246 GEOLOGY OF CAPE COLONY 



idea of the fauna. Pareiasaurus, the most characteristic 

 member, is a huge, heavily-built reptile about nine feet 

 long and standing three feet in height. The skull has the 

 temporal region roofed over as in labyrinthodonts, and the 

 bones are sculptured in a somewhat similar manner, but 

 the structure of the palate and many other parts of the 

 anatomy show that it is a true reptile, probably more 

 nearly allied to the Cotylosaurs of the Permian of Texas 

 than to any other group. The uniform teeth indicate 

 that the animal was a herbivore, which probably cropped 

 the vegetation that grew on the banks of the Karroo 

 lakes and marshes. Its movements must have been 

 slow and deliberate like those of a tortoise, and the 

 structure of its limb girdles seems to indicate that it 

 walked with its body well off the ground. It is particu- 

 larly interesting as being the first known animal that 

 gave up crawling and took to walking, and there is 

 reason to believe that it was a similar change of habit 

 in some early reptile that started the line of evolution 

 that gave rise to the mammals. 



With Pareiasaurus was associated a somewhat larger 

 but allied form called Tapinocefihalus. Unfortunately 

 little is known of it. Better known is a gigantic car- 

 nivorous reptile called Titanosuchus, which most probably 

 preyed on the huge unwieldy Pareiasaurians. It pro- 

 bably stood about five feet high and was possibly over 

 twelve feet in length. The skull was provided with 

 large incisors and long powerful canine teeth. A smaller 

 closely allied form is called Ddphinoynatlms. 



[NOTE. Both Tapinocephalus and Gorgonops have been found to be 

 Dinocephalians. G. M., p. 401, 1909.] 



