CHAPTER XV 



THE HYRACES 



Features of the Hyrax dentition — Similarity of its cheek teeth 

 to those of Eocene Perissodactyls — Relationships of Hyrax 

 — Resemblances to Perissodactyla and to Proboscidea — A 

 Mammal retaining primitive features is not necessarily out 

 of harmony with its environment. 



These curious little animals (Fig. 81) from Africa and Asia 

 Minor are somewhat of a zoological puzzle. They are of brows- 

 ing habits feeding upon the leaves and young shoots of trees 

 and bushes. The dental formula is: 



i|,C^,Pt,m|. total 36. 

 2 4 3 



The large median upper incisors are triangular in section in 

 the male, oval in the female, elongated and at first sight rodent- 

 like in appearance. Like those of the Rodent they possess also 

 persistently growing roots but the enamel is not confined to the 

 anterior surface. The second upper Incisors are tiny and very 

 early lost. They are represented in the figured specimen 

 merely by remnants of their alveoli. The lower incisors are 

 rather procumbent, have persistently growing roots and present 

 a comb-like appearance from elongation of the three tubercles 

 which cap the crown. They occlude behind the upper incisors. 

 After a short interval come the premolars all of which are 

 molariform and increase in size from before backAvard 

 whereas the molars present a decrease from before backwards. 

 Comparison with Eohippus brings out a striking resemblance 

 between the brachyodont* cheek teeth of Hyrax and those of 



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