444 



MESOZOIC ERA— AGE OF REPTILES. 



Fig. 699.— Rhamphorhynchus phyllurus (after Marsh). 



The Pterosaurs were of many kinds, which varied in size from two 

 or three feet to eighteen or twenty feet in alar extent. 



Fig. 700.— Restoration of Rharuphorhynchus phyllurus (after Marsh). One seventh natural size. 



Birds. — 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 limestone, so celebrated for its marvelous 

 preservations of organisms, a flying feathered biped, and therefore pre- 

 sumably a bird. But how different from our usual conceptions of this 

 class ! Along with its distinctive bird characters of feet, limb-bones, 

 beak, and especially of feathered wings, it had the long fail (Fig. 

 701) and toothed jaws (Fig. 704) of a reptile. The structure of the tail 

 is especially significant. In ordinary birds the tail proper is shortened 

 up to a rudiment, and ends in a large bone, from which radiate the 

 feathers of the tail-fan. In this earliest bird, on the contrary, the tail 



