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.
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.
Vendobionts or Vendozoans (Vendobionta) are a proposed very high-level, extinct clade of benthic organisms that made up of the majority of the organisms that were part of the Ediacaran biota. It is a hypothetical group and at the same time, it would be the oldest of the animals that populated the Earth about 580 million years ago, in the Ediacaran period. They became extinct shortly after the so-called Cambrian explosion, with the introduction of fauna formed by more recognizable groups and more related to modern animals. It is very likely that the whole Ediacaran biota is not a monophyletic clade and not every genus placed in its subtaxa is an animal.
Yorgia waggoneri is a discoid Ediacaran organism. It has a low, segmented body consisting of a short wide "head", no appendages, and a long body region, reaching a maximum length of 25 cm (9.8 in). It is classified within the extinct animal phylum Proarticulata.
Cephalonega stepanovi is a fossil organism from Ediacaran deposits of the Arkhangelsk Region, Russia. It was described by Mikhail A. Fedonkin in 1976
Rangea is a frond-like Ediacaran fossil with six-fold radial symmetry. It is the type genus of the rangeomorphs.
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.
Proarticulata is a proposed phylum of extinct, bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits, and dates to approximately 567 to 550 million years ago. The name comes from the Greek προ = "before" and Articulata, i.e. prior to animals with true segmentation such as annelids and arthropods. This phylum was established by Mikhail A. Fedonkin in 1985 for such animals as Dickinsonia, Vendia, Cephalonega, Praecambridium and currently many other Proarticulata are described.
Spongiophyton was a thallose fossil of the early to mid-Devonian, which is notoriously difficult to classify.
Ernietta is an extinct genus of Ediacaran organisms with an infaunal lifestyle. Fossil preservations and modeling indicate this organism was sessile and “sack”-shaped. It survived partly buried in substrate, with an upturned bell-shaped frill exposed above the sediment-water interface. Ernietta have been recovered from present-day Namibia, and are a part of the Ediacaran biota, a late Proterozoic radiation of multicellular organisms. They are among the earliest complex multicellular organisms and are known from the late Ediacaran. Ernietta plateauensis remains the sole species of the genus.
The end-Ediacaran extinction is a mass extinction believed to have occurred near the end of the Ediacaran period, the final period of the Proterozoic eon. Evidence suggesting that such a mass extinction occurred includes a massive reduction in diversity of acritarchs, the sudden disappearance of the Ediacara biota and calcifying organisms, and the time gap before Cambrian organisms "replaced" them. Some lines of evidence suggests that there may have been two distinct pulses of the extinction event, one occurring 550 million years ago and the other 539 million years ago.
Horodyskia is a fossilised organism found in rocks dated from 1,500 million years ago to 900 million years ago. Its shape has been described as a "string of beads" connected by a very fine thread. It is considered one of the oldest known eukaryotes.
Protechiurus edmondsi is a species of fossil animal from the Ediacaran Nama group of Namibia. It was initially interpreted as an echiurid worm. It has been placed as a "vendobiont", on the hypothesis that the Edicarian fauna represent a distinct phylum. It has also been suggested that it may be an ecdysozoan.
Andiva ivantsovi is a Vendian fossil, identified to be a bilaterian triploblastic animal in the Ediacaran phylum Proarticulata, known from the Winter Coast, White Sea, Russia. It was first discovered in 1977, and described as a new species in a new genus by Mikhail Fedonkin in 2002. It lived about 555 million years ago. Fossils of Andiva also occur in South Australia. All known fossils of Andiva are external molds.
Arumberia is an enigmatic fossil from the Ediacaran period originally described from the Arumbera Sandstone, Northern Territory, Australia but also found in the Urals, East Siberia, England and Wales, Northern France, the Avalon Peninsula and India. Several morphologically distinct species are recognized.
Gregory John Retallack is an Australian paleontologist, geologist, and author who specializes in the study of fossil soils (paleopedology). His research has examined the fossil record of soils though major events in Earth history, extending back some 4.6 billion years. Among his publications he has written two standard paleopedology textbooks, said N. Jones in Nature Geoscience "Retallack has literally written the book on ancient soils."
Erytholus is a form genus for problematic fossils of Cambrian age in South Australia. It has been of special interest because of its morphological similarity with the Ediacaran fossil Ventogyrus, and may have been a late surviving vendobiont. It could be a slime mold.
Noffkarkys is a genus of problematic fossil first found in the Ediacaran Grant Bluff Formation of Central Mount Stuart, Northern Territory, Australia, and another prostrate frond-like fossil. The genus was named in honor of Nora Noffke.
Dipleurozoa are extinct proarticulate organisms of the Ediacaran period, which had a flat and more or less ovoid shape. Polychaete worms were treated, however it seems more likely that they were vendobionts. The most representative genus is Dickinsonia, which gives the name to the class.
