THE TERTIARY PERIOD 



317 



ring in immense numbers in some places as, for example, the 

 Atlantic Coast of the United States (Fig. 197). 



Amphibians. — After the culmination of their development in 

 the Triassic, the Amphibians never again assumed much impor- 

 tance. In the Tertiary they were represented 

 only by such modern types as Salamanders, 

 Frogs, and Toads. A four-foot skeleton of a 

 Salamander discovered at Oeningen, Switz- 

 erland, in 1728, attracted much attention for 

 many years. It was called "Homo Diluvii 

 Testis," because it was considered to be the 

 skeleton of a human being killed during the 

 great deluge of Noah. 



Reptiles. — These, too, were quite mod- 

 ern in character, with Lizards, Snakes (all 

 non-poisonous), Crocodiles, and Turtles all 

 common and varied. 



Birds. — These were much more ad- 

 vanced and numerous than in later Mesozoic 

 time, and many of the modern groups had 

 representatives. A few of the more primi- 

 tive or generalized types, however, still existed in the early Ter- 

 tiary. Thus a toothed Bird has been found in the Eocene of 

 England, though it is to be noted that the teeth were not set in 

 sockets but were only dentations of the edge of the bill (Fig. 



198) . Another special feature was 

 the existence of very large, flight- 

 less Ostrich-like forms which at- 

 tained heights up to fully 10 feet. 

 Mammals. — All during the 

 Mesozoic era Mammals existed, 

 but they were represented only 

 by comparatively few, small, 

 primitive forms which always 

 occupied a very subordinate posi- 

 tion in the animal world. Very early in the Tertiary, however, 

 there began a wonderful development of Mammals. Evolution of 

 many of the higher groups went on rapidly, so that by the close of 

 the period the Mammals had become differentiated into most of the 

 principal modern types. One of the most significant features in 



Fig. 197 

 A Shark's tooth from 

 the Eocene of the 

 Gulf Coastal Plain. 

 Length of tooth, 6 

 inches. (After Gib- 

 bes.) 



Fig. 198 

 Head of an Eocene Bird, Odontop- 

 teryx toliapicus, showing teeth. 

 (After Owen.) 



