EVOLUTION OF REPTILES. 5 
Their ancestors were backboneless, but were slowly evolving 
a bony structure. We find, too, in the Silurian period 
already referred to that the creatures we call Silurian fish 
abounded, and that these fish were the link between the true 
mailed or scaled fishes with backbones and their more remote 
ancestors of the Ordovician Epoch. 
Later we find some of the denizens of the ocean beginning to 
take to land and develop- 
ing reptile characteristics, 
and throughout that vast 
period of time, known as 
the Carboniferous Period, 
when what is now coal was 
living vegetation upon the 
surface of the Earth, the 
reptiles were slowly but 
surely evolving from Am- 
phibians to true reptiles 
of a higher order. When 
we come to the Mesozoic 
Period we find fossil re- 
mains in more or less pro- 
fusion of great dragon-like 
reptiles, some of which were 
Fic. 2.—The fossil remains of a real bird known as 
nearly a hundred feet long. the Lizard-tailed bird or Archgopteryx. It was 
4 found in the Solenhofen limestone of Bavaria. 
These fossil remains have This strata of rock dates back to the Jurassic 
Period. This means that this bird lived on the 
been put together, and surface of the world millions of yearsago. This 
2 is a more recent creature than the Flying Rep- 
are now to be seen in tiles, having doubtless evolved from them. 
The Archeopteryx was feathered. The back- 
some of the great mu- bone, however, does not terminate at the root 
: of the tail like the birds of to-day, but extends 
stums i1n Europe and the entire length, the feathers jutting out at the 
America sides, From specimen in Berlin Museum. 
As we ascend to the Mesozoic Period into the Tertiary Period, 
we find these great reptilian creatures showing signs of change 
and becoming more like true mammals in shape. During this 
Epoch we find the first fossil remains of true mammals, viz. the 
Ariinoitherium, Dinoceras, Tetrabelodon, Three-toed Horse, and 
others. Ascending higher into the most recent strata known as 
the Pliocene, we find the fossil remains of such animals as the 
Mastodon, Woolly Rhinoceros, Irish Deer, Giant Sloth, and Mam- 
moth, the immediate descendants of which are now living upon 
