THE PERMIAN PERIOD. 



651 



The anomoclonts, in the restricted sense ( = dicynodonts), were 

 highly specialized forms notable for their toothless jaws, or else jaws 

 with single tusk-like teeth. The rest of the jaw was protected by a 

 horny covering such as turtles have. Some features of their skulls 

 also were curiously chelonian in aspect, and there may have been a 

 genetic relation between the anomodonts and the turtles; but the evi- 

 dence at present does not go beyond resemblances. The dicyno- 

 donts were probably herbivorous. The Karoo formation of South 

 Africa has yielded them in greatest abundance, and they have also 

 been found in India, Russia, and Scotland. 



It is not certainly known that the fourth suborder of theromorphs, 

 the Placodontia, were represented in the Permian, though their pres- 



Fig. 303. — View of the right side of the skull of the theriodont Cynognathus cratero- 

 notus, from the Karoo formation, South Africa, showing the striking resemblance 

 of the teeth and skull to a mammalian carnivore. 



ence is probable. They were remarkable for their singularly modified 

 dentition which has no parallel among reptiles. The teeth in front 

 were conical, but the jaws elsewhere, and the palate, bore large molar- 

 like grinding teeth. They are thought to have been allied to the 

 ancestral turtles. These anomalous departures in dentition may 

 have had some relation to the peculiar developments of the vegeta- 

 tion under the stress of the late Permian and early Triassic climatic 

 conditions. 



This rapid and diverse deployment of the early reptiles in a period 

 of general life impoverishment is not a little remarkable, but as it was 



