Rattus morotaiensis Kellogg 1945

Rattus morotaiensis Kellogg 1945, Proc. Biol. Soc. Wash., 58: 66.

Type Locality: Indonesia, Moluccas, Pulau Morotai, off N coast of Pulau Halmahera.

Vernacular Names: Halmahara Rat.

Distribution: Endemic to the Halmahara Isls; recorded from Morotai, Halmahara, and Batjan Isls (Flannery, 1995 b).

Conservation: IUCN – Lower Risk (lc).

Discussion: Rattus species-group unresolved. Arboreal, and the only recorded murine endemic to the Halmahara Isls. Kellogg (1945) regarded R. morotaiensis to be more closely related to the New Guinea species (" R. ringens group") than to Sundaic species (" Rattus rajah group"), but morphology of the Halmahara rat indicates otherwise (K. Aplin, in litt., 2004). It is characterized by a suite of distinctive external traits (very spiny fur, long slightly tufted tail), cranial conformation, and molar structure (posterior cingula on upper molars, large peg-like anterolabial and anterolingual cusps on m1, wide cingular margins on m2, and crenulated enamel on all molars) not found in any other species of Rattus from New Guinea, the Moluccas, or anywhere else (Musser and Holden, ms). Reviewed by Flannery (1995 b).