xxii. 6 



SKULLS OF ANT-EATERS 



597 



During the Pleistocene and earlier periods, besides the modern 

 armadillos, there were also giant armadillos. The glyptodonts (Fig. 

 372) were a related type, diverging as early as the Upper Eocene, with 

 a skull and carapace composed of many fused small pieces and some- 

 times the well-known 'battle-axe' tail. They show a remarkable con- 

 vergence with tortoises and some dinosaurs and probably lived in 

 deserts. 



6. Ant-eaters and sloths 



The modern soft-skinned edentates (ant-eaters and sloths) are very 

 specialized and not superficially like the armadillos. The enormous 

 ground sloths (Fig. 373), of which there were several families living 



T L 



Fig. 377. Side views of adult skulls of A, Myrmecophaga; B, Tamandua; C, Cyclopes. 



Tamandua and Cyclopes are approximately i J and 3 times the scale of Myrmecophaga. 



T.L. measurement of total length; M.L. of maxilla length. (From Reeve.) 



between the Oligocene and Pleistocene, were in some respects inter- 

 mediate between the two types. They were quadrupedal animals, but 

 the fore-limbs were shorter than the hind and provided with long 

 claws. Probably the ground sloths were largely bipedal, perhaps crawl- 

 ing slowly about with their fore-limbs among the branches and bearing 

 them down with their weight. The brain was small but the teeth large 

 and hypsodont. Nearly fifty genera of ground sloths have been recog- 

 nized and they were evidently successful in the South American 

 forests. * Megatherium was larger than an elephant and a similar form, 

 *Neomylodon } persisted nearly to the present day. Pieces of its skin have 

 been found, and these, even in the favourable conditions, can hardly 



