ANCIENT BIRDS 
, ifcs curiously “ mixed ” characters. It is certainly one of the most 
i anomalous types of ancient life that has ever been discovered. 
Palaeontologists are now agreed that it was a bird; for it had 
I feathers and claws, as birds have. But what can we say to 
Ij a bird with teeth in its jaws, and with a long, lizard-like tail 
1 such as reptiles have now, except that this tail was provided with 
|j feathers attached in a very peculiar way, contrary to all bird’s 
I tails of the present day ? A naturalist acquainted only with the 
I 
I 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 Archaeopteryx is reptilian, but Mr. W. P. Py craft 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 Opisthocomus. 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 
