CONTENTS 



Page 



Introduction i 



Acknowledgments 2 



History of investigation 2 



Occurrence and preservation of material 3 



The Badwater fauna 4 



Correlation and age of the fauna 5 



Systematic description of the Mammalia g 



Alarsupialia ? 9 



Didelphidae ? 9 



Lagomorpha 9 



Leporidae 9 



Rodentia 10 



Carnivora 10 



Limnocyonidae 10 



Miacidae 10 



Condylarthra 11 



Hyopsodontidae 11 



Perissodactyla 12 



Equidae 12 



Brontotheriidae 13 



Chalicotheriidac 13 



Helaletidae 16 



Hyracodontidae 23 



Artiodactyla 23 



Dichobunidae 23 



Agriochoeridae 26 



Oromerycidae 30 



Leptomerycidae 30 



References 31 



Explanation of plates 34 



ILLUSTRATIONS 



Plates 



(All plates follow page 35.) 



1. Lagomorph, carnivore, condylarth, and perissodactyls from the Badwater 



upper Eocene. 



2. Perissodactyls from the Dry Creek and Badwater upper Eocene. 



3. Artiodactyls from the Badwater upper Eocene. 



Chart 



Page 



I. Suggested phylogenetic arrangement of North American tapiroids 16 



