Temporal range: Precambrian
|Impressions of Nemiana simplex from Ukraine|
Nemiana is a genus of simple, sessile organisms, containing just one species, N. simplex. They are one of the most commonly found Ediacaran organisms. While they have been found worldwide, their main locality are the sandstone shales near the White Sea, Russia. 
Nemiana simplex has given taxonomists great trouble due to its simple nature. When the species was first discovered it was placed in incertae sedis, however since then, a combination of well-preserved specimens and new techniques that have allowed scientists to examine the creature's body structure, have given the creature anatomical links to jellyfish and was subsequently placed in with the other extinct coelenterates. It has been suggested that N. simplex is in fact related to the protoctists and is sometimes thought to be simply a conglomeration of green algae similar to a stromatolite, however, this theory is disputed. 
Nemiana simplex has one of the most simple body plans of all Ediacarans. It consists of a jelly-like sac filled with its various internal structures. However some fossils possess strange markings on top which suggests that the species had small tentacles. 
Lifestyle and reproduction
It is possible that this creature did move and fed upon the algal mats of the precambrian oceans. However most scientists agree that this creature was in fact more similar to a sea anemone and burrowed, leaving its top half and hypothetical tentacles in the open water possibly for feeding. Scientists think that this organism reproduced asexually, but some believe that it released its zygotes into the water or produced spores or polyps. 
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- Палий В. М., Пости Е., Федонкин М. А. Мягкотелые Метазоа и ископаемые следы животных венда и раннего кембрия. В кн.: Палеонтология Верхнедокембрийских и кембрийских Отложений Восточно-европейской платформы. — М.: Наука, 1979.
- Maxim V. Leonov Comparative Taphonomy of Vendian Genera Beltanelloides and Nemiana as a Key to their Nature
- Mikhail A. Fedonkin The Rise of Animals: Evolution and Diversification of the Kingdom Animalia
- Paleobiology Database
- Patricia Vickers-Rich, Patricia Komarower The Rise and Fall of the Ediacaran Biota
- J. William Schopf Major Events in the History of Life