中国竹鼠属(啮齿目:鼹形鼠科)分类与系统发育研究OA

Species of the family Spalacidae are exclusively subterranean,possessing a suite of phenotypic traits adapted to life in underground burrows,making them an important group for studying adaptive evolution.The genus Rhizomys represents a basal lineage within this family.While recent years have witnessed significant progress in molecular se-quencing and adaptive evolution research on this genus,morphological comparisons and phylogenetic relationships among its constituent species and subspecies remain poorly understood due to limited availability of newly acquired spec-imens,and diagnostic characters still need to be clearly defined.Based on newly collected specimens and museum col-lections from China,we performed a systematic taxonomic study using morphological and molecular phylogenetic ap-proaches.Our results demonstrate that Rhizomys pruinosus,R.sinensis,and R.sumatrensis can be distinguished by their long dorsal guard hairs with white tips,cheek coloration,and the ratio of tail length to head-body length(mean val-ues:42.3％,27.9％,and 34.5％,respectively).The subspecies R.sinensis vestitus is significantly larger than R.s.da-vidi;it has a greatest skull length exceeding 70 mm,longer pinkish-brown tips on the dorsal fur,and greyish-white cheeks.In contrast,R.s.davidi has a greatest skull length less than 70 mm,greyish-brown dorsal fur with noticeably shorter brown tips.Rhizomys pruinosus senex can be distinguished from R.p.latouchei by its robust teeth and sparser dorsal long guard hairs with a shorter white tip section.Phylogenetic reconstruction based on the cytochrome b gene re-vealed a closer relationship between R.pruinosus and R.sumatrensis,with R.sinensis representing an early-diverging lineage within the genus.Interspecific genetic distances ranged from 9.3％to 15.9％.At the intraspecific level,the ge-netic distance was 2.3％between the subspecies R.s.vestitus and R.s.davidi,and 0.4％between R.p.senex and R.p.latouchei,indicating varying degrees of differentiation among subspecies.This study provides foundational data for the systematics of the genus Rhizomys;However,a definitive taxonomic assessment of R.wardi still awaits more com-prehensive sampling.