陕南晚震旦世高家山生物群中骨骼化石的电镜扫描显示，Sinotubulites levis壳壁中具有丰富的磷酸盐化球状和丝状体，可分为3种不同类型的微生物组构：1)由相互缠绕的丝状体所组成的藻席状组构；2)由外表面成莓球状，内部中空的球状体紧密堆叠所形成的组构类型；3)由表面极为光滑的球状体堆叠所形成的组构。它们可能分别代表不同类型的矿化蓝藻，依此推断微生物在S.levis壳壁磷酸盐化过程中起着重要作用。在共生的Sinotubulites baimatuoensis和Cloudina壳壁上，极少或完全不存在这些磷酸盐化组构表明微生物的磷酸盐化作用具有专属性，可能由壳壁微结构所决定，具多层状壁的S.levis可能与具许多有机质纹层的多毛类壳壁关系密切。

SEM observation of the earliest skeletal fossils from the late Sinian Dengying Formation in southern Shaanxi, China indicates that the tube wall of Sinotubulites levis is encrusted by phosphate spherical and filamentous structure, possibly reflecting microbially mediated phosphatization of tube wall. Three preservational microfabrics detected, namely mat-like structure formed by intertwining of rigid filaments, densely packed spheres with a distinctive framboidal external surface and hollow centers and tightly packed spherical bodies with extremely smooth external surface, may refer to different types of mineralized cyanopytes. The rarely occurrence and totally absence of phosphatized microbes on the walls of the co-occurred S. baimatuoensis and Cloudina respectively imply that phosphatization of microbes was taxon-specific, and may due to the discrepancy of wall structures. The multi-walled S. levis with smooth outermost surface may be closely related to polychaete tubes with many organic laminae.

Q913.631

国家重点基础研究发展计划(973计划)，中国科学院知识创新工程项目，国家自然科学基金，国土资源部国际合作与科技司资助项目，教育部高校骨干教师资助计划，G 2000077700，KZCX-2-116，49772081,40272013，2000438，，，，，，