Microhydromys musseri Flannery 1989

Microhydromys musseri Flannery 1989, Proc. Linn. Soc. N. S. W., 111: 216.

Type Locality: Papua New Guinea, West Sepik Province, Torricelli Mtns, Mt Somoro, 1350 m (see Flannery, 1989, for details).

Vernacular Names: Torricelli Mountains Shrew Mouse.

Distribution: Recorded only from the type locality.

Conservation: IUCN – Lower Risk (lc).

Discussion: Represented only by the holotype. A very distinct species that is part of a highland fauna endemic to the N coastal ranges of Papua New Guinea (see account of Paraleptomys rufilatus). Its cranial and dental morphology is most like M. richardsoni, but "both possess a number of independent specializations not seen in the other" suggesting that they "have been evolving separately for a considerable period of time" (Flannery, 1989:220). Flannery preferred to include musseri in Microhydromys rather than its own monotypic genus because doing so would highlight its apparent close morphological affinity with richardsoni, at least "until relationships within the group are clarified" (p. 220), but a new genus will likely have to be erected for the species.