CHAPTER X 



HOMALODONTOTHERIA 



THE forms making up the Homalodontotheria are char- 

 acterized by a dentition which is clearly a derivative of 

 that of Toxodontia, but is distinguished by the teeth being 

 brachydont, by the canines being the teeth which tend to 

 become tush-like, though not advancing to a marked 

 degree. But the distinctive feature of the suborder is 

 found in the feet, which are clawed, the ungual phalanges 

 being deeply cleft; and further, the animals seem to have 

 walked on the sides of the foot, suggesting the Ancylopoda; 

 but there does not seem to have been a phylogeretic re- 

 lationship, rather it is a case of parallel development. 

 Most of the forms found are of considerable size, and they 

 are relatively scarce in all the formations. 



The representatives of the group in the Deseado all 

 belong to the genus Asmodeus, which seems to be directly 

 ancestral to the Santa Cruz genus Homalodontotherium, 

 which seems to be the last representative of the series, no 

 specimens, referable to the suborder having been found 

 in later beds. 



Asmodeus Ameghino 



Asmodeus Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 643. 

 Asmodeus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 476. 



The formula is S T I f , the upper incisors have pits 

 in the crowns; the canines are moderately enlarged; the 

 upper premolars and molars consist of an external wall, 

 with an anterior and posterior lobe, the lower premolars 

 and molars are typically like those of toxodonts. Two 

 species have been distinguished, a larger, A. osborni, and 

 a smaller, A. scotti. Our collection contains seven speci- 

 mens, all of which should apparently be assigned to A. 

 osborni. 



