THE MIOCENE OF EUROPE, ASIA, AND NORTH AMERICA 253 



Characteristic 

 Lower Miocene 

 Mammals 

 Anthropoid apes 



(gibbons) 

 Mastodons 

 Dinotheres 

 Anchitheres 

 Tapirs 

 Hhinoeeroses 



Teleocerine 



Dicerorhine 



Aceratherine 



?Diceratherine 

 Chalicotheres 

 Suillines 



Horned cervulines 

 Tragulids, or chevrotains 

 Antelopes 



(first Cavicornia) 

 Anthracotheres 



{Brachyodus only) 

 Amphicj^ons 

 Dinocyons 

 . Sirenians 



Of the artiodactyls, beside the surviving 

 anthracothcre Brachyodus, we observe the 

 pigs, recently monographed by Stehlin.^ In 

 the early Miocene he notes (p. 481) that the 

 descendants of the Upper Oligocene Palceo- 

 chcerus are becoming more sharply differen- 

 tiated, the larger ones being gradually trans- 

 formed into Hyotherium sommeringi of the 

 Miocene. There also appear two new invading 

 forms (Listriodon and C hcerotheriwn) , of remote 

 relationship to the local suillines. Thus, like 

 the rest of the mammals, the Suidae are en- 

 riched by the arrival of new types at this time. 

 "The faunal change," continues this writer 

 (p. 482), "is perhaps the grandest that oc- 

 curred in Europe during the entire Tertiary; 

 no doubt it followed some far-reaching geo- 

 logical change ; presumably communication 

 was reestablished with some great evolutionary 

 center of the Old World." 



The true selenodont artiodactyls are also 

 reenforced by two fresh arrivals. Among the 

 tragulids, a type closely related to the water 

 chevrotains of western Africa {H ycemoschus) 

 now appears for the first time. The true 



modern tragulids (Tragulidse) are a very 

 primitive group of small ungulates, embracing two living genera, the Indian 

 and Himalayan mouse-deer, or chevrotains {Tragulus), and the West Afri- 

 can water-chevrotains (Hycemoschus) ; Tragulus scarcely exceeds a rabbit 

 in size; it suggests an agouti with unusually long legs, while the larger 

 members of the family show some analogy to the musk deer. 



Similarly the pro-Cervidce are enriched by the appearance of horned 

 cervulines {Dicrocerus), notable as the first horned artiodactyls to enter 

 Europe, and closely similar to the existing muntjacs. A new cervuline, 

 Micromeryx, also arrives, probably from Asia. 



Marking a still wider ])reak from the Oligocene selenodonts is the re- 

 ported occurrence (Stehlin) of the first representative of the great family of 

 Cavicornia, or hollow-horned ruminants, in the antilopine genus Prolragoc- 

 erus, a small animal with horns laterally flattened, as in the existing goats. 



The giant invader of the period is the narrow-toothed mastodon {Tri- 

 lophodon angustidens) ," named specifically from its long, narrow upper 



' Stehlin, H. G., IJber die Goschichte des Suiden-Gotiisses. Ahh. Schweiz. paUiont. Ges., 

 Vols. XXVI, XXVII, Zurich, 1899-1900, pp. 1-.527. 



^ The type specimen of T. an(justidens is from the Middle Miocene. 



