Pogonomys macrourus Milne-Edwards 1877

Pogonomys macrourus Milne-Edwards 1877, C. R. Acad. Sci. Paris, 85: 1081.

Type Locality: New Guinea, Prov. of Papua (= Irian Jaya), Vogelkop, Arfak Mtns, Amberbaki.

Vernacular Names: Chestnut Pogonomys.

Synonyms: Pogonomys derimapa Tate and Archbold 1935; Pogonomys huon Tate and Archbold 1935; Pogonomys lepidus Thomas 1897; Pogonomys mollipilosus (Peters and Doria 1881) .

Distribution: New Guinea; throughout lowland and midmontane forests from sea level to 1800 m (Flannery, 1995 a:319); also recorded from Yapen and New Britain (Rümmler, 1938; Flannery, 1995 b); represented in the Trans-fly region (near Daru) only by the holotype of mollipilosus .

Conservation: IUCN – Lower Risk (lc).

Discussion: Phallic morphology described by Lidicker (1968). There is appreciable geographic variation in cranial and dental dimensions and proportions among samples of P. macrourus (Musser and Lunde, ms) and its significance should be assessed in a fresh taxonomic revision of the species. The holotype of mollipilosus is a young adult that Tate (1951:280), who examined it, associated with the holotypes of loriae and dryas, although he had "some doubt of the absolute identity of these with mollipilosus ." However, Dennis and Menzies (1979) and Flannery (in litt.), who also studied the holotype, thought it an example of P. macrourus, the New Guinea species with reddish brown upperparts and smaller body size and shorter tail length than P. loriae (which has dark brownish gray upperparts tinged with buff and white underparts). Tate wrote that the dorsal coat of the holotype is reddish brown and the ventral coat creamy white; the color is typical of P. macrourus, and Tate’s cranial and dental measurements (p. 376) are closer to samples of that species than to P. loriae . In their morphometric study, Dennis and Menzies (1979) thought the holotype fell between the clusters of P. macrourus and P. loriae in their discriminant function analysis, but because the specimen came from lowlands of the Trans-Fly region (near Daru) they provisionally identified it as P. macrourus . They also noted (p. 322) that Oldfield Thomas had written on the tag attached to the holotype, "Is a Uromys and I think is the same as Pogonomys macrourus M. Edw. " Thomas had described loriae and dryas and knew the difference between the large-bodied, brownish gray rat those names represent and the smaller-bodied animal with reddish brown fur we know as P. macrourus . The scatter plot of canonical variate scores presented by Dennis and Menzies (1979:321) can also be interpreted differently. We see the score for the holotype of mollipilosus as forming one end of the macrourus cluster and not intermediate in position. Determining the identity of mollipilosus is not a trivial exercise because that name has been used for the population of Pogonomys endemic to the Cape York Peninsula of NE Australia (see generic discussion).