Editing Pteridinium

{{Short description|Ediacaran fossil}}
{{Automatic taxobox
| fossil_range = [[Ediacaran]], {{fossil range|558|543|ref=<ref name="Chen2014">{{cite journal | last1 = Chen | first1 = Zhe | last2 = Zhou | first2 = Chuanming | last3 = Xiao | first3 = Shuhai | last4 = Wang | first4 = Wei | last5 = Guan | first5 = Chengguo | last6 = Hua | first6 = Hong | last7 = Yuan | first7 = Xunlai | date = 2014 | title = New Ediacara fossils preserved in marine limestone and their ecological implications | journal = Scientific Reports | volume = 4 | page = 4180 | doi = 10.1038/srep04180 | pmid=24566959 | pmc=3933909| bibcode = 2014NatSR...4E4180C }}</ref>}}
| image = Pteridinium simplex.jpg
| image_caption = Fossil of ''Pteridinium simplex'' at the Senckenberg Museum, Frankfurt.
| taxon = Pteridinium
| authority = [[Georg Gürich|Gürich]], [[1933 in paleontology|1933]]
| synonyms = 
*''Pteridium'' <small>Gürich, [[1930 in paleontology|1930]]</small>
*''Onegia'' <small>Sokolov, 1976</small>
*''Archangelia'' <small>Fedonkin, 1979</small>
*''Inkrylovia'' <small>Fedonkin, 1979</small>
| synonyms_ref = <ref name="fossilworks">{{fossilworks |id=4722 |title=''Pteridinium'' |date=23 February 2024}}</ref>
| subdivision_ranks = Species
| subdivision =
* ''P. simplex'' <small>(Gürich, 1930)</small> ([[type species]])
* ''P. carolinaensis'' <small>(St. Jean, 1973)</small>
| subdivision_ref = <ref name="fossilworks"/>
}}

'''''Pteridinium''''' is an [[erniettomorph]] found in a number of [[Precambrian]] deposits worldwide. It is a member of the [[Ediacaran biota]].

==Body plan==
The three-lobed body is generally flat such that only two lobes are visible. Each lobe consists of a number of parallel ribs extending back to the main axis where the three lobes come together. Even on well-preserved specimens, there is no sign of a mouth, anus, eyes, legs, antennae, or any other appendages or organs.  The organism grew primarily by the addition of new units, probably at both ends, with the inflation of existing units contributing little to its growth.<ref name=Laflamme2009/>

==Ecology==
Specimens found in what is thought to be life positions indicate that the creature rested on, or possibly in, the [[sediment]] in shallow seas. No tracks are known that would seem to be consistent with a moving ''Pteridinium''. It is unclear whether it performed [[photosynthesis]], or osmotically extracted nutrients from seawater.<ref name='Laflamme2009'>{{Cite journal | last1 = Laflamme | first1 = M. | last2 = Xiao | first2 = S. | last3 = Kowalewski | first3 = M. | title = Osmotrophy in modular Ediacara organisms | journal = Proceedings of the National Academy of Sciences | volume = 106 | issue = 34 | pages = 14438–14443 | year = 2009 | doi = 10.1073/pnas.0904836106 
|bibcode = 2009PNAS..10614438L | pmid=19706530 | pmc=2732876| doi-access = free }}</ref>

==Occurrence==
Fossils are common in late Precambrian deposits in [[South Australia]], [[South Africa]], [[Namibia]], and the [[White Sea]] region of [[Russia]]. It has also been found in [[North Carolina]] and is reported from [[California]] and the [[Northwest Territories]] of [[Canada]].

==History==
''Pteridium simplex'' was originally described by [[Georg Gürich]] in 1930 published in ''Zeitschrift der Deutschen Geologischen Gesellschaft'' vol.82 p.&nbsp;637.  ''Pteridium'' was already used back in 1777 by [[Giovanni Antonio Scopoli|Scopoli]] as the generic name for [[bracken fern]], and so it was changed to "''Pteridinium''" in 1933.

Two ''Pteridinium'' specimens were found in North Carolina in 1963 by a high school student named John Brattain. After their discovery, they were misidentified by Joseph St. Jean from the [[University of North Carolina at Chapel Hill|UNC]] Geology Department as [[Cambrian]] [[trilobites]], and were classified as "''?[[Paradoxides]] carolinaensis''", until they were discovered to be a species of ''Pteridinium''.<ref>{{cite journal |last1=St Jean |first1=Joseph |title=A new Cambrian trilobite from the Piedmont of North Carolina |journal=American Journal of Science |volume=273-A |year=1973 |pages=196–216 |url=https://earth.geology.yale.edu/~ajs/1973/ajs_273A_11.pdf/196.pdf }}</ref>

It was originally thought that ''Pteridinium'' might be a primitive [[Cnidaria]]n, but it appears that it is, at best, only very distantly related to any known cnidarian. Its relation to other known [[Ediacaran biota]] is not clear. There are no identified related forms, although there is some vague resemblance to other [[Ediacaran]] forms such as ''[[Dickinsonia]]'' and ''[[Spriggina]]'' that share some of its enigmatic characteristics, such as the "staggered" or [[glide symmetry]] of its units, or triradial symmetry otherwise only seen in [[trilobozoa]]ns like ''[[Tribrachidium]]''. ''Pteridinium'' has no known descendants.

==See also==
* [[List of Ediacaran genera]]

==References==
{{Reflist}}

==Further reading==

* {{cite journal |last1=Meyer |first1=Mike |last2=Elliott |first2=David |last3=Wood |first3=Andrew D. |last4=Polys |first4=Nicholas F. |last5=Colbert |first5=Matthew |last6=Maisano |first6=Jessica A. |last7=Vickers-Rich |first7=Patricia |last8=Hall |first8=Michael |last9=Hoffman |first9=Karl H. |last10=Schneider |first10=Gabi |last11=Xiao |first11=Shuhai |title=Three-dimensional microCT analysis of the Ediacara fossil Pteridinium simplex sheds new light on its ecology and phylogenetic affinity |journal=Precambrian Research |date=1 August 2014 |volume=249 |pages=79–87 |doi=10.1016/j.precamres.2014.04.013 |bibcode=2014PreR..249...79M }}

==External links==
* [http://www.ucmp.berkeley.edu/vendian/pteridinium.html Vendian Animals: ''Pteridinium''], at University of California Museum of Paleontology
* [http://www.ucmp.berkeley.edu/vendian/pter.gif Photograph]

{{Taxonbar|from=Q680300}}

[[Category:Ediacaran life]]
[[Category:White Sea fossils]]
[[Category:Prehistoric animal genera]]
[[Category:Fossil taxa described in 1930]]