138 



EVOLUTION OF MAMMALIAN MOLAR TEETH 



- E 



- D 



C 



FIG. 95. Inferior teeth of various Creodoiits (A-h) and true Carnivores (F, G), showing tlu- 

 homologies of the cusj'S of the specialized lower carnassial tooth. A. Pulaonictis gigantea, Lower 

 Eocene, France, outer view, showing tuberculo-sectorial molars, with a small low talonid. B. 

 Palcfonictis occidentcUis, Wasatch Formation. Lower Eocene, Wyoming, inner view. C. Ambloe- 

 tonv.s xinosus, Wasatch Formation. Worn teeth, inner view, showing reduced talonid (?) D. 

 The same, outer view. E. Milk teeth of Pttti-io/ilis, family Oxysenida:, sub-order Creodonta, 

 (inner view). Bridger Formation, Middle Eocene, Wyoming. Note the lateral compression of 

 the teeth, the enlargement of the protocoiiid and paraconid, the reduction of the metaconid. 

 F. Dinictis felina, mie of the Machserodont Felida;, sub-order Carnivora Vera (Fissijiedia), White 

 River Formation, Oligocene. Inner view showing blade-like character of the tooth, enlargement 

 and separation of the paraconid, reduction of the metaconid and talonid. G. Fclis concolor 

 (Puma). Inner view. Note vestigial character of the talonid (me 4 ), disappearance of the 

 metaconid. 



i 

 i 



2. Convergence of Upper Carnassials in Creodonta and Fissipedia. 



The independent evolution of the carnassial teeth among Creodonta 

 and Fissipedia affords the most distinctive and interesting example of con- 

 vergent evolution, whereby similar adaptations arc reached from dissimilar 



