The Cambrian is well-exposed and widely developed at Yichang of the Three Gorges area, Hubei Province.A fauna of abundant Small Shelly Fossils was yielded in the limestone of the upper portion of the Shuijingtuo Formation, comprising dominated brachiopods, hyoliths, anabaritiids, sponge spicules, and some archaeocyathid fragments. The skeletons of archaeocyathid were preserved as phosphate, and microborings and microorganisms were also directly phosphatized during early diagenesis.  Morphological study suggests that the microbes could be endolithic cyanobacteria Endoconchia lata.