Main features of the datasets analysed in this study.

Sphy: number of species sampled in the phylogeny; Scounts: number of species sampled in the phylogeny with known chromosome counts; C-range: observed range of chromosome numbers.物种采样量（Sphy）：系统发育研究中被纳入采样的物种总数；已知染色体计数采样物种数（Scounts）：系统发育中具备已知染色体计数信息的采样物种数量；染色体数目范围（C-range）：观测得到的染色体数目取值区间。