;06 



ORDERS OF MAMMALIA. 



{" trivertebral bone " of Huxley), which articulates by a 

 movable hinge-joint with the remaining dorsal vertebrae, 

 which are likewise anchylosecl to form a kind of " tunnel 

 or arched bridge of bone." The last two lumbar vertebrae 

 are also fused with the sacral and caudal to form a contin- 



Fig. 61.J. — (Ibjptndon davipes Post Pliocene, Soutli America. 



uous bony mass, whilst the ilia are of enormous size. Un- 

 like the living Armadillos, Glyptodon possesses no movable 

 bands in its armour, the scutes — which are characteristically 

 sculptured in the different species — being in contact by 

 their edges, though not anchylosed. The animal, therefore, 

 possessed no power of rolling itself up for defence against its 

 enemies. 



There are no canine or incisor teeth in Glyptodon, but 

 there are ei^lit molars on each side of each jaw, and the 



crowns of these (fig. 614) 

 are fluted and almost tri- 

 lobed. The teeth form a 

 continuous series, each being- 

 long, arched, and deeply fur- 

 rowed with two parallel 

 grooves on each side ; and 

 all grew from permanent 

 pulps. The feet are massive, and the ungual phalanges are 

 short, compressed, and hoof-like — the fore-feet being tetra- 

 dactylous, and the hind-feet with four or five toes. The 

 length of Glyptodon davijyes (fig. 613), from the tip of the 

 snout to the end of the tail, was more than nine feet. 



The genus Scldsioplewnvm comprises gigantic Armadillos 



Fig. 614. — Fir.st and second molars of CJfip 

 tndiin a^per, viewed from above. (After Bur 

 meister). 



