THE JURASSIC PERIOD. 



103 



ancestry it retained a long, vertebrated tail, reptile-like claws, and 

 fore limbs, teeth set in sockets, biconcave vertebrae, and separate pel- 

 vic bones. On the other hand, its head and brain were bird-like, 

 its anterior limbs adapted to flying in bird fashion, not in pterosaurian 

 fashion, its posterior limbs modified for bird-like walking, and most 

 distinctive of all, it was clothed with feathers. The perfect develop- 

 ment of the feathers, while yet the body retained so many reptilian 

 features, is most notable. But for their fortunate preservation, it is 

 uncertain whether the creature would have been classed as bird or 



Fig. 376. — A pterodactyl, Pterodactylus spedabilis, from the lighographic stone at 

 Eichstadt, Bavaria, about three-fourths natural size. (After H. v. Meyer.) 



reptile. The known species was somewhat under the size of a crow. 

 Two skeletons and a single isolated feather found in the lithographic 

 quarries of Bavaria, are the only relics yet recovered from the Upper 

 Jurassic beds. 



The non-placental mammals. — The marvelous deployment of aquatic 

 and terrestrial reptiles, of pterosaurs and birds, makes the scanty 

 record of the mammals all the more singular. Only a few jaws of the 

 size of those of mice and rats have been found either in America or in 

 Europe (Fig. 378). These low types are referred, without complete 



