1 32 ANIMAL LIFE PAST AND PRESENT. 



groups might well have been supposed to exhaust the 

 peculiarities displayed by the Giant Land Eeptiles. 

 In the very topmost beds of the Secondary rocks of 

 the United States there occur, however, the remains 

 of another group of these creatures, which appear to 

 indicate a special modification of the original stock from 

 which the Iguanodons took their origin, and present 

 some of the most bizarre and strange creatures yet 

 revealed to our astonished gaze in a country where 

 fossil animals appear to have run riot as regards 

 strangeness. The occurrence of these creatures in 

 the topmost cretaceous rocks, at a period just before 

 the whole group of Giant Eeptiles became extinct for 

 ever, is like the final " flare-up " at the close of a dis- 

 play of fireworks, and suggests that the extreme speci- 

 alisation to which these creatures had finally attained 

 rendered them unsuitable for the wear -and tear of life, 

 and thus conduced to their final extinction. 



The reptiles forming this group or sub-group are 

 collectively known as the Armoured and the Horned 

 Dinosaurs. Their pelvis is a modification of that 

 of the Iguanodon, usually exhibiting the backward 

 direction of the pubis and ischium; but the limb- 

 bones were solid, and either the body was covered 

 with huge bony plates and spines, or long horn-cores, 

 like those of the oxen, were present on the skull. 



The Armoured Dinosaurs were first made known 

 to us by more or less imperfect skeletons discovered 

 in the Lias, Kimeridge Clay, and Wealden formations 

 of England. One of the best known of these reptiles 



