CONTENTS V 



Chapter II — Continued. Page 

 Section 3 — Continued. 



Continental adaptive radiation of the African antelopes 125 



Adaptive radiation in the feeding habits of antelopes 126 



Causes of variation and polyphyly among quadrupeds 127 



Habits of the rhinoceroses parallel to those of the Oligocene titanotheres 128 



Habits of the existing tapirs parallel to those of the Eocene titanotheres 128 



Vertical geographic range of quadrupeds -- 129 



Vertical geographic range of the titanotheres 129 



Ten chief habitat zones of mammals _ 129 



Conclusions as to habitats of the titanotheres 132 



Section 4. Bibliography for Chapter II 132 



Chapter III. Discovery of the titanotheres and original descriptions of the types 141 



Section 1. History of discovery 141 



The Oligocene titanotheres 141 



The pioneer period: Prout, Owen, Evans, Leidy (1846-1873).-^ 141 



Taxonomic arrangement and comparison 144 



Work of Marsh and Cope (1870-1887) 144 



Summary of Marsh's contributions 145 



Summary of Cope's contributions 146 



Reinterpretation and phylogenetio study (Osborn, 1887-1919) 146 



Study of certain features 146 



Geologic levels and succession of t3'pes (Hatcher, 1886-1893) 147 



First European notice (Toula, 1892) 148 



Distinctions of sex (Osborn and Wortman, 1895) 148 



Monoph3'Ietic interpretation (Osborn, 1896) 148 



Polyphyletic interpretation (Osborn, 1902-1919) 148 



Recent discoveries by Lull, Lambe, and others 149 



The Eocene titanotheres 149 



Pioneer discoveries 149 



Work in the Bridger, Washakie, and Uinta Basins by Leidy, Marsh, Cope, Scott, Osborn, and others 



(1870-1889) 149 



Discovery in Hungary 150 



Princeton and Cope-Wortman expeditions 150 



First systematic and evolutionary revision (Earle, 1889-1891) 150 



American Museum and other explorations of the Eocene basins (1891-1895) 151 



Investigations and explorations made in preparation for the present monograph (1900-1919) 152 



Section 2. Original descriptions of types of Eocene titanotheres 153 



Five rules for determining the names of titanotheres 153 



The genera and species of Eocene titanotheres 155 



Descriptions of the species- 157 



Section 3. Original descriptions of types of Oligocene titanotheres 201 



List of genera and species 201 



Prout's descriptions of a fragmentary lower jaw, the first titano there made known to science 202 



Pomel's genus Menodus, based on Prout's description and figure 204 



Early notices by Leidy and others, 1850-1870 205 



Species described by Marsh and Cope in 1873-1876 209 



First notice of Canadian titanotheres by Cope, 1886 219 



Species described by Scott and Osborn in 1887 219 



Species described by Marsh in 1887 222 



Canadian species described by Cope in 1889 225 



Last five species described by Marsh, 1890-91 227 



Last species described by Cope, 1891 229 



First European Oligocene species, described by Toula, 1892 230 



Species described by Osborn in 1896 and 1902 231 



Species described by Lull in 1905 234 



Species described by Osborn in 1908 235 



Canadian species described by Lambe in 1908 235 



Second European Oligocene species, described by Kiernik, 1913 240 



Final Oligocene species described by Osborn in 1916-1919 241 



Chapter IV. Systematic classification of the titanotheres 243 



Section 1. Phyletic versus Linnaean S3'stem of classification 243 



Neo-Linnaean systematic divisions (zoologic) and evolutionary phyla (paleontologic) 243 



Superfamily names proposed by Osborn (1898) and Hay (1902) 243 



Family names proposed or adopted by Marsh (1873), Flower (1875), Cope (1879-1889), and Osborn (1889) 243 



Subfamily names and phsda proposed by Steinmann and Doderlein (1890), Earle (1892), and Riggs (1912) 245 



Division of the Oligocene titanotheres into four contemporary phyla, Osborn (1902) 245 



Reclassification of the Eocene and Oligocene subfamilies by Osborn (1914) 246 



Species wrongly referred to the titanotheres 246 



Section 2. Classification of the titanotheres adopted in this monograph 247 



