A new species of the shrew-mouse, Archboldomys (Rodentia: Muridae: Murinae) from the Philippines

A new species of murid rodent belonging to the 'shrew-mouse' genus Archboldomys is described from Kalinga Province in northern Luzon Island, Philippines. This is the third known species of this endemic Philippine genus. The new species is distinguished from its congeners by consistent differences in adult body size, limb and tail proportions, coloration and texture of the pelage, and cranial and dental dimensions. Members of this genus are small, diurnal rodents that feed mainly on earthworms and other soil invertebrates, and occur in high elevation montane and mossy forests habitats. The new species may be restricted to the northern portion of the Cordillera Central, whereas its congeners occur in widely separated highland areas in other portions of Luzon. The fact that similar distribution patterns are seen for members of other endemic genera suggests that habitat vicariance may have shaped much of the diversification of murid rodents on Luzon.