132 



TITANOTHEEES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



is occasionally seen in these alluvial bottoms. Simi- 

 larly, the Sumatran rhinoceros, R. (DicerorJiinus) 

 sumatrensis, also brachyodont, occasionally frequents 

 such a region. Tapirus indicus inhabits this low 

 forest belt in India, and T. terrestris is the common 

 tapir of the forests and lowlands of Brazil and Para- 

 guay. Among extinct forms the chalicotheres 

 {Moropus, etc.) are found here. 



10. Aquatic, river and lalce iorder habitat. — Rivers, 

 bayous, and lakes, frequented especially by aquatic 

 browsing types with limbs adapted to swimming or 

 to aquatic life and the teeth adapted to the softer 

 kinds of food. Here we find the ungulates represented 

 by their partly degenerate and specialized offshoots the 

 sirenians, the Artiodactyla by the common hippopot- 

 amus or the water buffalo of the Philippines. Either 

 the lower river valleys or the rivers themselves were 

 undoubtedly the habitat of the extinct rhinoceroses 

 known as amynodonts; also, possibly, of the Miocene 

 Teleoceras, a short-limbed river-frequenting animal. 

 Among the titanotheres there are evidences of aquatic 

 adaptation in species of the genus Mesatirhinus. 



CONCLUSIONS AS TO HABITATS OF THE TITANOTHERES 



We have no evidence that titanotheres formerly 

 inhabited alpine, high steppe, or low desert regions. 

 Neither the teeth nor the feet predispose us to specu- 

 late upon such a habitat, nor have we any geologic evi- 

 dence of it. There remain to be considered the "moun- 

 tain," the "forest," the "boreal," or north temperate, 

 the "plains," the "river valleys," the "rivers and la- 

 goons." 



The earliest known types of titanotheres, which are 

 subcursorial in limb structure, developed in a partly 

 open and partly forested country, frequenting mead- 

 ows, lower river valleys, and plains that were flooded 

 during certain seasons of the year. There is reason 

 to believe that one of their upper Eocene radiations 

 (MetarJiinus) became amphibious or even aquatic. 

 Some authors (Riggs, 1912.1, p. 36) believe that 

 DolichorMnus , as well as the short-footed Palaeosyops, 

 was semiaquatic. The habits of these animals are 

 more 'fully considered in Chapter V. 



In Oligocene time the titanotheres entered the 

 savanna-like Great Plains region of western North 

 America, which was in part open country, in part 

 country traversed by undulating rivers and by river 

 bottoms bordered with forests. 



In dentition the titanotheres, both in Eocene and 

 Oligocene phyla, are chiefly a browsing family, though 

 they show incipient indications of adaptation to the 

 grazing habit. 



SECTION 4. BIBLIOGRAPHY FOR CHAPTER II 



Ball, John. 



1887.1. Notes of a naturalist in South America, .xiii, 416 

 pp., 1 map, London, 1887. 



Bauer, Clyde Max. 



1916.1. Contributions to the geology and paleontology 

 of San Juan County, N. Mex. — 1, Stratig- 

 raphy of a part of the Chaco River valley: 

 U. S. Gaol. Survey Prof. Paper 98, pp. 271- 

 278, pis. 6^71, Nov. 24, 1916. 



Maps western part of Puerco-Torrejon area and gives short 

 suraraary of the two formations. 



Berby, Edward Wilber. 



1914.1. The Upper Cretaceous and Eocene floras of South 

 Carolina and Georgia: U. S. Geol. Survey 

 Prof. Paper 84, 200 pp., 29 pis., 12 figs., 1914. 



Blanford, W. T. 



1888.1. The fauna of British India, including Ceylon and 

 Burma — Mammalia, 1888-1891. 



BouTWELL, John Mason. 



1907.1. Stratigraphy and structure of the Park City min- 

 ing district, Utah: Jour. Geology, vol. 15, pp. 

 434-458, 1907. 

 Brown, Barnum. 



1914.1. Cretaceous-Eocene correlation in New Mexico, 

 Wyoming, Montana, Alberta: Geol. Soc. 

 America Bull., vol. 25, pp. 355-380, Sept. 15, 

 1914. 



"Through this eastern exposure I have often found it im- 

 possible to establish any definite line of demarcation between 

 the two beds (Fox Hills and Lance)" (p. 3.5S). 



"The insensible gradation from marine through brackish- 

 water into fresh-water sandstones is not confined to the 

 eastern exposures of the 'Lance' on Hell Creek. The same 

 transition is found on the border of the Lance formation on 

 Alkali Creek, Sevenmile Creek, and Robber's Koost, all 

 tributaries of the Cheyenne River in Weston County, 

 Wyo." 



Calvert, William R. 



1910.1. See Stone, Ralph Walter, 1910.1. 



Clark, William Bullock. 



1891.1. Correlation papers — Eocene: U. S. Geol. Survey 

 Bull. 83, 173 pp., 1891. 



Resume of work of various writers. Deposits of Bridger 

 and Washakie Basins considered as one formation. Regards 

 the Puerco as probably of Eocene age (p. 138). Eocene of 

 the Atlantic coast. Gulf States, Pacific coast; historical sketch 

 of the Eocene of the interior. Table showing relative posi- 

 tion of interior Eocene deposits. Extensive bibliography. 



1896.1. The Eocene deposits of the middle Atlantic slope 

 in Delaware, Maryland, and Virginia: U. S. 

 Geol. Survey Bull.' 141, 167, pp., 40 pis., 1896. 



COCKERELL, THEODORE DrU AlISON. 



1906.1. The fossil fauna and flora of the Florissant 

 (Colorado) shales: Colorado Univ. Studies, 

 vol. 3, pp. 157-176, 5 figs., June, 1906. 

 Birds, fishes, insects, mollusks, plants. 

 CoMSTOCK, Theodore Bryant. 



1873.1. On the geology of western Wyoming: Am. Jour. 

 Sci., 3d ser., vol. 6, pp. 426-432, 1873. 

 Bridger classed as upper Miocene. 



Cope, Edward Drinker. 



1872.3. On Bathmodon, an extinct genus of ungulates: 



Am. Philos. Soc. Proc, vol. 12, pp. 417-420, 

 1872. 



Describes the first mammal from this horizon (.Bathmoion) . 



1872.4. On a new genus of Pleurodira from the Eocene of 



Wyoming: Am. Philos. Soc. Proc, vol. 12, 

 pp. 472-477, 1872. 



Gives a detailed account of the fossil-bearing beds along 

 Bear River, near Evanston, Wyo. 



