140 



THE AGE OF MAMMALS 



Middle and Upper Eocene Lifo^ of Europe 



Palceogeographij} — Early in the Lutetian the sea advanced southward 

 around Paris and then proceeded to form the calcaire grassier swperieur, 

 a fluviatile formation which gathered in remains of many ungulates. At 

 the same time there were lake deposits at Argenton (1), a fissure deposit 

 also rich in mammals, and at Lissieu (2) near Lyons. When the upheaval 

 of the Pyrenees began, the climate became warmer. In France we have 



Fig. 48. — Europe in Middle Eocene, or Lutetian times. 



After de Lapparent, 1906. 



White = land. Rided = sea. 



evidence of a flora bearing an African aspect and including oleanders (A'^e- 

 rium). Palms flourished in southern England, and there were water gavials 

 (Gavialis), crocodiles, and giant sea-snakes (Palceophis) . The flora of 

 Bournemouth suggests a comparison of climate with that of the Malay 

 Archipelago and tropical America. 



Our knowledge of the geographical distribution of the mammals rapidly 

 widens, chiefly through the discovery of freshwater and fissure formations 

 all over France and in southern England. 



In the succeeding Bartonian stage there was a fresh marine invasion in 

 the Paris Basin. In the southwest the sea receded as the upheaval of the 

 Pyrenees continued, and in the Paris Basin lagoons began to form. The 

 flora indicates that the climate remained warm as in the Lutetian stage; 

 it includes palms (Sabalites, Flabellaria) , laurels (Laurus), and Podocarpus, 

 a conifer now confined to eastern Asia. 



The Upper Eocene or Ludian stage marks the elevation of northern 



1 Cf. de Lapparent, A., Traite de Geologie, 1906, p. 1513 fol. 



