Parvancorina

The generic name is derived from a crasis compound word from the Latin parva ancora (small anchor).

The specific name of the type species, P. minchami, honors Mr. H. Mincham, the private collector, who in 1957 had collected and presented a number of fine specimens of Ediacaran fossils to the South Australian Museum.

The specific name of P. sagitta is the Latin word sagitta (arrow), in direct reference to the arrow-like shape.

P. minchami fossils were first discovered in the Ediacara Member of the Rawnslay Quartzite, Flinders Ranges, in South Australia.{{Cite journal | author = Glaessner, Martin F. | year = 1958 | url = http://www.samuseum.sa.gov.au/Journals/TRSSA/TRSSA_V081/TRSSA_V081_p185p188.pdf | title = New Fossils from the Base of the Cambrian in South Australia | journal = Transactions of the Royal Society of South Australia | volume = 81 | pages = 185–188 | url-status = dead | archiveurl = https://web.archive.org/web/20070929094012/http://www.samuseum.sa.gov.au/Journals/TRSSA/TRSSA_V081/TRSSA_V081_p185p188.pdf | archivedate = 2007-09-29 }} This species is also known from deposits of the Verkhovka, Zimnegory and Yorga Formations in the White Sea area of the Arkhangelsk Region, Russia. Additionally, similar poorly preserved Parvancorina sp. fossils were found in the Lyamtsa Formation of this Russian region. This Species is also recorded from Sursager area in Jodhpur region, Sonia Formation of Marwar Supergroup in India.{{Cite journal |last=Parihar, Virendra S.; Chouhan, Hukma R.; Kumar, P.; Harsh |first=A. |date=2023 |title=The anchor-shaped Ediacaran organism Parvancorina from Marwar Supergroup, India |url=https://link.springer.com/article/10.1007/s12040-023-02205-y |journal=Journal of Earth System Science |volume=132 |issue=187 |pages=1-9 |doi=10.1007/s12040-023-02205-y |via=}}

P. sagitta is found in the Verkhovka formation on the Solza River, White Sea area of the Arkhangelsk Region, Russia.{{cite journal | author = Ivantsov, A.Y. | author2 = Malakhovskaya, Y.E. | author3 = Serezhnikova, E.A. | year = 2004 | title = Some Problematic Fossils from the Vendian of the Southeastern White Sea Region | journal = Paleontological Journal | volume = 38 | issue = 1 | pages = 1–9 | url = http://www.vend.paleo.ru/pub/Ivantsov_et_al_2004_eng.pdf | url-status = dead | archiveurl = https://web.archive.org/web/20070704183946/http://www.vend.paleo.ru/pub/Ivantsov_et_al_2004_eng.pdf | archivedate = 2007-07-04 }}

File:Parvancorina.jpg

File:Parvancorina minchami - MUSE.jpg in Trento, Italy]]

It has a raised ridge down the central axis of symmetry. This ridge can be high in unflattened fossils. At the 'head' end of the ridge there are two quarter-circle-shaped raised arcs attached. In front of this are two nested semicircular lines.

The fossils are normally about {{convert|1|cm|abbr=off}} in each of width and length, but can be up to {{convert|3.0|cm|abbr=off}}.

In attempting to determine its phylogenic relationships, Parvancorina has been compared with trilobite-like arthropods, such as Skania from the Burgess Shale Biota, Canada, and Primicaris from the Chengjiang Biota, China.{{cite journal |doi=10.1080/08912960500508689 |title=A Parvancorina-like arthropod from the Cambrian of South China |journal=Historical Biology |volume=18 |issue=1 |pages=33–45 |year=2006 |last1=Lin |first1=Jih-Pai |last2=Gon |first2=Samuel M |last3=Gehling |first3=James G |last4=Babcock |first4=Loren E |last5=Zhao |first5=Yuan-Long |last6=Zhang |first6=Xing-Liang |last7=Hu |first7=Shi-Xue |last8=Yuan |first8=Jin-Liang |last9=Yu |first9=Mei-Yi |last10=Peng |first10=Jin |s2cid=85821717 }}{{cite journal

| last1= Glaessner |first1=M. F.

| year = 1980

| title = Parvancorina - an Arthropod from the Late Precambrian Fauna of the Ediacara Fossil Reserve

| journal = Records of the South Australian Museum

| volume = 13

| pages = 83–90

| url = http://www.biologiezentrum.at/pdf_frei_remote/ANNA_83_0083-0090.pdf

}}

However, the growth form of Parvancorina is unusual for an arthropod.{{cite journal |doi=10.1134/S003103010901002X |title=Growth variability in the late Vendian problematics Parvancorina Glaessner |journal=Paleontological Journal |volume=43 |issue=1 |pages=12–8 |year=2009 |last1=Naimark |first1=E. B |last2=Ivantsov |first2=A. Yu |s2cid=83863648 }} Furthermore, the strong resemblance of P. sagitta to the primitive mollusk-like bilateran Temnoxa and similarities to parts of Kimberella{{cite journal |doi=10.1666/13-072 |title=Patterns of Evolution of the Ediacaran Soft-Bodied Biota |journal=Journal of Paleontology |volume=88 |issue=2 |pages=269–83 |year=2015 |last1=Grazhdankin |first1=Dmitriy |s2cid=129317326 }} casts further doubt on an arthropod affinity.

Parvancorina typically lived with their "heads" parallel to the current direction.{{cite journal |doi=10.1098/rsbl.2017.0033 |pmid=28515329 |pmc=5454237 |title=Inference of facultative mobility in the enigmatic Ediacaran organism Parvancorina |journal=Biology Letters |volume=13 |issue=5 |pages=20170033 |year=2017 |last1=Darroch |first1=Simon A. F |last2=Rahman |first2=Imran A |last3=Gibson |first3=Brandt |last4=Racicot |first4=Rachel A |last5=Laflamme |first5=Marc }} Overfolding of the fossils from all sides contradicts any form of stalked attachment to the sea floor.{{cite journal |doi=10.1038/srep45539 |pmid=28358056 |pmc=5371987 |title=Rheotaxis in the Ediacaran epibenthic organism Parvancorina from South Australia |journal=Scientific Reports |volume=7 |pages=45539 |year=2017 |last1=Paterson |first1=John R |last2=Gehling |first2=James G |last3=Droser |first3=Mary L |last4=Bicknell |first4=Russell D. C |bibcode=2017NatSR...745539P }} They are suggested to have been mobile and able to actively orientate their bodies towards the current direction, with smaller individuals from the Ediacara biota in Australia often found in close association with each other.{{Cite journal |last=Coutts |first=Felicity J. |last2=Bradshaw |first2=Corey J.A. |last3=García-Bellido |first3=Diego C. |last4=Gehling |first4=James G. |date=March 2018 |title=Evidence of sensory-driven behavior in the Ediacaran organism Parvancorina: Implications and autecological interpretations |url=https://linkinghub.elsevier.com/retrieve/pii/S1342937X17303544 |journal=Gondwana Research |language=en |volume=55 |pages=21–29 |doi=10.1016/j.gr.2017.10.009}} They have been proposed to be filter feeders, using their body ridges to direct water towards feeding structures, with deposit feeding being a possible but less likely ecology.

{{Portal|Paleontology}}

• List of Ediacaran genera

• [http://www.ediacaran.org/parvancorina.html Ediacaran.org]
• [http://www.peripatus.gen.nz/Paleontology/EdiBiota.html Peripatus]
• [http://www.trilobites.info/origins.htm Trilobites.info]
• [https://mary-droser.squarespace.com/tribrachidium-1/ Home of the Ediacaran]
• {{cite journal |doi=10.1016/j.gr.2017.10.009 |title=Evidence of sensory-driven behavior in the Ediacaran organism Parvancorina : Implications and autecological interpretations |journal=Gondwana Research |volume=55 |pages=21–29 |year=2017 |last1=Coutts |first1=Felicity J |last2=Bradshaw |first2=Corey J.A |last3=García-Bellido |first3=Diego C |last4=Gehling |first4=James G |bibcode=2018GondR..55...21C |url=https://dspace.flinders.edu.au/xmlui/bitstream/2328/37851/1/Coutts_Evidence_AM2017.pdf |hdl=2328/37851 |hdl-access=free }}

{{Taxonbar|from=Q763329}}

Category:Ediacaran life

Category:Enigmatic prehistoric animal genera

Category:White Sea fossils

Category:Fossil taxa described in 1958