452 



THE CARNIVORES 



upper jaw, which formed long sabre-like weapons projecting far below the lower 

 jaw, as shown in our greatly reduced figure of the skull of one of the South 

 American species. The great length of the upper tusks must have completely 

 prevented them from biting in the ordinary manner, as, when the mouth was 

 opened to its widest extent, these teeth would still have reached to the lower 

 jaw. Hence the only mode in which they could have been used would appear 

 to have been as striking or tearing weapons when the mouth was closed. In 

 some species the cutting power of these teeth was increased by their sharp edges 

 being finely notched like a saw. 



These sabre-toothed cats seem to have abounded 

 in the Pleistocene and Pliocene epochs of the earth's 

 history, their remains having been obtained from the 

 caverns and other superficial deposits of England, 

 the Continent, Persia, India, and North and South 

 America. They are also known from strata of much 

 older age, having been found in France in rocks be- 

 longing to the upper part of the Eocene period. 



In the Miocene strata of the United States, and 

 also in the Miocene and Upper Eocene rocks of Europe, 

 there are found more generalized cats, many of which 

 differ from existing forms in having three or four 

 (instead of two) premolar teeth in the lower jaw ; while 

 some of them also have an extra molar tooth behind 

 the lower flesh-tooth. In the presence of these addi- 

 tional teeth, they approach the other families of Car- 

 nivores ; and this approximation is also shown by the 

 structure of some of their teeth. Thus in many of them the upper flesh-tooth, 

 instead of having three distinct lobes in the blade as in existing cats, has but two 

 such lobes, as in a dog. In another form the claws, although still retractile, had 

 not the bony sheaths of the modern cats. The animals to which these early cats 

 seem to make the nearest approach are the civets, thus suggesting that the Cat 

 family may have been derived from primitive Carnivores, more or less closely 

 allied to the modern civets and their allies. 



SIDE VIEW OF THE SKULL OF 

 THE SOUTH AMERICAN SABRE- 

 TOOTHED CAT. 



(Greatly reduced.) 



