Craseomys regulus Thomas, 1907 —Korean Red-backed Vole

Craseomys regulus Thomas, 1906 [1907] p.863; Type locality- Mungyeong (Mingyong), Gyeongsangbuk Province, Korea.

Clethrionomys rufocanus regulus: Howell, 1929 p.51; Kuroda, 1938 p.58; Tate, 1947 p.263; Ellerman & Morrison-Scott, 1951 p.666; Won, 1958 p.445; Jones & Johnson, 1965 p.374; Won, 1967 p.195; Won, 1968 p.204.

Clethrionomys regulus: Kishida & Mori, 1931 p.377 .

Eothenomys regulus: Corbet, 1978 p.102; Yoon, 1992 p.74; Han, 1994 p.47; Won & Smith, 1999 p.25; Han, 2004c p.130.

Myodes regulus: Musser & Carleton, 2005 p.1025 .

Range: The distribution for Korean red-backed voles covers most of the Korean Peninsula, except the extreme northeastern region and remote islands (Fig. 122). The northern limit of this species reaches Gaemagowon.

Remarks: The species, endemic to the Korean Peninsula, was formerly classified under Clethrionomys rufocanus (Hinton 1926; Ellerman & Morrison-Scott 1951; Gromov & Polyakov 1992; Kaneko 1990), but when Corbet (1978) promoted the Subspecies C. rufocanus regulus to the species C. regulus, he placed C. regulus in the Genus Eothenomys . Kaneko (1990) in a study of red-backed voles inhabiting Russia, northeastern China, and Korea documented morphological distinctions between C. rufocanus and C. regulus and considered the latter to be an endemic species in Korea. The author proposed that the geographical demarcation line between the two species occurred on the western and southern boundary of Gaemagowon (Kaima Plateau), North Korea. Subsequent mitochondrial and nuclear ribosomal DNA analyzes conclusively demonstrated that C. regulus was phylogenetically closer to C. rufocanus (Suzuki et al. 1999) . Wakana et al. (1996) noted that an absence of rooting of molars in the Korean vole was a characteristic that may have developed within a short period of evolutionary time in the population in Korea. The G-banding pattern of regulus was essentially identical to C. rufocanus . Koh et al. (2011) used cytochrome b to confirm that red-backed voles from Korea were Myodes (Craseomys) regulus . Interspecific distances (4.55%) between C. regulus from Korea and C. rufocanus from northeast of Gaemagowon indicated that C. regulus was an endemic, monotypic species in Korea (Koh et al. 2011).