ANCIENT BIRDS 215 



its curiously " mixed " characters. It is certainly one of the most 

 anomalous types of ancient life that has ever been discovered. 



Palaeontologists are now agreed that it was a bird; for it had 

 feathers and claws, as birds have. But what can we say to 

 a bird with teeth in its jaws, and with a long, lizard-like tail 

 such as reptiles have now, except that this tail was provided with 

 feathers attached in a very peculiar way, contrary to all bird's 

 tails of the present day ? A naturalist acquainted only with the 

 avian life of to-day, would certainly say that it upsets nearly all 

 his ideas of what a bird ought to be ; but that only shows how 

 useless it is (as we have previously pointed out, see pp. 105 and 

 199) to lay down rules for Nature. Its vertebrae are bi-con- 

 cave, like those of fishes and some extinct Saurians. Another 

 very reptilian feature is the presence of " sclerotic plates " in the 

 eye. A pair of feathers sprang from each joint in the tail, which 

 is quite a different arrangement to that in the tail of living birds. 

 The leg-bone and foot are similar to that of modern perching 

 birds, but then we have seen that some of the Dinosaurs, such 

 as the little Compsognathus, had very bird-like feet. The wing 

 shows three free digits or fingers. In form and position these 

 three finger bones are just what may be seen in some young 

 birds of to-day. It has been claimed by some that the fore limb 

 of Archseopteryx is reptilian, but Mr. W. P. Pycraft has shown 

 that it is more bird-like than some people thought, for it much 

 resembles that of a young chick, and still more that of a primitive 

 bird known as Opisthoconms. Another point, established by Marsh, 

 is that the bones of the pelvis are separate not united, as in 

 modern birds. In the London specimen (where the skull is lost) 

 there remains a cast of what is supposed (perhaps wrongly) to be 

 the brain cavity. Were it not for the feathers, perhaps no 

 one would at first have thought of calling it a bird. It combines 



