THE ADVENT OF FLOWERING PLANTS 
many places. In consequence, we have some coal seams 
dating from this period. 
Reptile life reached a high level in the Triassic period. 
The Mastodonsaurus giganteus, a fat enormous crocodile, 
inhabited the swamps, and the sand banks beside the 
rivers saw other great crocodiles with spoon-shaped snouts 
called belodons. The dinosaurs were beginning to ter¬ 
rorize the other animals, though they had not yet reached 
their highest development. The earliest known mammals 
appeared. They looked somewhat like the duckbill of 
Australia, the only living mammal which still lays eggs. 
The changes which went on during the Triassic con¬ 
tinued through the Jurassic period. The vegetation be¬ 
came very rich once more, although it did not differ 
much except in details. Animal life now marked the 
highest point in the development of the reptiles. 
A very famous locality of Jurassic deposits is found 
near Solenhofen in Bavaria. The period got its name, 
however, from the Jura Mountains which form the boun¬ 
dary between Switzerland and France, where the charac¬ 
teristic rocks of the period—the type formation—were first 
found and described. The Rock of Gibraltar is entirely 
composed of beds of Jurassic limestone. 
The beds at Solenhofen early became famous for the 
lithographic stone which was secured from the quarries 
81 
