THE CLARKFORKIAN LAND-MAMMAL AGE AND MAMMALIAN FAUNAL COMPOSITION ACROSS THE PALEOCENE-EOCENE BOUNDARY KENNETH D. ROSE PAPERS ON PALEONTOLOGY-RECENT NUMBERS 15. Cranial Anatomy and Evolution of Early Tertiary Plesiadapidae (Mammalia, Primates) by Philip D. Gingerich 16. Planning Photography of Microfossils by Robert V. Kesling 17. Devonian Strata of the Afton-Onaway Area, Michigan by R. V. Kesling, A. M. Johnson, and H. 0. Sorensen 18. Ostracods of the Middle Devonian Silica Formation (Volumes I and 11) by Robert V. Kesling and Ruth B. Chilman 19. Late Pleistocene Cold-blooded Vertebrate Faunas from the Mid-Continental United States. I. Reptilia; Testudines, Crocodilia. by Robert E. Preston 20. The Maple Block Knoll Reef in the Bush Bay Dolostone (Silurian, Engadine Group), Northern Peninsula of Michigan by Allan M. Johnson, Robert V. Kesling, Richard T. Lilienthal, and Harry 0. Sorensen 21. A Synopsis of Fossil Grasshopper Mice, Genus Onychomys, and their Relationships to Recent Species by Michael D. Carleton and Ralph E. Eshelman 23. Epizoans on the Brachiopod Paraspirifer bownockeri (Stewart) from the Middle Devonian of Ohio by Diana K. Sparks, Richard D. Hoare, and Robert V. Kesling 24. Early Cenozoic Paleontology and Stratigraphy of the Bighorn Basin, Wyoming by Philip D. Gingerich (ed.) and others Museum of Paleontology The University of Michigan Ann Arbor, Michigan 48109 THE CLARKFORKIAN LAND-MAMMAL AGE AND MAMMALIAN FAUNAL COMPOSITION ACROSS THE PALEOCENE-EOCENE BOUNDARY Frontispiece: Badlands at the head of Big Sand Coulee in the Clark's Fork Basin, Wyoming. Photograph taken from the west edge of Polecat Bench looking toward the southwest, with Heart Mountain and the snow covered Absaroka Range in the background. Sedimentary rocks exposed in the foreground are middle and late Clarkforkian in age. THE CLARKFORKIAN LAND-MAMMAL AGE AND MAMMALIAN FAUNAL COMPOSITION ACROSS THE PALEOCENE-EOCENE BOUNDARY KENNETHD. ROSE Department of Cell Biology and Anatomy School of Medicine Johns Hopkins University Baltimore, Maryland 21205 UNIVERSITY OF MICHIGAN PAPERS ON PALEONTOLOGY NO. 26 Papers on Paleontology No. 26 Museum of Paleontology The University of Michigan Ann Arbor, Michigan 48109 Philip D. Gingerich, Director Dedicated to the Memory of PROFESSOR BRYAN PATTERSON 1909 - 1979 October 15, 1981 TABLE OF CONTENTS List of Figures ................................................................................... vi List of Plates .................................................................................... vii List of Tables .................................................................................... vii Abstract .........................................................................................ix I . Introduction ........................... 1 V . Clarkforkian Mammalian Faunas Outside Mensuration ........................ 2 the Clark's Fork Basin ................. 125 Terminology and Abbreviations ....... 2 Bighorn Basin. Wyoming ............ 125 Acknowledgments ................... 3 Bear Creek. Montana ................ 127 Togwotee Pass. Wyoming ............ 129 I1. Physiographic and Geologic Sketch of Hoback Basin. Wyoming ............. 130 the Clark's Fork Basin ................. 5 Buckman Hollow (Green River Basin). Polecat Bench Formation ............ 5 Wyoming ........................... 130 Willwood Formation ................ 6 Bitter Creek (Washakie Basin). Formational and Faunal Boundaries . 8 Wyoming ........................... 131 Occurrence of Fossils ................ 13 Plateau Valley (Piceance Basin). Paleoenvironment ................... 13 Colorado ........................... 132 University of Michigan Clarkforkian Big Bend National Park. Texas ....... 133 Localities ........................... 14 Baja California ..................... 133 Possible Clarkforkian Faunal Correla- tives Outside North America ......... 134 I11 . The Clarkforkian Land-Mammal Age .... 19 VI . Non-Mammalian Biota of the Historical Sketch .................... 19 Clarkforkian .......................... 137 North American Land-Mammal Ages . 20 Flora of the Clarkforkian ............ 137 Problematical Specimens ............. 21 Mollusca ..................... ..... 138 Definition and Characterization of Osteichthyes ........................ 139 the Clarkforkian .................... 24 Amphibia .......................... 139 Zones in the Clarkforkian ............ 27 Reptilia ............................ 139 Age of the Clarkforkian ............. 28 Aves ............................... 140 IV . Systematic Paleontology of Clarkforkian VII . Mammalian Faunal Composition ........ 141 Mammals ............................. 3 1 Introduction ........................ 141 Multituberculata .................... 31 Analysis of Diversity ................ 141 Polyprotodonta ..................... 34 Analysis of Diversity in Fossil Proteutheria ........................ 36 Assemblages ........................ 143 Lipotyphla ......................... 38 Procedure .......................... 144 Dermoptera ........................ 46 Torrejonian Faunas ................. 145 Primates ........................... 5 1 Tiffanian Faunas ..................... 150 Condylarthra ....................... 68 Discussion of Paleocene Quarry Mesonychia ......................... 86 Assemblages ........................ 155 Taeniodonta ........................ 87 Clarkforkian and Wasatchian Faunas . 159 Pantodonta ......................... 88 Discussion of Clarkforkian and Tillodontia ......................... 90 Wasatchian Faunas .................. 165 Dinocerata ......................... 93 Conclusions from Diversity Analysis . 175 Notoungulata ....................... 96 Carnivora .......................... 98 VIII . Summary ............................. 181 Creodonta .......................... 103 Rodentia ........................... 116 Literature Cited .................... ... ..... 183 Palaeanodonta ...................... 122 Plates ...................................... 190 LIST OF FIGURES 1. Map of Clark's Fork Basin. Wyoming ..... 43 . Esthonyx ancylion ........................ 92 2 . Map of University of Michigan fossil 44 . Esthonyx grangeri ....................... 93 vertebrate localities in the Clark's 45 . Arctostylops steini ....................... 96 Fork Basin ............................. 46 . Arctostylops steini ....................... 97 3. Composite stratigraphic sections in the 47 . Didymictis. ?undescribed species ........... 99 Clark's Fork Basin ...................... 48 . Stratigraphic plot of Didymictis ........... 100 4 . Ranges of Clarkforkian mammals ......... 49 . Viverravus acutus ........................ 101 5. Ranges of higher taxa useful in defining 50 . Viverravus politus ....................... 102 the limits of the Clarkforkian ............. 51 . Uintacyon rudis ......................... 104 6 . Late Paleocene and early Eocene faunal 52 . Uintacyon rudis ......................... 104 zones in North America and Europe ...... 53 . Oxyaena aequidens ...................... 106 7 . Multituberculates ........................ 54 . Oxyaena transiens ....................... 107 8. Peradectes cf . chesteri .................... 55 . Oxyaena transiens ....................... 108 9. Palaeoryctes punctatus ................... 56 . Oxyaena platypus ........................ 109 10 . Palaeosinopa sp .......................... 57 . Oxyaena? lichna. sp . nov ................. 110 11. cf . Leptacodon packi ..................... 58 . Oxyaena? lichna. sp . nov ................. 111 12. cf . Plagioctenodon krausae ............... 59 . Dipsalodon churchillorum. sp . nov ......... 112 13. cf . Plagioctenodon krausae ............... 60 . cf . Dipsalodon sp ........................ 112 14. cf . Pontifactor bestiola ................... 61 . Palaeonictis peloria. sp . nov ............... 115 15. Leipsanolestes siegfriedti .................. 62 . Paramys atavus ......................... 117 16. cf . "Diacodon" minutus .................. 63 . Paramys cf . excavatus .................... 119 17. Plagiomene accola. sp . nov ............... 64. Paramys cf . excavatus .................... 119 18. Worlandia inusitata ...................... 65 . Paramys annectens. sp . nov ............... 120 19. Worlandia inusitata ...................... 66 . Palaeanodon ............................ 122 20 . Microsyops simplicidens. sp . nov .......... 67 . Map of Clarkforkian localities in the 21 . Tinimomys graybulliensis ................. Western Interior of North America ........ 126 22 . Plesiadapis dubius ....................... 68 . North Polar stereographic projection 23 . Plesiadapis gingerichi. sp . nov ............. showing early Tertiary routes of faunal 24 . Plesiadapis gingerichi. sp . nov ............. dispersal ................................ 135 25 . Plesiadapis cookei ....................... 69 . Faunal composition at Rock Bench 26 . Chiromyoides potior and C. major ........ Quarry ................................. 145 27 . Carpolestidae ............................ 70 . Faunal composition at Cedar Point 28 . Ignacius graybullianus .................... Quarry ................................. 151 29 . Phenacolemur pagei ...................... 71 . Faunal composition of the early Clark- 30 . Stratigraphic plot of Phenacolemur ........ forkian Plesiadapis gingerichi Zone ........ 172 3 1. Arctocyonidae ........................... 72 . Faunal composition of the middle Clark- 32 . Ectocion osbornianus .................... forkian Plesiadapis cookei Zone ..........