 The molars are bunodont ( with the cusps higher than the connecting crests ) and brachydont ( low @-@ crowned ) . On the upper first and second molar , the outer and inner valleys between the cusps and crests do not interpenetrate . Many accessory crests are present , including the mesolophs and mesolophids . The anterocone and anteroconid , the front cusps on the upper and lower first molar , are not divided into smaller outer and inner cusps . Small accessory roots are absent from the molars , so that each of the three upper molars has two roots on the outer side and one on the inner side and each of the lower molars has one root at the front and one at the back . 
