THE MIOCENE OF EUROPE, ASIA, AND NORTH AMERICA 255 



As regards the liomc of the first hollow-horned ruminants, or Antilo- 

 pina>, there is no evidence in the known Oligoccne of Africa indicating the 

 existence of the ancestors of the true ruminants or selenodont artiodactyls 

 of this tj'pe. The Lower Oligocene artiodactyls of Africa appear to be 

 overflow or outlying forms of the suillines and anthracotheres. Nor do 

 hollow-horned ruminants appear in North America until a late geologic period, 

 the Lower Pliocene ; it is consequently probable that the antelopes, together 

 with the entire stock of Cavicornia, including the Bovina?, or cattle, origi- 

 nated in Asia. 



It is interesting to cast a glance at conditions in the Iberian peninsula, 

 at the mouth of the Tagus.' There was an encroachment of the Atlantic 

 Ocean on Portugal during and before the Early Miocene, due to sinking 

 of the Tagus basin, accompanied by the formation of sea border deposits 

 near Lisbon (Horta de Tripas) containing mammalian remains. Here is 

 found the smallest Sumatran rhinoceros known (Dicerorhinus tagicus), a 

 dwarf ancestor of the D. sansaniensis of the Middle Miocene. Teleoceras, 

 Brnchijodus and Palceochoerus also occur here: the latter (P. aurelianensis) is a 

 small pig, known to have inhabited central France at this time and to have 

 survived into the later Miocene of Switzerland. The felid Pseudcelurus 

 transitorius is a medium-sized form transitional between the larger Oligocene 

 ancestors and its later and still smaller Middle Miocene descendants. 



On the seashores of upper and lower Austria we again discover remains 

 of sirenians (Halitherium christoli)? Another marine deposit is that of 

 the molasse of Briittelen,^ Switzerland, representing a coastal formation 

 occupied by an arm of the sea, in which were deposited the remains of 

 terrestrial and freshwater animals mingled with marine forms. Here also 

 are found tapirs, diceratherine and aceratherine rhinoceroses, suillines, cer- 

 vuline deer, and of especial interest are the remains of an antelope, prob- 

 ably allied to Protragocerus, a small, thickset animal with short, conical 

 bony horns, which inhabited the Rhone valley in the Lower Miocene 

 period. Here again occur remains of the primitive narrow-toothed 

 mastodon (T. angustidens) and of the felid Pseudcelurus. 



Middle Miocene or Vindobonian 



The Middle Miocene, or Vindobonian, is distinguished by a few new 

 arrivals, chiefly from Asia and partly from Africa. These are as follows: 



Ancestral bears, or Ursidie, several branches from Eurasia. 

 Old World or catarrhine monekys (Oreopithecus) , related to the 

 baboons, from Eurasia. 



' Roman and Fliohe, Le Neogdnc Continental dans la Basse Vall6e du Tage, 1907, pp. 44-76. 



' Abel, O., Die .Sircnen der Mediterranen Tcrtiiirbildungen Ostcrreichs. Ahli. K.K. 

 Geol. ReichsansL, Vol. XIX, no. 2, Vienna, 1904 (p. 215). 



^ Studer, T., Die Saugetiorrosto aus den marinon Molasseablagerungen von Briittelen. 

 Ahh. schweiz. paldont. Ges., Vol. XXII, Zurich, 1896, pp. 3-34. 



