With the exception of the aberrant long-snouted phalanger, the members of the family Phalangeridae have the normal number of functional incisors, in addition to which there may be one or two rudimentary pairs in the lower jaw.
The family is connected with the Phalangeridae by means of the musk-kangaroo (Hypsiprymnodon moschatus); forming the sub-family Hypsiprymnodontinae.
In all these features the musk-kangaroo connects the Macropodidae with the Phalangeridae.
By means of the little musk-kangaroo, the cuscuses and phalangers, constituting the family Phalangeridae, are so closely connected with the kangaroos, or Macropodidae, that in the opinion of some naturalists they ought all to be included in a single family, with three sub-families.