PCA based on 21 external and cranial characters of specimens from Indochinese subregion. A total of 94 specimens were classified into three groups based on 21 external and cranial characters. Specimens from Shan (Muse and Taung Pauk), northern Thailand, northern, central and southern Vietnam clustered as group C (diamond) represents R. a. macrurus; central Vietnam and an individual from east central Myanmar (Keng Tung) formed group B (square) which represents R. cf. affinis, while Cambodian specimens formed the third group A (circle) which represents a subform of R. a. macrurus. Different groups were circled with dashed circles.