CAINOZOIC AGE 



EOCENE PERIOD 



The passage time from the Cretaceous to the succeeding 

 Eocene is shrouded in darkness : and the " new dawn " 

 follows a long night. It is as if the lights in a playhouse had 

 been abruptly extinguished, and after a lapse had been 

 restored, disclosing a stage crowded with new characters. 



The transition times were doubtless of long duration, and 

 fuU of stirring events ; but their archives for the most part 

 have either been destroyed, or have yet to be discovered. 

 The results, however, of what then took place are plain 

 enough. There had been a great ehmination of old forms of 

 reptile and other Ufe ; and mammals had become dominant. 

 Dinosaurs, herbivorous and carnivorous, had one and aU 

 vanished from the scene — iguanodonts with their spiked 

 thumbs, stegosaurs with their battlemented backs, and the 

 rest of the fraternity. Old Triceratops with his thrice-horned 

 head, and Ehzabethan frill, seems to have held out as long as 

 any; but fortune failed him at last. In short, the old reptile 

 nobility, unable to march with the times, had been swept 

 away. Nor had ichthyosaurs, plesiosaurs, mosasaurs, and 

 flying lizards fared any better. They had all quitted the 

 stage, never to return. 

 MAMMALS Mammal Ufe, now triumphant, was represented by forms 

 far surpassing in variety and importance the primitive 

 creatures known in earlier times. The predominance of 

 mammal over reptile Hfe can hardly have been obtained by 

 brute force ; for there is no reason to suppose that primitive 

 mammals were either warriors or flesh-eaters. Various 

 geographical and climatic changes may have helped to shift 

 the sovereignty; but the superior intelligence and higher 



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