xxn. 4 EDENTATES 593 



Suborder 2. Xenarthra. Palaeocene-Recent. Central and S. 

 America 



Infraorder 1. Cingulata. Palaeocene-Recent 

 Superfamily 1. Dasypodoidea. Armadillos 



Dasypus, nine-banded armadillo 

 *Superfamily 2. Glyptodontoidea. Upper Eocene-Pleistocene 



*Glyptodon 



Infraorder 2. Pilosa. Upper Eocene-Recent. Central and S. 

 America 

 *Superfamily 1. Megalonychoidea. Ground sloths. Upper 

 Eocene-Pleistocene 

 * Megatherium ; *Mylodon 

 Superfamily 2. Myrmecophagoidea. Ant-eaters. Pliocene- 

 Recent 

 Myrmecophaga, giant ant-eater; Tamandua, tamandua; 

 Cyclopes, two-toed ant-eater 

 Superfamily 3. Bradypodoidea. Sloths. Recent 



Bradypus, three-toed sloth; Choloepus, two-toed sloth, 

 unau 



Order 7. Pholidota 



Family Manidae. Oligocene-Recent 



Manis, scaly ant-eater (pangolin), Asia, Africa 



The reduction or loss of the teeth with adoption of a diet of soft 

 invertebrates and especially ants has occurred independently at least 

 five times among mammals ; this habit is indeed to be expected, since 

 the whole mammalian stock was at first insectivorous. We have already 

 noticed the occurrence of ant-eating characteristics in the echidnas and 

 in Myrmecobius, the marsupial ant-eater. Among eutherians the habit 

 is well developed in animals of three different types, (1) the ant-eaters 

 of South America, Myrmecophaga and its allies, (2) the pangolins of 

 Africa and Asia, Manis, and (3) the aardvark or Cape ant-eater 

 (Orycteropus) . These ant-eating animals have many features in com- 

 mon. They all possess a long snout and tongue, very large salivary 

 glands, and reduced teeth; because of these similarities they were for 

 a long time classed together as Edentata. It has gradually become 

 apparent, however, that the three groups of placental ant-eaters 

 have evolved separately. The aardvark was probably an early offshoot 

 from the ferungulate stock (p. 704). The pangolins are placed in the 

 Unguiculata, but they represent a separate line, diverging from the 



