| Clemente Formation | |
|---|---|
| Stratigraphic range: Ediacaran | |
| Type | Formation |
| Underlies | Pitiquito Quartzite [1] |
| Overlies | Caborca Formation [1] |
| Location | |
| Country | Mexico |
The Clemente Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.
Apart from the usual Ediacaran animals,the formation also includes 3 mollusks : Korifogrammia , Zirabagtaria, Clementechiton and the trilobite -like Palankiras. [2]
Rodinia was a Mesoproterozoic and Neoproterozoic supercontinent that assembled 1.26–0.90 billion years ago (Ga) and broke up 750–633 million years ago (Ma). Valentine & Moores 1970 were probably the first to recognise a Precambrian supercontinent, which they named "Pangaea I." It was renamed "Rodinia" by McMenamin & McMenamin 1990, who also were the first to produce a plate reconstruction and propose a temporal framework for the supercontinent.
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. It lived during the late Ediacaran. 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.
Treptichnus is the preserved burrow of an animal. As such, it is regarded as the earliest widespread complex trace fossil. Its earliest appearance, around 542 million years ago (mya), which was contemporaneous with the last of the Ediacaran biota, is used to help define the dividing line, considered geologically at 541 mya, between the Ediacaran and Cambrian periods. It is last seen in the fossil record during the Cenomanian.
Inaria is an Ediacaran fossil. It is found in the Chace Range in Australia, and the White Sea area in Russia.
Swartpuntia is a monospecific genus of erniettomorph from the terminal Ediacaran period, with at least three quilted, leaf-shaped petaloids — probably five or six. The petaloids comprise vertical sheets of tubes filled with sand. Swartpuntia specimens range in length from 12 to 19 cm, and in width from 11.5 to 140 cm. The margin is serrated, with a 1 mm wide groove. A 14 mm wide stem extends down the middle, tapering towards the top, and stopping 25 mm from the tip. The stem has a V-shaped ornamentation on it. The original fossils were found at, and named after, the Swartpunt farm between Aus and Rosh Pinah in Namibia. The generic name comes from Swartpunt, meaning black point in reference to the colour of the rocks. The specific name germsi honours Gerard Germs, who studied the Nama formation of geological beds.
Bomakellia kelleri is a species of poorly understood Ediacaran fossil organism represented by only one specimen discovered in the Ust'-Pinega Formation of the Syuzma River from rocks dated 555 million years old. Bomakellia was originally interpreted as an early Arthropod. A study by B. M. Waggoner even concluded that the organism was a primitive anomalocarid and erroneously identified the ridges of supposed Cephalon as being eyes making Bomakellia the oldest known animal with vision. But this hypothesis has not reached acceptance, nor acknowledgement.
The Ediacaranbiota is a taxonomic period classification that consists of all life forms that were present on Earth during the Ediacaran Period. These were enigmatic tubular and frond-shaped, mostly sessile, organisms. Trace fossils of these organisms have been found worldwide, and represent the earliest known complex multicellular organisms. The term "Ediacara biota" has received criticism from some scientists due to its alleged inconsistency, arbitrary exclusion of certain fossils, and inability to be precisely defined.
Mark A. S. McMenamin is an American paleontologist and professor of geology at Mount Holyoke College. He has contributed to the study of the Cambrian explosion and the Ediacaran biota.
Vendoconularia is a genus of Ediacaran organism consisting of a hexagonal cone, which is thought to have housed a tentaculate organism. Three longitudinal bands are interspersed between the six sides of the cone. The discovery of vendoconulariids in Proterozoic strata of Russia confirmed a 1987 prediction that conulariids constituted part of Ediacaran biota.
The Nama Group is a 125,000 square kilometres (48,000 sq mi) megaregional Vendian to Cambrian group of stratigraphic sequences deposited in the Nama foreland basin in central and southern Namibia. The Nama Basin is a peripheral foreland basin, and the Nama Group was deposited in two early basins, the Zaris and Witputs, to the north, while the South African Vanrhynsdorp Group was deposited in the southern third. The Nama Group is made of fluvial and shallow-water marine sediments, both siliciclastic and carbonate. La Tinta Group in Argentina is considered equivalent to Nama Group.
The Gaskiers Formation is a geologic formation in Newfoundland and Labrador. It preserves fossils dating back to the Ediacaran period.
The Renews Head Formation is a geologic formation in Newfoundland and Labrador. It preserves fossils dating back to the Ediacaran period.
The Trepassey Formation is a geologic formation that crops out in Newfoundland. It preserves fossils dating back to the Ediacaran period.
The Conception Group is a geologic group in Newfoundland and Labrador. It preserves fossils dating back to the Ediacaran period. It mainly contains turbidites, but is interrupted by a glacial diamictite, and tops out with sand and siltstones. It corresponds to the lower portion of the Connecting Point Group.
The Buelna Formation is a geological formation in Mexico. It preserves fossils dating back to the Cambrian period.
The Puerto Blanco Formation is a geologic formation in Mexico. It preserves fossils dating back to the Cambrian period.
The La Ciénega Formation is a geologic formation in Mexico. It preserves fossils dating back to the Carboniferous period.
The Gamuza Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.
The Papalote Formation is a geologic formation in Mexico. It preserves fossils dating back to the Ediacaran period.
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