The endemic New Guinea rodent Genus Leptomys (Thomas, 1897) used to compromise three species (). Though, after a recent review of the genus the number has increased to five recognized species (Musser, Helgen and Lunde, 2008); L. elegans (Thomas, 1897), L. postmarital (Rümmler, 1932), L. signatus (Tate & Archbold, 1938), L. arfakensis (Musser, Helgen and Lunde) and L. paulus (Musser, Helgen & Lunde, 2008).
Large Leptomys Leptomys elegans (Thomas, 1897)
Type locality: Astrolabe Range, Central Province, Papua New Guinea (Musser, Helgen & Lunde, 2008).
Size and identification:
Distribution: Endemic to Papua New Guinea. This species is recorded from scattered localities throughout south-eastern PNG, along the southern slopes of the Central Cordillera.
Leptomys arfakensis (Musser, Helgen & Lunde, 2008)
Type locality: Arfak Mts (1000m), Vogelkop Peninsula, Papuan Province, Indonesia (Musser, Helgen & Lunde, 2008).
Taxonomy: It was originally identified as ‘‘Melomys levipes’’ (Paramelomys levipes) by Dollman (1930); while subsequent authors have referred these two specimens to Leptomys ernstmayri (Rummler, 1938; Mahoney, 1968; Musser and Carleton, 1993) or L. elegans (Flannery, 1995; Aplin et al., 1999). In an recent revision of the Genus Leptomys((Musser, Helgen & Lunde, 2008) it was declared a species new to science.
Distribution: Indonesian endemic. This species has only been recorded from the Arfak Mts, Vogelkop, north-western New Guinea (Musser, Helgen & Lunde, 2008). The holotype (adult female; BMNH 184.108.40.206) was collected 19 July 1925 by Fred-Shaw Mayer while the second known specimen ("young adult male"; BMNH 29.527.22) was collected at the same date by FSM.