DISTRIBUTION OF MAMMALIA IN TIME. 6ll 



pwt of the globe ; and they show that Australia, at no distant 

 geological period, possessed a Marsupial fauna, much re- 

 sembling that which it has at present, but comparatively of a 

 much more gigantic size. In the remains from the Australian 

 bone-caves almost all the most characteristic living Marsupials 

 of Australia and Van Diemen's Land are represented ; but the 

 extinct forms are usually of much greater size. We have 

 Wombats, Phalangers, Flying Phalangers, and Kangaroos, with 

 carnivorous Marsupials resembling the recent Thylacinus and 

 Dasyurus. The two most remarkable of these extinct forms 

 are Diprotodan and Thylacoleo. In most essential respects 

 Diprotodon resembled the Kangaroos, the dentition, especially, 

 showing many points of affinity. 'I"he hind-limbs, however, of 

 Diprotodon were. by no means 

 so disproportionately long as in 

 the Kangaroos. In size Dipro- 

 todon must have many times 

 exceeded the largest of the liv- 

 ing Kangaroos, since the skull 

 measures three feet in length 

 (fig. 238). Thylacoleo was a car- 

 nivorous and predacious Mar- 

 supial, equally gigantic when Fig. 23S.-Skuiiof/).>«r<>w„«^,«^m&. 

 compared with living forms. 



Thylacoleo, in fact, must have been, on a moderate estimate, 

 at least as large as a Lion ; the largest living carnivorous 

 Marsupial being no larger than a shepherd's dog. The flesh- 

 tooth or carnassial molar of Thylacoleo measures two inches 

 and a quarter across, or very nearly d^ble the measurement 

 of the same tooth in the largest existing Lion. 



Order ITT. Edentata. — The Edentates, like the Marsupials, 

 are singularly circumscribed at the present day. No member 

 of the order is at the present day indigenous in Europe. 

 Tropical Asia and Africa have the Scaly Ant-eaters or Pangolins: 

 and in Africa occurs the Edentate genus Orycteroptis. South 

 America, however, is the metropolis of the Edentata, the order 

 being there represented by the Sloths, the Armadillos, and the 

 true Ant-eaters. It is also in South America that by far the 

 greater number of extinct Edentates have been found ; and, as 

 in the case of the Australian Marsupials, the fossil forms are 

 gigantic in size compared with their living representatives. 



The Sloths {Bradypodidce) of the present day were repre- 

 sented i.i Post-tertiary times by a group of gigantic forms 

 referable to the genera Mylodon, Megalonyx, and McgatJierium. 

 Of these, Mylodon attained a length of eleven feet, and Mega- 



