no EXTINCT MONSTERS 



jaws ended in a kind of beak. There are several species, and 

 some attained very large dimensions. 



In Oudenodon Bainii the skull is six inches long. 



Platypodosaurus l is the name given to a considerable portion 

 of the skeleton of a Dicynodont reptile from the Karoo strata of 

 South Africa; but, unfortunately, the skull is unknown, and it 

 may prove to be identical with Oudenodon. The structure of the 

 pelvis, or region of the hips, is remarkably mammalian. The 

 name indicates that it had broad feet. 



The genus Endothiodon represents a remarkable family of large 

 reptiles from the same strata, distinguished by the presence of 

 teeth on the palate. The skull resembles that of Oudenodon, but 

 the muzzle is longer. 



Two genera, Placodus 2 and Cyamodus, from Triassic strata in 

 Germany, represent another group, the Placodonts, which are 

 very remarkable, but unfortunately at present are only known by 

 their skulls. These, however, are sufficiently peculiar to deserve 

 notice. The teeth represent a curious modification previously un- 

 known in the reptile class, but of which the class of fishes affords 

 numerous examples. In the latter genus the skull is as broad as 

 it is long, and the jaws were very strong. This powerful action of 

 the jaws relates to the form and size of the teeth, which are broad 

 and flat, like paving stones, and evidently adapted to crack and 

 bruise shells of molluscs and Crustacea (see Fig. 29). Although 

 now admitted to be a reptile, this remarkable genus was once con- 

 sidered by Agassiz, Owen, and others to be a fish ; but where fossil 

 remains are so imperfect, mistakes may easily be made at first. 



Tapinocephalus 3 and Titanosuchus 4 are the names given to two 



1 Greek plains, broad ; pous, podos, foot ; and sauros, lizard. 



2 Greek plax, plakos, any flat thing ; odous, tooth. 



3 Greek tapeinos, low ; cephalos, head. 



4 Greek titan, a titan; souchos, a crocodile. 



