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Doushantuo Type Preservation
The preservational mode of the Doushantuo formation involves very early phosphatisation on a cellular level - with cells being replaced by phosphate before they degrade. Occurrence The mode of preservation is typically found in shallow, high energy waters, as lenses of phosphate in carbonate rocks. Its occurrence is assisted by high concentrations of phosphate, which are presumably led to precipitate around the degradation products of cells and cell walls. What is preserved Cells are preserved at a cellular level, with arguments that sub-cellular structures may even represent Cell nucleus, cell nuclei. Bias Although the preservational window is open pretty continually from about through most of the Cambrian, it tends to preserve microscopic things, such as embryos and bacteria. References Doushantuo-type microfossils from latest Ediacaran phosphorites of northern Mongolia [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doushantuo Formation
The Doushantuo Formation (formerly transcribed as Toushantuo or Toushantou, from ) is a geological formation in western Hubei, eastern Guizhou, southern Shaanxi, central Jiangxi, and other localities in China. It is known for the fossil Lagerstätten in Zigui in Hubei, Xiuning in Anhui, and Weng'an in Guizhou, as one of the oldest beds to contain minutely preserved microfossils, phosphatic fossils that are so characteristic they have given their name to " Doushantuo type preservation". The formation, whose deposits date back to the Early and Middle Ediacaran, is of particular interest because it covers the poorly understood interval of time between the end of the Cryogenian geological period and the more familiar fauna of the Late Ediacaran Avalon explosion, as well as due to its microfossils' potential utility as biostratigraphical markers. Taken as a whole, the Doushantuo Formation ranges from about 635 Ma (million years ago) at its base to about 551 Ma at its t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |