284 GEOLOGY. 



all the species were new and more modern in type. The primitive 

 carnivores, the creodonts, had disappeared and their places were taken 

 by true carnivores. These were chiefly of the cat and dog families, 

 with a few mustelines. Three of the short-lived side branches of the 

 odd-toed ungulates had dropped away, the titan othe res, the upland 

 running rhinoceros, and the aquatic rhinoceros, reducing the perisso- 

 dactyls essentially to their three persistent lines, the horse, the tapir, 

 and the lowland rhinoceros. A straggling lophiodont and an occa- 

 sional doubtful form represented the last serious efforts of the odd- 

 toed tribe in side lines. It seems to have found its place by its pre- 

 vious trials, and thereafter developed consistently along its three most 

 successful lines. A similar remark may be made of the even-toed 

 branch from which the anthracotheres, protocerases, xiphodonts 

 (European), csenotheres, and anoplotheres disappeared, and the evolu- 

 tion settled down into the modern lines. The elotheres lingered through 

 the early epoch, and the oreodons through the whole period, being 

 very abundant during the early part. Peccaries and camels flourished, 

 and the rodents were well deployed, including squirrels, beavers, 

 gophers, rabbits, and lemmings. 



The later fauna, the elephants. — In the late Miocene (Loup Fork) 

 the fauna was broader in type. The most notable addition in North 

 America was the proboscidians. It is now practically demonstrated l 

 that the elephant family originated in Africa, migrated later to Eurasia, 

 thence to North America and later to South America. The elephants 

 reached North America in the late Miocene, and South America in the 

 Pliocene. They were first known in Europe in the lowest Miocene (Bur- 

 digalianof France), while primitive proboscidians lived in Egypt at least 

 as early as the Middle Eocene. This confirms the anticipations of Steh- 

 lin, 2 Osborn, 3 and others, that the point of dispersion of the Probos- 

 cidea and some other groups would be found in Africa. The Eocene 

 forms thus far found in Egypt are Moeritherium, Barytherium, Palcco- 

 mastodon, and perhaps Arsinoitheriwn, an aberrant type of doubtful 



1 C. W. Andrews and Hugh J. L. Beadnell, New Mammals from the Upper Eocene 

 of Egypt, Geol. Surv. of Egypt, 1902; C. W. Andrews, Evolution of Proboscidea, 

 Phil. Trans., Roy. Soc. Lond., 1903. 



2 Ueber die Geschichte des Suiden-Gebisses, II. Thiel; Abh. d. Schweiz, Pal. Gesell., 

 Vol. 27, 1900, p. 477. 



3 Correlation between Tertiary Mammal Horizons of Europe and America, Ann. 

 N. Y. Acad. Sci., Vol. XIII, 1900, pp. 1-72. 



