HISTORY OF THE EDENTATA 617 



fossil and Recent ; the sacrum had on each side but one point of 

 contact with the hip-bones, and the sternal ribs were not ossified. 

 The shoulder-blade, hip-bones and humerus were all armadillo- 

 like. The plantigrade feet were five-toed and the metapodials 

 were very edentate in form. No indication of bony armour has 

 been found. While these curious animals may very possibly 

 have been referable to the Edentata and, at all events, had 

 several features suggestive of relationship to that order, it can 

 hardly be maintained that they were unequivocal members of it. 

 In the Oligocene of France have been obtained some very 

 fragmentary fossils which were classified and described as 

 armadillos, but their character is quite problematical. It is 

 thus possible, though far from certain, that in the early Ter- 

 tiary, armadillo-like edentates were spread all over the northern 

 hemisphere. 



Suborder fGLVPTODONTiA. fClLYPTODONTS 



In the Pliocene and Pleistocene these huge armoured crea- 

 tures ranged from the southern United States to Patagonia. 

 That they were nearly related to the armadillos is clear, but 

 they were so greatly modified and specialized as to demand 

 recognition as a distinct suborder. 



Aside from their enormous size, the most striking feature 

 of the fGlyptodontia is the extraordinary development of 

 their defensive armour, which was far more complete and mas- 

 sive than in the armadillos. The top of the head was pro- 

 tected by a thick head-shield, or casque, composed of several 

 CO ossified plates ; the body and much of the limbs were en- 

 closed in the immense carapace of elongate-oval, domed shape, 

 which covered the neck and trunk and on the sides almost 

 reached to the ground. This tortoise-like carapace was com- 

 posed of very thick, polygonal plates of bone (no doubt 

 covered externally with horny plates) immovably fixed to- 

 gether by their rough edges, and ornamented with an elaborate 

 pattern of sculpture, which varied according to the genus. 



