FOSSIL REPTILES. 



193 



degree of knowledge which then existed respecting a department of paliBontology that rapidly 

 acquired an importance and interest unsurpassed by any other branch of fossil osteology. 



The announcement of the founder of palfeontology/ that there was a period when the lakes 

 and rivers of our planet were peopled by reptiles, and cold-blooded oviparous quadrupeds of 

 appalling magnitude were the principal inhabitants of the dry land ; when the seas swarmed with 

 saurians, exclusively adapted for a marine existence, and the regions of the atmosphere were 

 traversed by winged lizards instead of birds ; was an enunciation so novel and startling, as to 

 require all the prestige of the name of Cuvier, to obtain for it any degree of attention and 

 credence, even with those who were sufficiently enlightened to admit, that a universal deluge 

 would not account for the physical mutations which the surface of the earth and its inhabitants 

 had, in the lapse of innumerable ages, undergone. 



Subsequent discoveries have established the truth of this proposition to an extent beyond 

 what even its promulgator could have surmised ; and the " Age of Reptiles " is now admitted into 

 the category of established facts. 



During the incalculable ages which the formation of the various systems of secondary strata 

 must have comprised, we find no evidence in the fossils hitherto observed, of the existence of birds 

 and mammalia, as the characteristic types of the faunas of the dry land. On the contrary, 

 throughout the immense accumulations of the spoils of the ancient islands and continents, amidst 

 innumerable relics of reptiles of various orders and genera, a few jaws and bones of two or three 

 kinds of extremely small marsupials, and the bones of a species of wader, are the sole indications 

 of the presence of the two grand classes of Aves and Mammalia, which now constitute the chief 

 features of the terrestrial zoology of almost all countries. 



The earliest indications of air-breathing vertebrata in the ancient secondary formations are 

 those of small saurian reptiles in the carboniferous strata ; a few vestiges occur in the succeeding 

 group, the Permian. In the next epoch, the Triassic, colossal Batrachians {Labyrinthodonts) appear ; 

 and on some of the strata of this formation are the footmarks of numerous bipeds, presumed to be 

 those of birds ; but at present the evidence of the bones of the animals that made those imprints 

 is required to establish the hypothesis. 



In the succeeding eras, the Lias, Oolite, Wealden, and Cretaceous, swarms of reptiles of 

 numerous genera and species everywhere prevail ; reptiles fitted to fly through the air, to roam 

 over the land, to inhabit the lakes, rivers, and seas ; and yet not one identical with any existing 

 forms ! These beings gradually decline in numbers and species as we approach the close of the 

 secondary periods, and are immediately succeeded in the eocene epoch, by as great a prepon- 

 derance of warm-blooded vertebrata— birds and mammalia — as exists at the present time ; and an 

 equal decadence in the class of reptiles. With the Cretaceous Formation the " Age of Reptiles " 

 may be said to terminate. 



XVII.— Fossil Reptiles of the Wealden. The Iguanodon. The fluviatile deposits (termed 

 Wealden), which in the south-east of England, and in the north of Germany, are intercalated 

 between the oolitic and cretaceous formations, abound in the bones of terrestrial, fresh-water, 

 and marine reptiles, comprising some of the most colossal land-saurians which have hitherto been 

 brought to light. These remains belong to various genera of Chelonians, Saurians, and Croco- 

 dilians; and with these are associated those of flying lizards {Pterodactyles), Plesiosauri, gigantic 

 whale-like reptiles {Getiosmri), and of other oviparous quadrupeds of unknown species and genera. 

 1 In the " Ossemens Fossiles ;" torn. v. Reptiles Fossilea. 



