Dengying Formation | |
---|---|
Stratigraphic range: Ediacaran ~ | |
Type | Formation |
Sub-units | See: Members |
Underlies | Yanjiahe Formation [1] |
Overlies | Doushantuo Formation |
Location | |
Region | Yangtze Gorges |
Country | China |
The Dengying Formation is an upper Ediacaran (551-541 Ma [2] ) fossiliferous geologic formation found in South China. It was deposited on a shallow marine carbonate platform. [3]
Listed by ascending age:
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. [3]
The Ediacaran period is a geological period of the Neoproterozoic era that spans 96 million years from the end of the Cryogenian period at 635 Mya, to the beginning of the Cambrian period at 538.8 Mya. It is the last period of the Proterozoic eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian period marks the start of the Phanerozoic eon where recognizable fossil evidence of life becomes common.
The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.
Pteridinium is an erniettomorph found in a number of Precambrian deposits worldwide. It is a member of the Ediacaran biota.
Dickinsonia is a genus of extinct organism, most likely an animal, that lived during the late Ediacaran period in what is now Australia, China, Russia and Ukraine. It is one of the best known members of the Ediacaran biota. The individual Dickinsonia typically resembles a bilaterally symmetrical ribbed oval. Its affinities are presently unknown; its mode of growth has been considered consistent with a stem-group bilaterian affinity, though various other affinities have been proposed. The discovery of cholesterol molecules in fossils of Dickinsonia lends support to the idea that Dickinsonia was an animal, though these results have been questioned.
The Doushantuo Formation 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 at its base to about 551 Ma at its top, with the most fossiliferous layer predating by perhaps five Ma the earliest of the 'classical' Ediacaran faunas from Mistaken Point on the Avalon Peninsula of Newfoundland, and recording conditions up to a good forty to fifty million years before the Cambrian explosion at the beginning of the Phanerozoic.
Hiemalora is a fossil of the Ediacaran biota, reaching around 3 cm in diameter, which superficially resembles a sea anemone. The genus has a sack-like body with faint radiating lines originally interpreted as tentacles, but discovery of a frond-like structure seemingly attached to some Heimalora has added weight to a competing interpretation: that it represents the holdfast of a larger organism.
Rangea is a frond-like Ediacaran fossil with six-fold radial symmetry. It is the type genus of the rangeomorphs.
The Guanling Formation is a Middle Triassic geologic formation in southwestern China.
The Lantian Formation is a 150-meter-thick sequence of rocks deposited in Xiuning County, Anhui Province in southern China during a 90-million-year epoch in the Ediacaran period. Its algal macrofossils are the oldest large and complex fossils known.
Anhuiphyton lineatum is an extinct species of Neoproterozoic algae, known from several fossils from the Lantian formation located in Anhui province,China, first described in 1994. It lived probably more than 580 million years ago. The thalli were of spherical to elliptical shape, made of thousands of flexible septated filaments. The whole organism was a few centimeters in size. Along with Flabellophyton, it is one of the few septated algae found in the assemblage.
The Yanjiahe Formation is an Ediacaran to Cambrian fossiliferous geologic formation found in South China.
Lamonte trevallis is an ichnospecies from the late Ediacaran sediments of the Yangtze Gorges of Southern China. It represented fairly large traces that indicate burrowing behaviour. It had Millimetre-sized traces preserved differently than other Ichnofossils from that time period. Surface-dwelling trackways, vertical burrows and horizontal tunnels are a common characteristic of the trace fossil.
Wutubus annularis is a tubular Ediacaran fossil from China. It is the only species in the genus Wutubus. The genus name was derived from the fossil locality near the village of Wuhe and from Latin tubus (tube), and the species epithet derived from Latin, annularis, with reference to the transverse annulae on the tube.
Orbisiana is an Ediacaran benthic organism formed out of series of agglutinated spherical or hemispherical chambers. It is believed to be a close relative of Palaeopascichnus.
Yilingia spiciformis was a worm-like animal that lived between approximately 551 million and 539 million years ago in the Ediacaran period, around 10 million years before the Cambrian explosion. A fossil of this creature and its tracks were discovered in 2019 in Southern China. It was a segmented bilaterian, conceivably related to panarthropods or annelids. It is a rare example of a complex Ediacaran animal that is similar to animals that existed since the Cambrian, hence suggesting that perhaps the Cambrian explosion was less sudden than often assumed.
Paracharnia is a reassessed genus of a fossil reported by Ding and Chen (1981). It is the first Ediacaran metazoan fossilized remains found in China, taken from the Shibantan Member, Dengying Formation, Sinian System in the Eastern Yangtze Gorge, Hubei Province. It was initially classified as Charnia dengyingensis, but Sun Weiguo in 1986, comparing this to findings from Charnwood in England and the Ediacara assemblage of South Australia, identified it as a new genera. Paracharnia is a pennatulid within the taxon of Rangeomorpha. It is closely associated with macroscopic algal remains of Vendotaenia and dense Cambrian shelly fossil deposits, suggesting its paleontological relevance.
Bilinichnus simplex is a trace fossil from the Ediacaran period which consists of two parallel ridges on sandstone bed sole which have been interpreted as trails of peristaltic locomotion of a unknown gastropod-like animal leaving these traces behind or as pseudofossil of some kind.
Curviacus is a genus of Ediacaran organism of uncertain lineage that displays a modular body plan consisting of crescent shaped chambers. It contains a single species, Curviacus ediacaranus.
Shuhai Xiao is a Chinese-American paleontologist and professor of geobiology at Virginia Tech, Blacksburg, Virginia, U.S.A.