OLIGOCENE OF EUROPE, NORTH AFRICA, AND NORTH AMERICA 187 



I. OLIGOCENE LIFE OF EUROPE 



Lower Oligocene, Sannoisian, or Lower Tongrian 



This stage takes its name from the marnes de Sannois in France and from 

 Tongrcs in Belgimn. Accorchng to Deperet ^ the early fauna of the liynites 

 de Celas, Avejan, Vermeil (Fig. 79, 3-5), as well as several deposits in the south 

 of France (6-11), part of Quercy (12), and Frohnstctten in Swabia (17) 

 are of this age. The mammals of these deposits do not i)resent any Oligo- 



FiG. 80. — Entelodonts of the New and Old Worlds. Skeleton of the giant Upper OUgocene 

 entelodont Dinohyus hollandi. In the Carnegie Museum, Pittsburg. After Peterson. 



cene characters; they are simply a continuation of the palseotheres, anop- 

 lotheres, and last of the xiphodonts of the Upper Eocene or Ludian. 



The first real Oligocene fauna is that of the marls of Ronzon (13) in the 

 Rhone valley near Lyons, which succeeds the fauna of the gypse or Ludian, 

 and contains the new Oligocene mammals. Of the same age are the mam- 

 mals of Hempstead (24) (Isle of Wight), of Lobsann (18) (Alsace), Calaf 

 and Tarrega (25, 26) (Spain) numerous deposits in Swabia (19-23), and 

 possibly of Monte Promina in Dalmatia (27). 



The mammals of this stage are of three kinds: (1) those descended from 

 the Upper Eocene fauna of Europe; (2) those of fresh north or south 

 Asiatic origin or previously undiscovered; (3) those apparently from 



' Deperet, L'evolution des Mammif^res tertiaircs; Timportance des migrations (Oligo- 

 cene). C. R. Acad. Sci. Paris, Vol. CXLII, sea. March 12, 1906, pp. 618 seq. 



