THE JURASSIC PERIOD 409 



totally disappeared, the mountains which now occupy the 

 same territory having been made at a much more recent 

 date by the reelevation of the same strip. 



LIFE OF THE JURASSIC 



Culmination of the reptiles. In the Jurassic period the 

 reptiles, which had been rising into prominence since the Per- 

 mian, reached the climax of their career. Type after type 

 had made its appearance, until by this time the animals of 

 the reptilian class had assumed most of the roles and taken 



FIG. 433. A Jurassic dinosaur (Stegosaurus) , as it may have appeared in 

 life. (Painted by C. R. Knight, under the direction of Professor H. F. 

 Osborn. Copyright by Amer. Mus. of Nat. Hist.) 



possession of most of the habitats which were open to them. 

 The mammals and the birds were then in a very primitive 

 condition, and occupied an insignificant place. The stations 

 which they have since acquired were then held by the reptiles. 

 The few rather small and unpretentious reptiles which now 

 remain, for example, the snakes, lizards, and turtles, give 

 but a faint conception of the saurian class in its prime. In the 

 Jurassic, there were also large and ponderous reptiles (Fig. 433), 



