Key to families of Rodentia in Korea

1 Hind leg 4 times length of fore leg................................................................ Sminthidae

- Hind leg <4 times length of fore leg....................................................................... 2

2 Cheek teeth> 3 in upper jaw, 3 in lower jaw................................................................. 3

- Cheek teeth 3 in upper jaw, 3 in lower jaw.................................................................. 4

3 Cheek teeth 5 in upper jaw, 4 in lower jaw; prominent postorbital process, small body size (<500 g) with hairy tail. Sciuridae

- Cheek teeth 4 in upper jaw, 4 in lower jaw; postorbital bar present; upper incisors orange; length of maxillary tooth row> 23 mm; large body size (> 2 kg) with naked tail........................................................ Echimyidae

4 Cricetine dental plan: prismatic cheek teeth without prominent cusps (teeth line even in side view); short tail hairy. Cricetidae

- Murine dental plan: cuspidate cheek teeth with cusps in 3 longitudinal rows; long tail with scale and hairs......... Muridae