92 ANIMALS OF THE PAST 
closely allied, and the creeping snake and the 
bird on which it preys are relatives, although — 
any intimate relationship between them is of — 
the serpent’s making, and is strongly objected 
to by the bird. 
But if we compare the skeleton of a Dino- 
saur with that of an ostrich —a young one is 
preferable — and with those of the earlier birds, 
we shall find that many of the barriers now ex- 
isting between reptiles and birds are broken 
down, and that they have many points in com- 
mon. In fact, save in the matter of clothes, 
wherein birds differ from all other animals, the — 
two great groups are not so very far apart. | 
The Dinosaurs were by no means confined ~ 
to North America, although the western United i 
States seem to have been their headquarters, © ‘ | 
but ranged pretty much over the world, for — 
their remains have been found in every conti- q 
nent, even in far-off New Zealand. ‘ 
In point of time they ranged from the Trias _ 
to the Upper Cretaceous, their golden age, | 
marking the culminating point of reptilian life, — 
being in the Jurassic, when huge forms stalked 
by the sea-shore, browsed amid the swamps, or ~ 
