Not only most metazoan phyla made their debut at the earliest Cambrian, but also the fossil record like calcareous metaphyte flora and acritarch change dramatically nearly at the same time.
球外部圈层的演替变化，诸如大陆
、磁极移、古气候、大洋球化学性质的变化以
大气氧含量的变化等在时间上与这一生命
件有耦合关系。
现问题，欢迎向我们指正。
