FIG. 172. A. Upper and lower molar of a Lower Eocene (Wasatch) Tapiroid Systemodon 



.*' mt/tiaiix (.^) 



B. Upper molar of a recent Tapir Tiijiiri'* innericanv.s, showing the completed bilophodont 

 pattern, x ^-. 



is 



FIG. 173. Bunolophodont teeth of a primitive Tapiroid (Systcmodon priinn rug), from the 

 Wasatch Formation, Lower Eocene. Observe the general similarity in pattern to the teeth of 

 contemporary Equidfe (Fig. 166) combined with a stronger development of the protoloph 

 and metaloph, a greater obliquity of the tooth as a whole, and a somewhat more central position 

 and larger size of the paracone. x i . After Wnrtman. 



FIG. 174. Evolution of the premolars in Protapims and Tnpirus. After Wortman and Earle. 



A. Protapirus simplex. Oreodon Beds, Middle Oligfocene. 



B. Protapirus obliquidena. Protoceras Beds, Upper Oligocene. 



C. Tupii'us a/inericanus. 



In A, premolars 1-4 are all comparatively simple and there is no metaloph. 



In B, the internal cusp (deuterocone) of p 3 , JD-I has split into two and there is an imperfect 

 metaloph. 



InfC, p2-p* are fully molariform. x^. After Wortman and Earle. 



