Dental: "1) Absence of tooth replacement in the P2, p2, P5, and p5 tooth positions. The retention of the dP5 is responsible for the sharp break in the “premolar”-molar series that has been considered distinctive for Metatheria (e.g., Clemens 1979)." "2) Lateral divergence of lower canines" "3) dp5 cristid obliqua (=ectolophid) very trenchant" Skull: "1) Presence of a posterior masseteric shelf on the dentary" "2) Ventral exposure of the presphenoid" "3) Angular process that is equal to half but less than the length of the dentary ramus" Postcranial: "1) Presence of a capitular tail on the humerus" "2) Testes that descend through the body wall to the scrotum" "3) A small vermis in the cerebellum" "4) Presence of a prehensile tail (convergently develops in many placental mammal groups including rodents, primates, carnivorans)"