Although currently represented only by the seven living species of shrew opossums, this order was formerly much more diverse, with more than 60 extinct species named from the fossil record, particularly from the late Oligocene to early Miocene epochs.

[1][2] The earliest paucituberculatans date to the late Paleocene (Itaboraian South American land mammal age).

[3] The group went through a pronounced decline in the middle Miocene epoch, which resulted in the extinction of all families of this order except for the living shrew opossums (Caenolestidae).

Extinct families of Paucituberculatans include Pichipilidae, Palaeothentidae, and Abderitidae.

[4][5] The Paucituberculata were once considered to be closely related to South American polydolopimorph metatherians, however phylogenetic analyses have found this is not true.