In paleontology, Doushantuo preservation is a type of fossilization unique to the Doushantuo formation. It involves very early phosphatisation on a cellular level - with cells being replaced by phosphate before they degrade.[1]
The mode of preservation is typically found in shallow, high energy waters, as lenses of phosphate in carbonate rocks.[1] Its occurrence is assisted by high concentrations of phosphate, which are presumably led to precipitate around the degradation products of cells and cell walls.[1]
Cells are preserved at a cellular level, with arguments that sub-cellular structures may even represent cell nuclei.
Although the preservational window is open pretty continually from about 580 million years ago[verification needed] through most of the Cambrian, it tends to preserve microscopic things, such as embryos and bacteria.[1]