Ediacaran

views updated May 29 2018

Ediacaran The last (i.e. youngest) faunal stage of the Precambrian; it is marked by the presence, at localities all over the world, of the distinctive Ediacaran fauna, named after a site at Ediacara in South Australia. Ediacaran fossils come from a shallow, littoral, marine environment and the animals appear to have been stranded on mud-flats or in tidal pools. About 30 genera are known and include: medusoids (jellyfish, e.g. Medusina mawsoni and Medusinites); pennatulaceans (soft corals, e.g. Charniodiscus); and annelid worms (e.g. Dickinsonia and Spriggina). There are also ovoid or discoid forms of unknown affinity. Since the fossils were first described by Martin Glaessner in 1961, similar faunal types of equivalent age have been found elsewhere in the world.

Ediacaran

views updated May 23 2018

Ediacaran The last (i.e. youngest) faunal stage of the Proterozoic; it is marked by the presence, at localities all over the world, of the distinctive Ediacaran fauna, named after a site in South Australia.