80 



GUIDE TO THE FOSSIL MAMMALS AND BIBDS. 



Table-ease tropics, lived with the Creodonta both in Europe and North 

 a - America, while other undoubted little pouched animals, 

 such as Upanorthus, accompanied the Sparassodonta and 

 early opossums in South America. Jaws of these small 

 marsupials, some from the Lower and Upper Eocene of 

 England, and from the Lower Miocene of France, are shown 

 in Table case 14a. A few South American jaws are arranged 

 with them. 



Erom these and other considerations it seems likely that 



Pig. 74. — Lower jaw and teeth of Triconodon mordax, from the Purbeok 

 Beds of Swanage ; nat. size. (Table-case-14A.) 



Pig. 75. — Part of lower jaw and teeth of Spalacotherium tricuspidens, 

 from the Purbeok Beds of Swanage ; outline-fig. nat. size, c and -d 

 being lateral and upper views of a molar tooth. (Table-case 14a.) 



Table-case 

 14a. 



the Australian region has remained isolated from the rest of 

 the world since the end of the Secondary epoch, and that its 

 marsupials are the slightly altered survivors of the mammal- 

 life then characteristic of every continent. 



The only known mammals of the Secondary or Mesozoic 

 epoch are creatures about as large as rats, whose jaws and 

 limb-bones have been found in the Upper Cretaceous and 

 Jurassic rocks of North America, and in the Jurassic 

 (Purbeck Beds and Stonesfield Slate) of England. Most of 

 them seem to have been insectivorous marsupials, and one 



