Ediacara biota

As Ediacaran fauna summary of the extinct multicellular creatures ( Metabiota ) from the time of the late Proterozoic be called before about 585-542 million years. The imprints of the soft body of these creatures in the sedimentary rock from a time before the development of mineral, fossil preservation efficient hard parts were first found in the South Australian Ediacaran hills. It is often thought that it might have acted as primitive precursor of the animals as some of the forms are similar to those of later animals, but this is not clarified.

The importance of the Ediacaran fauna

A few decades ago it was assumed that there were multicellular creatures only since the Cambrian period about 542 million years, as developed only since that time are hard parts ( " Cambrian explosion "). This view was qualified by the discovery of much older Ediacaran biota. There, the lifts were from 2 to 80 centimeters long, clearly structured organisms in sandstones found that had been deposited at the bottom of a shallow Precambrian sea. The discovery of soft organisms that looked like jellyfish and worms, therefore, led to a complete reinterpretation of the fossil record of multicellular organisms, and the evolution of life. The last age of the Neoproterozoic is called due to the great importance of the Ediacaran fauna Ediacaran.

The Ediacaran is a long evolutionary period in which between highly developed multicellular organisms, there was an ecological balance without predator-prey relationships. The Ediacaran fauna consists of soaked piece organisms without apparent offensive or defensive organs and without eating tools, no fossils have been found with bite marks.

It prints animal organisms such as sponges ( Porifera ), hydroids ( Hydrozoa ), screen Jellyfish ( Scyphozoa ), anemones ( Anthozoa ), Protomedusen, Vendobionten ( " filled with mucus quilted air mattress " ) and the like a sea pen looking Charniodiscus were found. Another group of Ediacaran fossils fauna are trace fossils. So, in many Ediacaran deposits evidence of crawling and shallow plowing the sediment. A spiral track, which was found in the Ediacaran hills, is interpreted as the grazing of a surface by an animal.

The dominated skeleton bearing animals living world of the early Phanerozoic after the so-called Cambrian explosion is significantly different from that of the Ediacarian, although individual representatives have survived until the Cambrian. However, it is controversial whether the known representatives of these often quite strange acting fauna to the ancestors later live animals, nor if they became extinct without descendants.


There are in the art several attempts to reconstruct the Ediacara scenario. It is discussed, among other things, a shallow-water habitat with a disproportionate stocking by jellyfish and sea pens. Most creatures probably lived on the ground and were either sessile or mobile. Evidence points out that, for example, in Namibia, the communities are allochthonous, that is, they were stranded at the deposition site. Most of the fossils found are considered as autochthonous, which it says were creatures communities that have been embedded in place. The trace fossils have been found to be a part associated organisms for which body fossils.

Sites of the Ediacaran fauna

The geologist Reginald Sprigg Claude explored in 1946, the Ediacaran hills north of Adelaide. There he found imprints of soft organisms that had survived mainly on the underside of quartzite and sandstone slabs. It was the first comprehensive fund Precambrian fossils. A few years later fossils were discovered by soft bodied organisms, also in Leicestershire, UK, as well as in Namibia. Fossils of the Ediacaran type known today among other things, from the region of the White Sea in Russia, from Newfoundland, Canada's Northwest Territories, the U.S. state of North Carolina, Ukraine and China. All findings are from a period before 670 million to 540 million years ago.

As it turned out later, the first fossil of the Ediacaran fauna ( Aspidella ) of Elkanah Billings was described in 1872 in Canada.