磷酸盐化保存是软躯体化石特异埋藏的一个重要途径, 而微生物在软躯体磷酸盐化过程中可能发挥了重要作用。前人通过埋藏学实验发现, 微生物会在动物胚胎等软躯体组织内部快速滋生, 充填生物体内部空间, 以微生物假形的方式复制了生物体的原始形态。但化石的磷酸盐化过程是否与埋藏学实验模拟的过程一致, 目前仍有争议。本次研究在寒武纪早期宽川铺生物群中发现了一类网格状微体化石。此类化石的保存状态可以根据其中丝状微生物滋生的程度分为三种类型, 它们展示了生物从死亡到微生物侵入、滋生, 最后被磷酸盐化的全过程。这些标本显示, 微生物假形在生物软组织磷酸盐化过程中扮演了重要角色, 但并不是化石磷酸盐化的必由之路, 尤其是当生物体具有矿化硬骨骼或者几丁质软骨骼等抗腐性较强的结构时。此类标本多以不完整保存的残片为主, 正反两面结构一致, 具有典型列状排列的近圆形与哑铃形网孔。由于化石结构简单, 生物学性状较少, 因此它们的亲缘关系尚不明确, 是一类需要继续研究的疑难化石。

Phosphatization is a critical pathway for the exceptional preservation of soft-bodied fossils, with microbes potentially playing a significant role in the process. Previous taphonomic experiments have demonstrated that microbes can rapidly proliferate within soft tissues such as animal embryos, fill the internal spaces of the organism, and replicate its original morphology through microbial pseudomorphisation. However, whether the phosphatization process of fossils is identical to the process simulated by these taphonomic experiments remains contentious. In this study, a new type of reticulate microfossils from the early Cambrian Kuanchuanpu Biota is described. The preservation of these fossils can be categorized into three types based on the extent of proliferation of microbial filaments, indicating the complete taphonomic procedure from the organism's death to microbial invasion and proliferation, and finally to the phosphatization. These specimens indicate that microbial pseudomorphisation plays a significant role in the phosphatization of soft tissues but is not a required pathway, especially when the organisms possess structures with high resistance to decay, such as mineralized skeletons or chitinous cuticles. These new microfossils are mostly preserved as fragments with consistent structures on both sides, featuring characteristic columnar arrangements of nearly circular and dumbbell-shaped perforations Due to the simplicity of the fossil structures and the paucity of biological traits, their phylogenetic positions remain unclear, making them a group of enigmatic fossils that warrant further investigation.

国家自然科学基金委优秀青年基金(42022010)、国家重点研发计划项目(2022YFF0800100)和中国科学院青年创新促进会优秀会员项目(Y2021083)联合资助