I70 BRITISH MAMMALS 



period here is the most specialised, not only of the Machairo- 

 donts, but in some respects of the whole carnivorous group — 

 Eusmilus. One would almost hope that the problem might be 

 explained by a mistake having arisen in the attribution of the 

 few known remains of Eusmilus to such a remote period as the 

 earliest division of the Tertiary Epoch. The remains of Eusmilus 

 would be more in place if they had been found in the Pliocene or 

 Pleistocene. 



Machairodus^ the sabre-toothed " tiger "par excellence, though a 

 little less specialised in teeth, was probably larger in size and 

 more specialised in the structure of its skeleton than Eusmilus^ 

 and is best regarded as heading up all the family or sub-family of 

 the Machairodonts. This genus seems to have arisen in Europe 

 (France) at the end of the Eocene, but not to have reached its 

 full development till long afterwards, in the middle of the 

 Miocene, when it had already spread out into several other 

 species in France, Germany, Greece, and Persia. In the Pliocene 

 period a form of Machairodus had reached England, and its 

 remains are found in Norfolk. During the Pliocene the Machairo- 

 donts also spread into India, and possibly farther east. During 

 the Pleistocene the genus produced several species in North 

 America, and the largest and grandest species with the hugest 

 development of sabre tooth [Machairodus neogaus) spread through 

 South America to Patagonia. The Pliocene species of Machairo- 

 dont which inhabited Eastern England was Machairodus cukridens, 

 which had a very short muzzle and a tremendous chin spread out 

 below in flanges to act as a protection for the long, broad sabre- 

 tusk when the mouth was closed. In this species the edge of the 

 canine tusk was nearly smooth and almost without serrations. 

 In the Pleistocene period, and co-existent with Palaeolithic man in 

 Britain, appeared Machairodus latidens, a more specialised form. 

 This is apparently identical with Machairodus crinatidens, de- 

 scribed also as from the earliest Pleistocene deposits in East 

 Anglia, but chiefly from the Upper Pliocene of Italy and France. 

 Machairodus latidens has a shorter, broader, and thinner canine 

 tusk, both edges of which are sometimes strongly serrated, so that 



