Ediacaran

Ediacara +‎ -an After the Ediacara Hills in South Australia; from an Australian Aboriginal term (details disputed). See Ediacara Hills#Word origin on Wikipedia.Wikipedia

• (UK) IPA^(key): /ɛdiˈakəɹən/

Ediacaran (comparative more Ediacaran, superlative most Ediacaran)

1. (geology) Of a geologic period within the Neoproterozoic era from about 620 to 542 million years ago. [from 20th c.]
   • 1992, Richard J. F. Jenkinsm, Chapter 5: Functional and Ecological Aspects of Ediacaran Assemblages, Jere H. Lipps, Philip W. Signor (editors), Origin and Early Evolution of the Metazoa, page 133,

     The widespread discoveries of fossil remains of Ediacaran aspect have generated continued excitement in respect of their possible evolutionary significance, and in terms of recent surrealistic interpretations of their morphology and inferred interrelationships (Pflug, 1970a,b, 1972a,b; Fedonkin, 1985 a,b; Gould, 1984, 1985; Seilacher, 1984, 1985, 1989; McMenamin, 1986; and Bergstrom, 1989, 1990), a reexamination of the actual fossil material is timely.

   • 2007, Clarence A. Hall, Jr., Introduction to the Geology of Southern California and Its Native Plants, page 83,

     Swartpuntia (frondlike metazoans) and Ernietta (ribbed saclike metazoans) are part of the Ediacaran fauna.

   • 2011, Matt Cartmill, Fred H. Smith, The Human Lineage, page 18,

     Then in 1946, fossils of multicellular organisms were recovered from Vendian deposits around 570My old at the Ediacara copper mine in South Australia. Since then, geologists have found similar Ediacaran faunas in Precambrian rocks from other parts of the world as well.

Ediacaran

1. (geology) The Ediacaran period. [from 20th c.]
   • 2008, Doug Macdougall, Nature’s Clocks: How Scientists Measure the Age of Almost Everything‎, page 145:

     Recently, in 2004, a new geological period, the Ediacaran, was formally added to the time scale. It immediately precedes the Cambrian period, and therefore lies within the Proterozoic.

   • 2011, Guido O. Perez, Methodological Naturalism and Planetary Humanism‎, page 18:

     They became prevalent during the Ediacaran, 635 to 542 million years ago.

   • 2012, Ivan R. Schwab, Richard R. Dubielzig, Charles Schobert, Evolution's Witness: How Eyes Evolved, page 25,

     Metazoan life was in full swing by the early phases of the Ediacaran, approximately 650 million years ago, but these first steps were small aggregations of cells with little more than eyespots or early cups of pigment lined with photoreceptive cells.

Ediacaran (plural Ediacarans)

1. An organism that lived in the Ediacaran period. [from 20th c.]
   • 2016, Peter Godfrey-Smith, Other Minds, William Collins 2018, p. 30:

     Many Ediacarans seem to have lived quiet lives of very limited mobility on the bottom of the sea.

• Appendix:Geologic timescale