前寒武纪生态系以微生物的繁盛为特征，以叠层石和微生物成因沉积构造的大量发育为标志．后生动物及其遗迹化石出现在新元古代“雪球事件”之后，并与微生物席组成“埃迪卡拉花园”．新元古代的海底以发育完好的微生物席底和微弱的垂向生物扰动为特征，沉积物含水量低、沉积物．水界面平滑稳定；到寒武纪，由于垂向生物扰动的大量增加，微生物席底逐渐衰弱，“显生宙式”的海底沉积物含水量高、上下层沉积物易于混合和悬浮、沉积物一水界面模糊．自寒武纪开始，随着后生动物活动在浅海环境中不断地增多，遗迹化石习性类型趋于多样化和复杂化，微生物席底开始向较深的陆架乃至深海迁移并逐渐消亡．%Precambrian ecosystems are characterized by the flourish of microbiota and wide occurrence of stro- matolites and microbially induced sedimentary structures. Metazoans and their trace fossils, occurong after the Neoproterozoic ＂Snowball Earth＂ event, made up of ＂The Garden of Ediacara＂ with microbial mats. Late Neoproterozoic seafloor were characterized by well-developed microbial mats and poor development of vertical- ly-oriented bioturbation, thus it provied a fairly stable, relatively low water content sediment surface With a sharp water-sediment interface. Microbially-bound seafloor became increasingly scarce in shallow-marine set- tings of Cambrian, largely due to evolution of burrowing organisms with an increasing vertically-oriented com- ponent to their bioturbation. This ＂ Phanerozoic-style＂ seafloor had a blurry water-sediment interface, greater water content, and lacked well-developed microbial mats. With the reworking increase of metazoans in Cam- brian shallow marine settings, the trace fossils tended to be more diverse and complex, and microbial mat- grounds retreated to deep sea and gradually disappeared.
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