脊椎动物 5.20 亿年至今的路线采用取整后的寒武纪导航上限，而约 5.18 亿年前的澄江 Myllokunmingia 与 Haikouichthys 材料构成直接化石锚点；两者都不等于脊椎动物冠群年代或全球首现。
claim:taxon:vertebrata:root-rangeLower Cambrian vertebrates from south China
Shu, D.-G.; Luo, H.-L.; Conway Morris, S.; Zhang, X.-L.; Hu, S.-X.; Chen, L.; Han, J.; Zhu, M.; Li, Y.; Chen, L.-Z.
年份1999
来源角色primary-study
DOI / ID10.1038/46965
适用范围
range · taxonomy · 拓扑 · 形态 · geochronology
Primary descriptions and a morphology matrix place Myllokunmingia and Haikouichthys among early vertebrates; the Chengjiang sample is not a crown-node date or a global first-appearance survey.