Preliminary morphological and molecular systematics analysis of Sicista caudata
Since its discovery in 1907,Sicista caudata is represented by only a few specimens,and morphological and molecular data are scarce.Six specimens of S.caudata were collected in the mixed forest of Hengdaohezi region,Hei-longjiang Province,China(altitude about 740 m,44°48'44"N,129°02'04"E)between April and October 2023.Morpho-logical characteristics of S.caudata were summarized based on the original description and the new specimens.The dor-sal hairs of the body are brownish yellow or brown,without a longitudinal line.The ventral hairs are grayish yellow or grayish white.The dorsal of the front and hind feet are of the same color,covered with white hairs.The color of the dorsal of the tail is similar to the color of the dorsal of the body,while the ventral color of the tail is slightly lighter.The color of the tail is non-bicolor.The head-and-body length ranges from 60 to 71 mm,and the tail length from 100 to 116 mm.The tail is 1.5 times longer than the head-and-body length.The greatest length of the skull ranges 19.6-20.9 mm.The phylogenetic tree shows that S.caudata specimens from Heilongjiang,China and from Sakhalin,Russia form sister lineages with a genetic distance of 0.037 6.