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 cloudinids, an early metazoan family containing the genera Acuticocloudina, Cloudina and Conotubus, lived in the late Ediacaran period about 550 million years ago. and became extinct at the base of the Cambrian. They formed millimetre-scale conical fossils consisting of calcareous cones nested within one another; the appearance of the organism itself remains unknown. The name Cloudina honors the 20th-century geologist and paleontologist Preston Cloud.
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.
Ausia fenestrata is a curious Ediacaran period fossil represented by only one specimen 5 cm long from the Nama Group, a Vendian to Cambrian group of stratigraphic sequences deposited in the Nama foreland basin in central and southern Namibia. It has similarity to Burykhia from Ediacaran (Vendian) siliciclastic sediments exposed on the Syuzma River of Arkhangelsk Oblast, northwest Russia. This fossil is of the form of an elongate bag-like sandstone cast tapering to a cone on one end. The surface of the fossil is covered with oval depressions ("windows") regularly spaced over the surface in the manner of concentric/parallel rows. The taxonomic identity of Ausia is unresolved.
Charnia is a genus of frond-like lifeforms belonging to the Ediacaran biota with segmented, leaf-like ridges branching alternately to the right and left from a zig-zag medial suture. The genus Charnia was named for Charnwood Forest in Leicestershire, England, where the first fossilised specimen was found. Charnia is significant because it was the first Precambrian fossil to be recognized as such.
Kimberella is an extinct genus of bilaterian known only from rocks of the Ediacaran period. The slug-like organism fed by scratching the microbial surface on which it dwelt in a manner similar to the gastropods, although its affinity with this group is contentious.
In Shi'a Islam the guidance of clergy and keeping such a structure holds great importance. There are several branches of Shi'ism, of which Twelver Shi'ism is by far the largest, and each of the branches has different clergy structures. Individual clerics are referred to as mullā or ākhūnd, but since those terms have developed "a somewhat pejorative connotation" since at least the 1980s, the term rūḥānī has been "promoted" as an alternative, "especially by the clerical class itself".
Ediacaria is a fossil genus dating to the Ediacaran Period of the Neoproterozoic Era. Unlike most Ediacaran biota, which disappeared almost entirely from the fossil record at the end of the Period, Ediacaria fossils have been found dating from the Baikalian age of the Upper Riphean to 501 million years ago, well into the Cambrian Period. Ediacaria consists of concentric rough circles, radial lines between the circles and a central dome, with a diameter from 1 to 70 cm.
Aspidella is an Ediacaran disk-shaped fossil of uncertain affinity. It is known from the single species A. terranovica.
Parvancorina is a genus of shield-shaped bilaterally symmetrical fossil animal that lived in the late Ediacaran seafloor. It has some superficial similarities with the Cambrian trilobite-like arthropods.
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.
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.
Vaveliksia is an extinct genus of Ediacaran Sponge-like organism with a long, tubular-shaped body and a attachment disk similar to that of Petalonamids. The Vaveliksia genus contained two species, Vaveliksia velikanovi as well as Vaveliksia vana. The two species vary in appearance to one another, with V. velikanovi having a more tubular-shaped, sack-like morphology with a crown of wrinkles on top of one of its ends as well as possessing a much more disk-like holdfast with V. vana having an appearance more similar to that of a Poriferan, with V. vana having a much more dome-shaped holdfast and a capsule-like body with no crown of wrinkles unlike V. velikanovi.
The Dansirit Formation is a geological formation in Iran. It is Middle Jurassic in age, dating from the Aalenian to Bajocian.
Persimedusites chahgazensis is a Precambrian discoidal species which are believed to have existed primarily during the late Ediacaran period. It was discovered initially in the Kushk Series in the Bafq and Behabad regions of central Iran, along with similarly aged specimen of Cloudina and Corumbella. The body fossils of these disc-shaped organisms are approximately one centimeter in diameter, and were noted to have symmetrical internal lobes, as well as secondary distal branches.
The arboreomorphs (Arboreomorpha) are ediacaran beings of the frondomorph type that had a disk or bulb-shaped anchor on the ocean floor, a central stem and branching. The "branches" were smooth, tubular structures, often swollen with bifurcation and connected together to form a leaf-like structure.
Kuibisia glabra is a sac-like and polyp-like solitary Ediacaran organism. The fossil of Kuibisia was dated to be around 610–640 million years old and was found in a pteridinium deposit at Aar Farm in Namibia, South Africa.
