Rattus marmosurus Thomas 1921

Rattus marmosurus Thomas 1921, Ann. Mag. Nat. Hist., ser. 9, 7: 246.

Type Locality: Indonesia, NE Sulawesi, Minahassa, Gunung Masarang, 2000 ft (610 m).

Vernacular Names: Marmoset Xanthurus Rat.

Synonyms: Rattus facetus Miller and Hollister 1921; Rattus tondanus Sody 1932 .

Distribution: Northern arm and central core of Sulawesi. Absent from SE peninsula where it is replaced by R. salocco and SW peninsula where R. bontanus occurs. Altitudinal range, lowlands to mountain summits in a variety of forest formations.

Conservation: IUCN – Lower Risk (lc).

Discussion: Rattus xanthurus species group. Although marmosurus has been listed as a subspecies of R. xanthurus (Ellerman, 1941; Laurie and Hill, 1954), most researchers besides Thomas have recognized its specific uniqueness (Misonne, 1969; Musser, 1971 e, 1984; Musser and Holden, 1991; Sody, 1941; Tate, 1936). Furthermore, the two are sympatric in NE Sulawesi (Musser, 1971 e). Sody (1941) questionably included marmosurus in Taeromys, but it is a member of the Rattus xanthurus group. Musser (1971 e) explained why tondanus, from the NE arm, is a synonym; facetus is based on a juvenile from the central core of the island. Musser and Carleton (1993) confined the species to NE region of the northern peninsula of Sulawesi, but recent morphometric analyses unequivocally indicate that it is R. xanthurus that is restricted to the NE arm and R. marmosurus that has the wider distribution on the island (Musser, ms).