Apomys datae (Meyer 1899)

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Muridae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 1189-1531 : 1281

Apomys datae (Meyer 1899)

[Apomys] datae (Meyer 1899) , Abh. Mus . Dresden, ser. 7, 7: 25.

Type Locality: Philippines, N Luzon Isl, Lepanto.

Vernacular Names: Northern Luzon Apomys.

Synonyms: Apomys major Miller 1910 .

Distribution: Greater Luzon Faunal Region. Most records come from highlands in N Luzon where it inhabits primary montane forest in the Sierra Madre and Central Cordillera, 760-2500 m ( Heaney et al., 1998; Musser, 1982 b), but the species has also been taken near sea level on W coast of Ilocos Norte Province ( AMNH 252474, 252475).

Conservation: IUCN – Lower Risk (lc).

Discussion: Member of the Apomys datae Group according to Musser (1982 b), who also documented the inclusion of major ; the Mindoran A. gracilirostris is the only other member of the A. datae group (see account below). Standard karyotype (2n = 44, FN = 54) closely similar to A. musculus and the shrew rats Chrotomys (including Celaenomys ) and Rhynchomys and strikingly different from other species of Apomys sampled (Rickart and Heaney, 2002). The karyotype of A. datae , along with a primitive pattern of cephalic arterial circulation, suggest it is the most primitive species within Apomys . It, along with A. gracilirostris , also form the basal clade within the genus as revealed by phylogenetic analysis of mtDNA cytochrome b sequences ( Steppan et al., 2003).