DO PHALANGERIFORMS (MARSUPIALIA, DIPROTODONTIA) HAVE A HYPOCONE

The identity of some molar cusps of phalangeriform marsupials has been debated, particularly the distolingual cusp of the upper molars, call ed the metaconule or hypocone by different workers. Here, we examine t he molar teeth of two eutherian and two phalangeriform taxa to reconst ruct the positions of cusps and crests during the masticatory cycle. T he major cusp on the distolingual corner of the upper cheek teeth of T richosurus and Pseudocheirus occludes with lower molars in a manner an alogous to the hypocone of Saimiri (Recent, Eutheria, Primates), and n ot to the metaconule of Didelphodus (Eocene, Eutheria, Insectivora). B oth topographical and functional criteria support the identification o f the distolingual cusp of the upper molar of phalangeriforms as a hyp ocone rather than a metaconule as previously proposed.