254 



FIELD ZOOLOGY. 



apex of the first wing bone. In support of the theory of 

 life continuity from simple to complex, it is to be noted 

 that a living South American bird, the hoatzin, while 

 young, has similar hooks at the apex of its first wing bone, 

 and it climbs trees by means of feet, bill, and these claws. 

 Birds have also been discovered in the Cretaceous 

 strata of Kansas. In 1870, Professor Marsh, of Harvard, 

 dug up a specimen of a bird in western Kansas, near the 



Fig. 98. — ArchiBopteryx Uthographica, an early Reptilian Bird. (Galloway, from 



Claus.) 



Smoky Hill river. It was named the Hesperomis, and 

 was evidently a water bird, as it had no wings; but its 

 legs, feet, and tail were remarkably adapted for swimming 

 and diving. Its tail consisted of twelve vertebrae, the 

 hind ones flattened, much as in a beaver's tail. Several 

 other birds have been found in western Kansas and the 

 bones of about fifty different specimens of these birds 

 are in possession of Yale University. 



All the western Cretaceous birds have been found 

 in the soil of western Kansas, except where the same 

 formation in Texas furnished a few; while the eastern 

 Cretaceous birds come from the Green-sand of New 



