Archboldomys luzonensis Musser 1982

Archboldomys luzonensis Musser 1982, Bull. Am. Mus . Nat. Hist., 174: 30.

Type Locality: Philippines, SE Luzon Isl, Camarines Sur Province, Mt Isarog, 6560 ft (2000 m).

Vernacular Names: Isarog Shrew Mouse.

Distribution: Greater Luzon Faunal Region where it is endemic to montane habitat on Mt Isarog in SE peninsula of Luzon (Heaney et al., 1999; Rickart et al., 1991).

Conservation: IUCN – Endangered.

Discussion: Morphological descriptions and comparisons with Crunomys and Sulawesi shrew rats provided by Musser (1982 c). Altitudinal distribution and ecologial notes in Rickart et al. (1991), Balete and Heaney (1997), and Heaney et al. (1999). Standard karyotype and G-banding patterns are distinctive (2n = 26, FN = 43): its low 2n, high number of bi-armed chromosomes relative to telocentric elements, and peculiar pattern of the sex chromosomes define a highly derived karyotype compared to those characteristic of other Old Endemics sampled, but is uninformative in assessing the phylogenetic relationships of A. luzonensis among Philippine murines (Rickart and Musser, 1993; Rickart and Heaney, 2002). Morphology suggests a tie to Philippine Crunomys (Musser and Heaney, 1992), but molecular data indicated close phylogenetic alliance with species of Apomys, Chrotomys (including Celaenomys), and Rhynchomys and no close association with species of Crunomys (Jansa and Heaney, 2001) .