CONTENTS 



Page 



Introduction i 



Acknowledgments 2 



History of investigation 2 



Occurrence and preservation of material 3 



The Bison basin faunas 4 



Environment and relationships between the Bison basin faunas 7 



Age and correlation of the faunas lo 



Systematic description of vertebrate remains I2 



Reptilia 12 



Sauria 12 



Anguidae 12 



Mammalia 12 



Multitubcrculata 12 



Ptilodontidae 12 



Marsupialia 14 



Didelphidae 14 



Insectivora 15 



Leptictidae 15 



Pantolestidae 17 



Primates 19 



Plesiadapidae 19 



Carnivora 25 



Arctocyonidae 25 



Mesonychidae 35 



Miacidae 35 



Condylarthra 36 



Hyopsodontidae 36 



Phenacodontidae 42 



Pantodonta 47 



Coryphodontidae 47 



References 51 



Explanation of plates 54 



