EOCENE AND OLIGOGENE TITANOTHERES OF MONGOLIA 



By Henry Fairfield Osborn 



The Eocene and Oligocene titanotheres of Mongolia, 

 discovered in the years 1922 and 1923, after the manu- 

 script of this monograph had been completed and 

 sent to the Geological Survey, are described and 

 figured in this appendix. The outstanding features 

 of the Tertiary formations in which they occur are 

 also described and figured. The appendix closes with 

 a special bibliography relating to the Tertiary of 

 Mongolia and its fauna, so far as it had been described 

 up to the end of the year 1925. 



HISTORY OF THEORY AND OF EXPLORATION 



ASIATIC CENTERS OF ORIGIN OF MAMMALS 



The third Asiatic expedition of the American 

 Museum of Natural History started in 1921 to pre- 

 pare for its exploration of the Gobi Desert of Mongolia 

 and to test the theory advanced in the year 1900 by 

 the writer of the present monograph that the high 

 plateau region of central Asia would prove to be the 

 arena of the evolution and adaptive radiation of 13 of 

 the principal orders of mammals. This theory was 

 set forth by the writer before the New York Academy 

 of Sciences in two presidential addresses in the years 

 1899 and 1900 '^ and was graphically illustrated by 

 a world chart (fig. 761) on which the names of 21 

 orders of placental mammals were printed, together 

 with the places of their origin and distribution accord- 

 ing to this theory. 



In the text and figures of these addresses the chief 

 continental centers of origin of these orders of mam- 

 mals appeared as follows: 



Africa: 



Proboscidea (elephants and mastodonts) . 



H3'racoidea (rock conies). 



Sirenia (manatees and dugongs) . 

 Madagascar: 



Lemuroidea (lemurs). 

 Oceania : 



Cetacea : 



Archaeoceti (primitive whales) . 

 Mystacoceti (wha/lebone whales). 

 Odontoceti (toothed whales). 

 Central Asia: 



Insectivora (insectivores) . 



Cheiroptera (bats). 



Creodonta (primitive carnivores). 



Garni vora (modern carnivores). 



Tillodontia (tillodonts) . 



Rodentia (rodents). 



Taeniodonta (primitive edentates) . 



«• Osborn, H. F., Science, April, 1900, p. 567. 



Central Asia — Continued. 



Primates (Mesodonta). 



Amblj'poda (Coryphodon and Dinoceras). 



Condylarthra (condylarth ungulates). 



Perissodactyla (odd-toed ungulates). 



Ancylopoda (clawed perissodactyls) . 



Artiodactyla (even-toed ungulates) . 

 India: 



Anthropoidea (primates) . 

 South America: 



Edentata (edentates). 



Litopterna (cursorial ungulates) . 



Toxodontia (toxodont ungulates) . 



Tj'potheria (typotheres) . 



Osborn (1900.187, pp. 55, 56) observed: 



Until the Pleistocene, northern Asia is unknown paleon- 

 tologically — here is a region for explorers; we may consider it 

 as part of a broad Eurasiatic land area extending from the 

 Rocky Mountain region to Great Britain. Every year's dis- 

 covery increases the resemblances and diminishes the differ- 

 ences between Europe and the Rocky Mountain region. In 

 the absence of all knowledge of Asia, we find the pure or autoch- 

 thonous fauna of the holarctic region distributed in western 

 Europe and in western North America. 



C. W. Andrews (Osborn, 1901-1923) says: 



The above chart of 1900 has been verified by the discovery 

 (1901-1904) of numerous ancestors of the orders Sirenia, 

 Proboscidea, Hyracoidea, Primates, and Archaeoceti in North 

 Africa; more recently (1922, 1923) in central Asia by the dis- 

 covery of members of the orders Insectivora, Tillodontia, 

 Carnivora, Rodentia, Ambl3'poda, Perissodactyla, Ancylopoda, 

 and Artiodactyla. 



Osborn, in 1925, added: "Charles W. Andrews's 

 discoveries (1901-1904) demonstrate that the primi- 

 tive whales (Archaeoceti) originated in northern 

 Africa. Osborn is now inclined to place the origin of 

 the Anthropoidea (Primates) in central Asia." 



EXPLORATIONS IN MONGOLIA 



During the seasons of 1922 and 1923 the third 

 Asiatic expedition, under the leadership of Roy Chap- 

 man Andrews, discovered 10 geologic formations of 

 Tertiary age, which contained altogether a very large 

 number of fossil mammals. Part of the territory 

 Andrews explored in 1922 had been crossed by Raphael 

 Pumpelly in 1862-1865; by Obruchev in 1892-1894, 

 who applied the name "Gobi series" to the later sedi- 

 ments; and by Chernov in 1908. Similar territory 

 farther south had been crossed by Von Richthofen in 

 1877, and it was he who gave the name Khan-Khai 

 beds to the Tertiary sediments he found in the desert 

 region. The underlying series as developed in China, 



