EUROPE BEFORE ARRIVAL OF MAN 



Marsh far down in the Trias as to warrant the 

 belief that mammals had appeared on the scene 

 toward the close of the Permian age ; and no 

 doubt the same will prove true of reptiles. 

 Some of the footsteps on the Triassic rocks of 

 the Connecticut valley are probably footsteps 

 of great struthious birds ; but the oldest bird 

 actually known belongs to the upper Jurassic 

 strata. Throughout the Secondary period the 

 real lords of the creation were the giant reptiles, 

 stalking over the earth, splashing through the 

 sea, and flying on swift bat-like wing overhead. 

 Of these innumerable "dragons of the prime," 

 the iguanodon, from fifty to seventy feet in 

 length, used to be supposed the largest ; but 

 Professor Marsh has lately discovered the at- 

 lantosaurus of Colorado, nearly one hundred 

 feet in length and thirty feet in height, the 

 largest land animal as yet known. The mam- 

 mals contemporary with these monsters seem 

 to have been mostly small insect-eating marsu- 

 pials ; and the forests through which they roamed 

 consisted mainly of palms, tree-ferns, and pines. 

 In the Cretaceous epoch such deciduous trees as 

 the oak and walnut had appeared on the scene, 

 and the great reptiles had become less numer- 

 ous. But it is not until we enter the Tertiary 

 period, halfway through our tenth aeon of geo- 

 logical time, that the face of the earth, with 

 deciduous trees and flowering herbs, and mam- 

 7 



