History of biomineralization in early metazoan clades and the taphonomic phosphatization window at the PC-C boundary

该项目旨在研究Pc-C界线区间早期后生动物的生物矿化演化，并比较冈哇那西部克拉通和地体(扬子和塔里木、哈萨克地体、伊犁地块)邻近克拉通和地体的骨骼和软体化石群落的详细演替。该项目的核心是修订哈萨克斯坦和塔里木等研究较少地区的骨骼化石记录。该项目将为该地区编制一个高分辨率的生物地层对比图，该图还可以确定海相地层的持续时间。西贡德瓦南地区骨骼化石的外观数据将与已公布的全球数据和主要后生动物分支的分子生物学估计的分歧日期进行比较。该项目的关键将是区分真正的生物矿化和成岩矿化。由于生物矿化骨架的表达代表了后生动物早期历史上的重大生物事件，因此将详细研究不同后生动物分支中生物矿化(硅质、磷酸盐、碳酸盐、柠檬质)在PC-C转变过程中的出现。追踪可能的软体奥斯腾型矿床，并与当前项目阶段描述的矿床(胚胎、息肉等)进行比较。将构成拟议研究的一个主要方面。应利用纳米X射线CT和EN-SEM进一步研究硬骨岩、硬骨体，特别是Orsten型化石(软体化石和化石胚胎)的详细构筑。

The proposed project aims at investigating the evolution of biomineralization in early metazoans at the Pc-C boundary interval and to compare the detailed successions of skeletal and softbodied fossil communities at neighbouring cratons and terranes of western Gondwana (Yangtze and Tarim, Kazakh terranes, Yili Block). Central to this project will be the revision of the skeletal fossil record from poorly studied regions, such as Kazakhstan and Tarim. The project will develop a high-resolution biostratigraphic correlation chart for this region, which also allows the determination of durations of hiati. The appearance data of skeletal fossils in the West Gondwanan Region will be compared with published global data and estimates of divergence dates of major metazoan clades by molecular biology. Key to the project will be the discrimination between true biomineralization and diagenetic mineralizations. The appearance of biomineralization (siliceous, phosphatic, carbonatic, limonitic) in various metazoan clades at the PC-C transition will be studied in detail because the expression of biomineralized skeletons represents major biotic events in the early history of metazoans. Tracing of possible soft-bodied Orsten-type deposits and comparison with deposits described in the current project phase (embryos, polyps etc.) will constitute a major aspect of the proposed study. Nano-X-ray CT and en-SEM shall be applied to further study the detailed architecture of sclerites, scleritomes and especially Orsten-type fossils (“soft-bodied” fossils and fossil embryos).