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.
range · taxonomy · topology · morphology · 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.
The 520–0 Ma Vertebrata route uses a rounded Cambrian navigation ceiling, while Lower Cambrian Chengjiang Myllokunmingia and Haikouichthys material at approximately 518 Ma supplies its direct fossil anchor; neither value dates crown Vertebrata or establishes a global FAD.
claim:taxon:vertebrata:root-range