关键词: 鼠兔亚属, 分类, 种系发生, 分支图

Abstract: Pikas are well represented in China，especially the subgenus of Ochotona．There are 16 extant species of this subgenus in the world, but only two of those species are not distributed in China．This case provides opportunity for us to study the phylogenetic relationships between the species of the subgenus． A cladngram is presented and phylogenetic relationships among species of the subgenus 0chotona are discussed． For comparing the morphological characters of the 14 species of subgenus Ochotona in china, 22 characters are chosen. Plesiomorphis and apomorphic characters are inferred using the ontogenetic rule as well as in-group comparison to establish polarity of the characters. N

Key words: Pika(Ochotona), C1assification, Phylogeny, Cladogram