Multiple-approaching to architectures and micro-structures of the Siliurian chain corals Halysites from the Shiniulan Formation, Guizhou, South China

In Guizhou province, Silurian reefs are mostly composed of Tabulate corals, Stromatoporoids, Rugose. As the main reef-building organism, coral reefs have always attracted the attention of researchers. In previous study, predecessors mainly focus on the morphology and taxonomy of coral fossils, using traditional thin slices and hand specimen analysis methods, but the thin slices cause irreversible damage to the fossil, and this method leads to loss of useful information, hand specimens can only provide surface information, can not observe the three-dimensional information of fossils from multiple angles. Therefore, non-traditional micro-XRF, Micro-CT, SEM and Raman were applied in Halysites researches that 2D compositional analysis and 3D microscopic nondestructive morphology reconstruction were established. Chain corals and fillers in the marl are preserved as Calcium Carbonate, however, the fossils are significantly more enriched in C, and Ca elements, coral polyps Coral worms secrete Calcium Carbonate to create hard housing, and provide protection for soft bodies. Coral individuals are linked by connecting Tabule, and no structure such as connecting pore and connecting plate are observed. Tabulate coral is the primary teaching specimen, providing a model for understanding coral reef building. Combined with the thin section and CT, It allows for a simple and intuitive way of teaching paleontology. Meanwhile, This paper is an endeavor to provide comparable examples of skeletal Ca-Carbonate of post-Cambrian colony animals as to understand the diversity of structural patterns and growth modes in earliest skeletal metazoans across the Ediacaran-Cambrian boundary.