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边界层早期后生动物的生物矿化演化，并比较西冈瓦纳大陆（扬子、塔里木、哈萨克、伊犁地块）相邻的古陆和古陆骨骼和软体化石群落的详细演替。该项目的核心将是对哈萨克斯坦和塔里木等研究不足地区的骨骼化石记录进行修订。该项目将为这一地区绘制高分辨率的生物地层对比图，这也有助于确定海蚀期的持续时间。将西冈瓦纳地区骨骼化石的外观数据与已发表的全球数据和分子生物学方法估计的主要后生动物分支的分歧日期进行比较。该项目的关键是区分真正的生物矿化作用和成岩矿化作用。生物矿化（硅质，磷酸盐，碳酸盐，褐铁矿）在各种后生动物分支在PC-C过渡的外观将被详细研究，因为生物矿化的骨骼的表达代表了后生动物的早期历史中的主要生物事件。追踪可能的软体Orsten型沉积物，并与当前项目阶段描述的沉积物（胚胎、息肉等）进行比较。将是拟议研究的一个主要方面。纳米X射线CT和en-SEM将用于进一步研究骨片、骨片体，特别是奥斯滕型化石（“软体”化石和化石胚胎）的详细结构。

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).