234 



HISTORICAL GEOLOGY 



modern forms, such as Turtles, greatly increased, but Lizards were 

 still very subordinate. Crocodiles made their first appearance. 

 As with all the Mesozoic periods, the principal interest surrounds 

 the great groups of remarkable extinct Reptiles such as Enalio- 

 saurs, Dinosaurs, and Pterosaurs. It will be more convenient, 

 however, to describe Mesozoic Reptiles together in a subsequent 

 chapter. 



Birds. — A very important feature from the standpoint of 

 evolution was the introduction of the feathered creatures in the 



Fig. 147 

 The earliest known Bird, Archeopteryx macrura, from the Jurassic. A, 

 right hand; B, right foot; C, restoration modified after Py craft. 

 (From Shimer's "Introduction to the Study of Fossils," courtesy of 

 The Macmillan Company.) 



Jurassic. "The class of Birds is now so distinctly separated from 

 all others and the connecting links obliterated, that the earliest 

 Birds are of especial interest as throwing light on the evolution of 

 this class. Until 1862 Birds had been found only in the Tertiary, 

 and these were already distinctly differentiated as typical Birds. 

 But in that year there was found in the Solenhofen (Bavaria) lime- 

 stone, so celebrated for its marvelous preservations of organisms, 

 a flying feathered biped, and therefore presumably a Bird. But 

 how different from our usual conceptions of this class! Along with 



