THE TRIASSIC PERIOD. 



227 



guished discoverer as the type of a new order, to which he has 

 given the name of Theriodontia. The teeth of this singular 

 form agree with those of the Carnivorous quadrupeds in con- 

 sisting of three distinct groups namely, front teeth or incisors, 

 eye teeth or canines, and back teeth or molars. The canines 

 also are long and pointed, very much compressed, and having 

 their lateral margins finely serrated, thus presenting a singular 

 resemblance to the teeth of the extinct " Sabre-toothed Tiger " 

 (Machairodus} . The bone of the upper arm (humerus) further 

 shows some remarkable resemblances to the same bone in the 

 Carnivorous Mammals. As has been previously noticed, Pro- 

 fessor Owen is of opinion that some of the Reptilian remains 



Fig. 154. Tr lassie Anoinodont Keptiles. A, Skull of Dieynodon lacerticeps. showing 

 one of the great maxillary tusks ; B, Skull of Oudenodon Bainii, showing the toothless, 

 beak- like jaws. From the Trias of South Africa. (After Owen.) 



of the Permian deposits 'will also be found to belong to this 

 group of the " Theriodonts. " 



Lastly, we find in the Triassic rocks the remains of Reptiles 

 belonging to the great Mesozoic order of the Deinosauria. 

 This order attains its maximum at a later period, and will be 

 spoken of when the Jurassic and Cretaceous deposits come to 

 be considered. The chief interest of the Triassic Reptiles of 

 this group arises from the fact that they are known by their 



