The Doushantuo Formation (Chinese: 陡山沱; pinyin: dǒu shān tuó) is a Lagerstätte in Guizhou Province, China that is notable for being 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 is of particular interest because it appears to cover the boundary between the enigmatic organisms of the Ediacaran geological period and the more familiar fauna of the Cambrian explosion of lifeforms whose descendents are recognizable. Taken as a whole, the Doushantuo Formation ranges from about 635 Ma (million years) ago at its base to about 551 Ma at its top, predating by perhaps five Ma the earliest of the 'classical' Ediacaran faunas from Mistaken Point on the Avalon pe