FREE BOOKS

Author's List




PREV.   NEXT  
|<   166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190  
191   192   193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   214   215   >>   >|  
lia, it appears to me to be very probable that it is essentially a remnant of the fauna of the Triassic, or even of an earlier, age[1]; in which case Australia must at that time have been in continuity with the Arctogaeal continent. [Footnote 1: Since this Address was read, Mr. Krefft has sent us news of the discovery in Australia of a fresh-water fish of strangely Palaeozoic aspect, and apparently a Ganoid intermediate between _Dipterus_ and _Lepidosiren_.] But now comes the further inquiry. Where was the highly differentiated Sauropsidan fauna of the Trias in Palaeozoic times? The supposition that the Dinosaurian, Crocodilian, Dicynodontian, and Plesiosaurian types were suddenly created at the end of the Permian epoch may be dismissed, without further consideration, as a monstrous and unwarranted assumption. The supposition that all these types were rapidly differentiated out of _Lacertilia_, in the time represented by the passage from the Palaeozoic to the Mesozoic formation, appears to me to be hardly more credible, to say nothing of the indications of the existence of Dinosaurian forms in the Permian rocks which have already been obtained. For my part, I entertain no sort of doubt that the Reptiles, Birds, and Mammals of the Trias are the direct descendants of Reptiles, Birds, and Mammals which existed in the latter part of the Palaeozoic epoch, but not in any area of the present dry land which has yet been explored by the geologist. This may seem a bold assumption, but it will not appear unwarrantable to those who reflect upon the very small extent of the earth's surface which has hitherto exhibited the remains of the great Mammalian fauna of the Eocene times. In this respect, the Permian land Vertebrate fauna appears to me to be related to the Triassic much as the Eocene is to the Miocene. Terrestrial reptiles have been found in Permian rocks only in three localities; in some spots of France, and recently of England, and over a more extensive area in Germany. Who can suppose that the few fossils yet found in these regions give any sufficient representation of the Permian fauna? It may be said that the Carboniferous formations demonstrate the existence of a vast extent of dry land in the present dry-land area, and that the supposed terrestrial Palaeozoic Vertebrate Fauna ought to have left its remains in the Coal-measures, especially as there is now reason to believe that much of the coal was formed by
PREV.   NEXT  
|<   166   167   168   169   170   171   172   173   174   175   176   177   178   179   180   181   182   183   184   185   186   187   188   189   190  
191   192   193   194   195   196   197   198   199   200   201   202   203   204   205   206   207   208   209   210   211   212   213   214   215   >>   >|  



Top keywords:

Permian

 

Palaeozoic

 
appears
 
Vertebrate
 

Dinosaurian

 
supposition
 

differentiated

 
existence
 

Reptiles

 

present


Mammals
 

assumption

 

remains

 

extent

 

Eocene

 

Australia

 

Triassic

 

unwarrantable

 

reflect

 

surface


hitherto
 

measures

 
reason
 

formed

 

exhibited

 
explored
 

geologist

 

supposed

 

reptiles

 

fossils


suppose

 

Germany

 

localities

 

recently

 

England

 
France
 

regions

 

demonstrate

 

formations

 

Mammalian


extensive

 

Carboniferous

 

respect

 

sufficient

 

Miocene

 
Terrestrial
 
representation
 

related

 
terrestrial
 

formation