96 



GENERAL ORNITHOLOGY 



PART H 



modifications intermediate in structure between existing R&ptilia, 

 and Aves," and are therefore inferentially in the direct ancestral 

 line of modem Birds. 



Geologic Sueeession of Birds. — Birds have been traced back in 

 geologic time to Cretaceous and Jurassic epochs of the Mesozoic or 

 Mid-Life period of the world's history. The earliest ornithichnites,— 

 the fossils so called because supposed to indicate the presence of 



Birds by their 

 footprints, were 

 discovered ahont 

 the year 1835 in 

 the Triassic for- 

 mation in Con- 

 necticut. But the 

 creatures which 

 made these tracks 

 are now reason- 

 ably believed to 

 have been all 

 Dinosaurian rep- 

 tiles. The oldest 

 ornitkoUte, or- fos- 

 sil certainly 

 known to be that 

 of a true Bird, is 

 the famous Archce- 

 opteryx, found by 

 Andreas Wagner 

 in 1861 in the 

 Oolitic slate of 

 Solenhofen in 

 Bavaria. This has 

 a long lizard-like 

 tail of twenty ver- 

 tebrae, from each 

 of which springs 

 feathers of the wings 

 hand are not fused to- 

 the jaws bear true 



Fio. 14.— Oldest known ornithological treatise, illustrating also 

 the art ot lithography in the Jurassic period, engraved by Arcliceo- 

 ptwyx lithographim. From the original slab in the British Museum ; 

 after A. Newton, Ency. Brit. 



a well-developed feather on each side ; 

 are also well preserved ; bones of the 

 gether, as they are in recent Birds; and 

 teeth. This Bird has served as the basis of one of the primary divi- 

 sions of the class Aves ; though it has many reptilian characters, it 

 is a true Bird. The great gap between this ancient Avian and 

 latter-day birds has been to some extent bridged by the discovery 

 and restoration of Birds from the Cretaceous formations of North 

 America, such genera as Ichthyornis and Hesperornis forming types of 



