412 



HISTORICAL GEOLOGY 



subordinate place on the stage of life in the Jurassic period. 

 The mammals had, indeed, made their appearance as early as 

 the Triassic, but they were still very primitive and quite unlike 

 any forms which exist to-day. Not one, the remains of which 

 have been discovered, was much larger than a rat, and there 

 are reasons for believing that many of them belonged to the 

 lowly group of egg-laying mammals, which is now extinct 

 save for the duckbill and spiny anteater of Australia. 



i 



t ~ -- 



. 



FIG. 436. The earliest known bird (Archaeopteryx). 



Hutchinson.) 



(Modified after 



The earliest of the birds. Our first evidence of the exist- 

 ence of the birds comes from the Jurassic rocks of Germany. 

 In the wonderful lithographic limestone of Bavaria several 

 specimens, including even the feathers, have been found. 

 They represent a bird (Fig. 436) which was so unlike the 

 birds of to-day that, aside from the feathers and the warm 

 blood which those feathers imply, it might with considerable 

 justice be looked upon as a reptile rather than a bird. In its 



