1103………………………………………………………….…..241 B.5 – Section 1104AC………………………………………………….………242 B.6 – Section 1104B…………………………………………..………………..242 B.7 – Section 1105A……………………………………………..……………..243 B.8 – Section