Ernietta
Species: E. plateauensis
Age and Location: Ediacaran of Namibia
Classification: ?Eukarya incertae sedis: Erniettomorpha
Ernietta is an iconic Ediacaran organism, and like most such organisms, its phylogenetic affinities are totally unknown, although like many other Ediacaran organisms, it may well be a stem-group animal. All we know for sure was that it was multicellular, but not apparently similar to any living multicellular organisms. A trait that defines the ‘erniettomorph’ body plan is a body The body of Ernietta was composed of essentially undifferentiated tubes of tough organic material. It appears to have lived mostly buried in the sand, with two fan-like fronds projecting into the water. Members of the genus seem to have lived together in large groups, perhaps as a consequence of their mode of reproduction.
Unlike all extant macroscopic organisms and like many other Ediacaran organisms, Ernietta probably were osmotrophic--that is, they fed exclusively by passively absorbing nutrients from the water around them. This was possible as a result of its being essentially a sediment-filled bag, so that most of its body volume was actually just sand. The tubes that comprised the fan-like structures probably primarily served in osmotrophy while the others were structural and served to anchor the organism, however, there is no clear morphological distinction between different body regions.
Sources:
Ivantsov AY., Narbonne GM., Trusler PW., Greentree C., Vickers-Rich P. 2015. Elucidating Ernietta: new insights from exceptional specimens in the Ediacaran of Namibia. Lethaia.
Laflamme M., Xiao S., Kowalewski M. 2009. Osmotrophy in modular Ediacara organisms. Proceedings of the National Academy of Sciences 106.