Rolling bones – Taphonomy of Jurassic dinosaur bones inferred from diagenetic microcracks and mineral infillings

摘要: Abstract Dinosaur bones from the Upper Jurassic Shishugou Formation near Qitai in Junggar Basin, NW China, show black manganese oxide and light quartz infillings bone pore space such as Haversian canals diagenetic cracks. The oxides are identified by X-ray diffraction pyrolusite. Some only partially filled with pyrolusite, which forms miniature geologic spirit levels. orientations of these levels have been measured several generations pyrolusite determined, indicating that were turned around once or times during their fossilization. Characteristic desiccation cracks dinosaur indicate deposition on soil surface early diagenesis under dry climate conditions China. During season evaporation resulting capillary forces drove groundwater dissolved manganese-(II)-ions towards further into system bones. Hence was already contact sediment when still lying not yet totally embedded sediment. Mn(OH)2 precipitated high pH late diagenesis, oxidized to MnO2 transformed Mineral fossil thus can yield valuable insights taphonomic history skeletal remains environmental reworking.