Ediacaran biota consists of all life forms that were present on Earth during the Ediacaran Period. These were composed of tubular and frond-shaped, mostly sessile, organisms. This biota largely disappeared with the rapid increase in biodiversity known as the Cambrian explosion. Most of the currently existing body plans of animals first appeared in the fossil record of the Cambrians.
About Ediacaran biota in brief
Ediacaran biota consists of all life forms that were present on Earth during the Ediacaran Period. These were composed of tubular and frond-shaped, mostly sessile, organisms. This biota largely disappeared with the rapid increase in biodiversity known as the Cambrian explosion. Most of the currently existing body plans of animals first appeared in the fossil record of the Cambrians rather than the Ediakaran. The concept of Ediacarans is somewhat artificial as it cannot be defined geographically, stratigraphically, taphonomically, or biologically. It is not even established that they were animals, with suggestions they were lichens, algae, protists known as foraminifera, fungi or microbial colonies. A 2018 study confirmed that one of the period’s most-prominent and iconic fossils, Dickinsonia, included cholesterol, suggesting affinities to animals, fungi, or red algae. It was not until the discovery of the iconic Charnia pre-Cambrian rocks that some serious attention was given to the period. The fossils were believed to be Early Cambrian, but these rocks were so old they were not seriously considered to be so early. In 1946, no link to Aspidella was made and no link was made to Charnian rocks. In 2003, a study found that the Charnians were in fact from the early Ediacara Hills of South Australia and the White Sea, Russia. The discovery sparked some serious interest, but not so much that it was considered seriously to be early Cambrian. The fossil community of the Flinders Flinders Ranges was found in Australia’s Flinders Hills in the 1990s.
A diverse EdiacCaran community was discovered in 1995 in Sonora, Mexico, and is approximately 555 million years in age, roughly coeval with Ediacaren fossils of the Ediaara Hills, South Australia. The Ediaccarans are the earliest known complex multicellular organisms. The Cambrian biota may have undergone evolutionary radiation in a proposed event called the Avalon explosion, 575 million years ago. This was after the Earth had thawed from the Cryogenian period’s extensive glaciation. Multiple hypotheses exist to explain the disappearance of this biota, including preservation bias, a changing environment, the advent of predators and competition from other life-forms. If these enigmatic organisms left no descendants, their strange forms might be seen as a \”failed experiment\” in multice cellular life. One palaeontologist proposed a separate kingdom level category Vendozoa in the Linnaean hierarchy for the Edian biota. The morphology and habit of some taxa suggest relationships to Porifera or Cnidaria, and other organisms have been thought to possess bilateral symmetry, although this is controversial. Recent sampling of late Ediacarin strata across Baltica suggests the flourishing of the organisms coincided with conditions of low overall productivity with a very high percentage produced by bacteria, which may have led to high concentrations of dissolved organic material.