ioo MODERN IDEAS OF EVOLUTION 



colossal magnitude, to variety of function and struc 

 ture, to diversity of habitat in sea and on land, alto 

 gether unexampled in their degraded descendants of 

 modern times. Sea-lizards of gigantic size swarmed 

 everywhere in the waters. On land huge quadrupeds 

 like Atlantosaurus and Iguanodon and Megalosaurus 

 greatly exceeded the elephants of later times, and 

 possessed frames and structures now altogether with 

 drawn from the reptiles, and possessed only by 

 mammals and birds. Some of them walked erect on 

 their hind feet, others had true horns like the modern 

 oxen or snout horns like the rhinoceros. Winged 

 reptiles some of them of small size, others with 

 wings twenty feet in expanse flitted in the air. 

 Strangely enough, with these reptilian lords appeared 

 a few small and lowly mammals, forerunners of the 

 coming age. Birds also make their appearance, and 

 at the close of the period forests of broad-leaved trees, 

 altogether different from those of the Palaeozoic age, 

 and resembling the species of our modern woods, 

 appear for the first time over great portions of the 

 northern hemisphere. 



The Kainozoic, or Tertiary, is the age of mammals 

 and of man. In it the great reptilian tyrants of the 

 Mesozoic disappear, and are replaced on land and sea 

 by mammals or beasts of the same orders with those 

 now living, though differing as to genera and species. 

 So greatly indeed did mammalian life abound in this 



1 Ceralopsidcc of Marsh, Am. Jl. Sci, 1889. 



