340 



PALEONTOLOGY 



Fig. 10-4. 

 Dentition, lower jaw, of Hycenodon. 



Debruge and Alais, France. The carnassial teeth (m, i, z, 3), 

 instead of being one in number in each ramus of the jaw, as 

 in modern Felines, were three in number, equally adapted by 

 their trenchant shape, to work like scissor-blades on the teeth 



of the upper jaw, 

 in the act of cut- 

 ting flesh. After 

 the small inci- 

 sors came a pair 

 of large piercing 

 and prehensile 

 canines (c), fol- 

 lowed by four compressed pointed and trenchant premolars 

 (jp, 1, 2, 3, 4) in each side of the jaw ; the whole of this carni- 

 vorous dentition conforming to the diphyodont type : — 



i 3 ^, C bl, V % mt* = u. 



3-3 1-] 1 4-4' 3-3 



Genus, Amphicyon. — With the foregoing predecessor of 

 the digitiprade Carnivora was associated a forerunner of the 



plantigrade fa- 

 mily, viz., a large 

 extinct species 

 having the mo- 

 lars tuberculated, 

 after the pattern 

 of those of the 

 bears ; but re- 

 taining, like II //- 

 amodon, the per- 

 fect type of diphyodont dentition. Fig. 105 shows the teeth 

 of one side of the upper jaw of the Amphicyon gigantcus. The 

 first and second molars (in, 1 and 2) have each two tubercles 

 on the outer side and one on the inner side ; the last tubercular 

 molar (m, 3 ) is of very small size. Fossil remains of Antyhi- 



ilgHP? 



I 



Fig. 105. 

 Dentition, upper jaw, of Amphicyon. 



