126 MAMMALIAN DENTITION 



is a bicuspid tooth. The three molars are subequal in size but 

 the posterior moiety (talonid) of the third is relatively nar- 

 rower and longer than in the others. 



In all the molars the paraconid is lost and the hypoconulid 

 which is present tends to lie toward the inner side. All the cusps 

 are low and rounded and incipient crests connect the proto- 

 conid with the metaconid and with the hypoconid. The last- 

 mentioned is the largest cusp and it is important to note that 

 its base, joining that of the relatively large metaconid, sepa- 



Fig. 44. — Mandibular dentition of Propliopitheeus haeckeli, Schlosser (from cast by 

 Krantz, 9.88-17). An Oligocene omnivorous ancestor of the anthropoids. 



rates the protoconid from the entoconid. The molars are not 

 rhomboidal as in Parapithecus but rather oval with the antero- 

 posterior diameter very little greater than the transverse. The 

 basin-like crown is hollowed for the reception of the protocone 

 of the upper molar. From these features we may infer that 

 the skull had a short stout muzzle, that the area for the tem- 

 poral muscle was small, the upper canine short, the premolars 

 bicuspid and that the molars each presented a typical trigon 

 with the addition of a hypocone. The formula of the man- 

 dible is: 



