Ediacaria

Ediacaria is a fossil genus dating to the Ediacaran Period of the Neoproterozoic Era. Unlike most Ediacaran biota which disappeared almost entirely from the fossil record at the end of the Period, "Ediacaria" fossils have been found dating from the Baikalian age (850–650 Ma) of the Upper Riphean to 501 million years ago, well into the Cambrian Period. "Ediacaria" consists of concentric rough circles, radial lines between the circles and a central dome, with a diameter from 1 to 70 cm.
Systematics and taxonomy.
"Ediacaria" was named by Reg Sprigg in 1947, after the Ediacara Hills in South Australia. Two species are recognised: "E. flindersi", described by Sprigg from the Pound Quartzite in the Ediacara Hills, and "E. booleyi", described in 1995 from a Late Cambrian deposit at Booley Bay (County Wexford), Ireland. The species were named after the Flinders Ranges and Booley Bay, respectively.
"Ediacaria" is possibly a synonym for "Aspidella terranovica" described in 1872. Although "Ediacaria" is one of the first described organisms from the Precambrian, "Aspidella" was described earlier, although its age was not understood to be Precambrian. As "Aspidella" is apparently a form taxon, "Ediacaria" may yet be valid and denote one specific genus among several that seem to make up "Aspidella". "Spriggia wadea" is quite likely a synonym of "Ediacaria" (and consequently, possibly "Aspidella"); the differences seem to be merely due to different substrate in which the animals were embedded. (Gehling "et al." 2000)
"Ediacaria" was often classified as a jellyfish (a Scyphozoan Cnidarian), and has also been interpreted in many of the categories postulated to house the Ediacaran biota. A conspicuous filamentous microstructure preserved in some pyritised specimens suggests that it may have been a microbial colony, which disrupted the surrounding microbial mat to create the distinctive pattern (Grazhdankin, in press).