The Vendian biota (also known as Ediacaran Biota, Vendian forms, Vendian fauna(s), Vendobionta or Vendozoa) are a group of ancient lifeforms that are found in rocks of the Ediacaran Period, a bit older than the Cambrian faunas that represent the oldest (shelly) fossils of classical paleontology. Sedimentary, volcanic, plutonic, metamorphic rock types of North America. ... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ... A paleontologist carefully chips rock from a column of dinosaur vertebrae. ...

The original descriptions came from the Ediacaran faunas of South Australia. It later turned out that similar faunas found in Namibia had been previously described, but their great age had not been appreciated. Subsequent discoveries have found similar fossils in Brazil, Antarctica, Newfoundland, the Canadian Maritimes, North Carolina, England, Canada's Northwest Territories, the western United States, Scandinavia, the White Sea, Siberia and Ural region of Russia, Poland, and other places. The Ediacaran period is the last geological period of the Neoproterozoic Era, just before the Cambrian. ... Motto: United for the Common Wealth Nickname: Festival State Other Australian states and territories Capital Adelaide Government Governor Premier Const. ... Newfoundland (French: Terre-Neuve; Irish: Talamh an Éisc; Latin: Terra Nova) is a large island off the north-east coast of North America, and the most populous part of the Canadian province of Newfoundland and Labrador. ... The Maritimes or Maritime provinces are a region of Canada on the Atlantic coast, consisting of New Brunswick, Nova Scotia and Prince Edward Island. ... State nickname: Tar Heel State Other U.S. States Capital Raleigh Largest city Charlotte Governor Michael Easley Official languages English Area 139,509 km² (28th)  - Land 126,256 km²  - Water 13,227 km² (9. ... Royal motto: Dieu et mon droit (French: God and my right) Englands location within the UK Official language English de facto Capital London de facto Largest city London Area  - Total Ranked 1st UK 130,395 km² Population  - Total (2001)  - Density Ranked 1st UK 49,138,831 377/km² Ethnicity... A former territory in the United States is called Northwest Territory. ... Scandinavia, Fennoscandia, and the Kola Peninsula. ... Barents Sea, the Kola Peninsula and the White Sea. ... Siberia Siberia (Russian: Сиби́рь, common English transliterations: Sibir, Sibir; possibly from the Mongolian for the calm land) is a vast region of Russia and northern Kazakhstan constituting almost all of northern Asia. ... See: Ural Mountains Ural River IMZ-Ural Russian motorcycle Ural automobile This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

These now extinct forms are generally segmented or frondlike with no visible organs other than holdfasts in some varieties. Many of these fossils are difficult to interpret. They are probably entirely late Precambrian, although some possible Vendian forms have been identified in the Cambrian. Many believe that some or all of the Vendians are precursors to one or more modern phyla that arose in the Cambrian. A holdfast is a rootlike plant structure that anchors a seaweed. ... The Precambrian or Cryptozoic is the period of the geologic timescale from the formation of Earth around 4500 million years before the present (BP) to the evolution of abundant macroscopic hard-shelled fossils, which marked the beginning of the Cambrian, some 542 million years BP. Remarkably little is known about... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ... Scientific classification or biological classification refers to how biologists group and categorize extinct and living species of organisms. ...

The Vendian "animals" (assuming that they were animals) are probably too large and complex to be single-celled. They universally lack preserved mouths, any organs, or appendages. Symmetries may be two-, three-, four-, or even five-fold. Movement traces are known for some organisms, such as Dickinsonia, Kimberella, and Yorgia. Some appear to be or have holdfasts. They include frond-like forms (e.g. the rangeomorphs), disks with various ornamentations, what appear to be air mattress-like forms, and other unlikely shapes. They were originally thought to be simple precursors of more modern forms, and a few elements of the fauna still look like possible precursors of such later forms as arthropods and molluscs. But most appear to belong to some evolutionary sidetrack. It has been proposed that they consitute an ancient phylum, the Vendobionta, that largely died out just before the beginning of the Cambrian. A fern with simple (lobed or pinnatifid) blades, the dissection of each blade not quite reaching to the rachis. ... Rangeomorphs are soft-bodied creatures, neither animals nor plants that appeared 575 million years ago at the beginning of the Ediacaran period. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ... Classes Caudofoveata Aplacophora Polyplacophora - Chitons Monoplacophora Bivalvia - Bivalves Scaphopoda - Tusk shells Gastropoda - Snails and Slugs Cephalopoda - Squids, Octopuses, etc. ... Charles Darwin, father of the theory of evolution by natural selection. ... Phylum (plural: phyla) is a taxon used in the classification of animals. ... The Cambrian is a major division of the geologic timescale that begins about 542 million years before the present (BP) at the end of the Proterozoic eon and ended about 490 million years BP with the beginning of the Ordovician period. ...

Several supposed Vendian-like forms have been identified from the Cambrian, however many of these have since been redescribed as trace fossils or pseudofossils.

Well known Vendian forms include Arkarua, Charnia, Dickinsonia, Ediacaria, Marywadea, Onegia, Yorgia and Pteridinium. The full list runs to 100 or more taxa. Some of those named are rare but interesting for one reason or another. Others are widely distributed. Arkaruais a small, Precambrian disk-like fossil with a raised center, a number of radial ridges on the rim, and a five-pointed central depression marked with radial lines of 5 small dots from the middle of the disk center. ... Charnia is the genus name given to a frond-like Precambrian plant with segmented ridges branching alternately to the right and left from a zig-zag medial suture. ... Dickinsonia is an ancient ovoid fossil with somewhat radial tubes from a (sometimes missing) central ridge. ... Pteridinium is a fossil found in a number of Precambrian deposits worldwide. ... A taxon (plural taxa) is an element of a taxonomy, e. ...

External link

• Online exhibit at U. of California Museum of Paleontology
• The Ediacaran Biota page @ Paleos