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Dengying Formation

The Dengying Formation is an upper Ediacaran (551-541 Ma) fossiliferous geologic formation found in South China. It was deposited on a shallow marine carbonate platform. It also contains a rare example of Burgess Shale-type Preservation within the Ediacaran, in the form of the Tongshan Lagerstätte.

Members

Listed by ascending age:

  • The Hamajing Member is characterized by light grey, medium- to thick-bedded dolomite, intercalated with thin layers of chert.
  • The Shibantan Member is interpreted to represent a subtidal environment and is composed of dark grey, thin-bedded bituminous limestone. It is the most fossiliferous of the Dengying Formation members and has yielded several trace fossils, such as Lamonte, as well as possible lobopodian trackways.
  • The Baimatuo Member consists of light grey, thick-bedded dolomite.

Traditionally, the Tianzhushan Member was considered to be the uppermost unit of the Dengying Formation. However, its small shelly fossils and Micrhystridium-like acritarchs are a shared characteristic with the Cambrian Yanjiahe Formation. The Kuanchuanpu Formation also is occasionally placed as a member of the Dengying Formation, however it is likely separate for the same reasons.

Paleobiota

The Dengying formation is unique from other Ediacaran formations in that its top is almost right up against the Ediacaran - Cambrian boundary, with more recent organisms being described that have striking similarities with Cambrian fauna, like Alienum. There are also a lot of ichnogenera in the form of burrows, something that is common in younger Ediacaran rocks the closer to the Cambrian boundary they are.

A recent paper has also found a rare example of Burgess Shale-type Preservation outside of the known range of all members, in what is known as the Tongshan Lagerstätte. This preserves a wide range of fossil forms, including the first rangeomorph fronds with Burgess Shale-type preservation.

Proarticulata

Petalonamae

Trilobozoa

Porifera

incertae sedis

Flora

Microorganisms

Ichnogenera

Undescribed

See also

References