:96 



PTERODACTYL AND ARCB1EOPTERYX. 



[Ch. XX 



Fig. 389. 



Skeleton of Pterodactylus 



crassirostris. 



Oolite of Pappenheim, near 



Solenhofen. 



markable example of the variety of fossils winch may be preserved 

 under favorable circumstances, and what delicate impressions of 



the tender parts of certain animals and 

 plants may be retained where the sediment 

 is of extreme fineness. Although the num- 

 ber of testacea in this slate is small, and the 

 plants few, and those all marine, Count 

 Minister had determined no less than 237 

 species of fossils when I saw his collection 

 in 1833; and among them no less than 

 seven species of flying lizards or pterodac- 

 tyls (see fig. 389), six saurians, three tor- 

 toises, sixty species of fish, forty-six of 

 Crustacea, and twenty-six of insects. These 

 insects, among which is a libellula, or dra- 

 gon-fly, must have been blown out to sea, 

 probably from the same land to which the 

 flying lizards, and other contemporaneous 

 reptiles, resorted. 

 In the same slate of Solenhofen a fine example was met with in 

 1862 of the skeleton of a bird almost entire, with the exception of the 

 head, and retaining even its feathers. This valuable specimen is now 

 in the British Museum, and has been called by Professor Owen 

 Archceopteryx macrura. According to his interpretation, it is a true 

 bird, and not intermediate, as was at first imagined, between a bird and 

 reptile. It was about the size of a rook It differs remarkably from 

 all known birds in having two free claws belonging to the wing, and 

 in the structure of its tail ; for in almost all living representatives of 

 the class Aves, the tail feathers are attached to a coccygian bone, con- 

 sisting of several vertebrse united together, whereas in the Archseop- 

 teryx the tail is composed of twenty vertebrse, each of which supports 

 a pair of quill feathers so perfect that the vanes as well as the shaft 

 are preserved. The first five only of the vertebrse as seen in A have 

 transverse processes, the fifteen remaining ones become gradually long- 

 er and more tapering. The feathers diverge outward from them at an 

 angle of 45° ; but this departure from the true ornithic type occurs, 

 says Professor Owen, in that part of the skeleton which is most subject 

 to variation. 



Thus there are short and long-tailed species of bats, rodents, and 

 pterodactyles, with great variation in the number of their caudal verte- 

 brse ; he also observes that although in living birds a short bony tail, 

 and generally accompanied by a coalescence of the terminal vertebrse 

 to form the ploughshare bone/E, is a constant character, yet all birds 

 in their embryonic state exhibit the vertebrse distinct and separate, so 

 that the tail of the Archseopteryx exhibits a retention of structure 

 which is " embryonal and transitory in the modern representatives of 

 the class, and consequently a closer adhesion to the general vertebrate 



