THE. TRIASSIC PERIOD. 221 
also are long and pointed, very much compressed, and having 
their lateral margins finely serrated, thus presenting a singular 
Fig. 154.—Triassic Anomodont Reptiles. A, Skull of Dicynodon 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.) 
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 
- 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 Demosauria. 
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 
footprints as well as by their bones; and a question has arisen 
whether the supposed footprints of dzrds which occur in the 
Trias have not really been produced by Deinosaurs. This 
leads us, therefore, to speak at the same time as to the evi- 
dence which we have of the existence of the class of Birds 
during the Triassic period. No actual bones of any bird have’ 
