MAMMALIA. 



77 



burrowing armadillos of the existing pampa are not the 

 degenerate descendants of the gigantic Pleistocene animals 

 just described. If all their ancestors were known, they 

 would probably prove to have been always small ; and they 

 have survived changes which the larger beasts could not 

 withstand, because they exist in comparatively secure retreats 

 and do not need a great amount of food. 



It is sometimes doubted whether the so-called Edentata 

 of the Old World — the pangolins and aard varks — are 

 really related to the South American animals of this Order. 

 Unfortunately, the known fossils do not help to solve the 

 problem. Some small bones from the Oligocene Phosphorites 

 of France, now in the Paris Museum, seem to belong to 

 ancient pangolins ; while skulls, jaws and teeth of the aard 

 vark or Cape anteater (Orycteropus), which is now confined 

 to Africa, are exhibited from the Lower Pliocene of Samos, 

 Greece, and Persia (Table-case 14b). No animals ancestral 

 to these are recognisable. 



Table-case 

 14b. 



Sub-class II. — Metathekia. 



Oedek X.— MARSUPIALIA. 



Like the sloths and armadillos of South America, the 

 kangaroos and wombats of Australia were preceded in the 

 Pleistocene period by comparatively gigantic relatives. The 

 largest of these rivalled the rhinoceros in bulk, and its thigh- 

 bone was so completely adapted for the support of a massive 

 body, that when it was first discovered it was mistaken by 

 Owen for the thigh-bone of an elephant. The jaws, however, 

 and other parts of the skeleton soon enabled Owen to publish 

 a satisfactory account of the animal, which he named Dipro- 

 todon ("two-front-teeth") in allusion to the rabbit-like or 

 wombat-like arrangement of the anterior cutting teeth 

 (incisors). The original specimens from the river deposits 

 of Queensland, many collected by Dr. George Bennett, are 

 arranged in Wall-case 27 and Table-case 15, with the 

 remains of an allied smaller animal, Nototherium, from the 

 same region. Notwithstanding its great size, the general 

 shape of Diprotodon must have been much like that of the 

 existing wombats of Australia, and it seems to be related 

 both to the phalangers and the kangaroos. The skull 

 (Fig. 72) measures about three feet in length. The grinding 

 teeth are ridged, much like those of a primitive elephant 



"Wall-case 



27. 

 Table-cases 

 14, 14a, 15. 



