{{Short description|Extinct genus of marine invertebrates}} {{Speciesbox | fossil_range = Late Ediacaran<br> ~{{fossil range|547.4}} | image = Protechiurus_3D_Reconstruction.png | image_caption = 3D reconstruction of ''Protechiurus edmondsi'' | genus = Protechiurus | parent_authority = Glaessner, 1979 | species = edmondsi | authority = Glaessner, 1979<ref name="Glaessner1979"/> | synonyms = * ✝''Vendoglossa'' {{small|Seilacher, 2007}}<ref name="Seilacher_2007">{{cite book|last=Seilacher|first=A.|year=2007|chapter=The nature of vendobionts|editor1-last=Vickers-Rich|editor1-first=P.|editor2-last=Komarower|editor2-first=P.|title=The Rise and Fall of the Ediacaran Biota|series=Geological Society of London Special Publications|volume=286|pages=387–397|doi=10.1144/SP286.28}}</ref><ref name="Ivantsov_2019">{{cite journal | author = Ivantsov, A. Yu. | author2 = Vickers-Rich, P. | author3 = Zakrevskaya, M. A. | author4 = Hall, M. | year = 2019 | title = Conical Thecae of Precambrian Macroorganisms. | journal = Paleontological Journal | volume = 53 | issue = 11 | pages = 1134–1146 | url = https://www.researchgate.net/publication/339600498 | doi = 10.1134/S0031030119110054 | s2cid = 212642725 }}</ref> * ✝''V. tuberculata'' {{small|Seilacher, 2007}} }}
'''''Protechiurus''''' is an extinct conical organism from the Ediacaran Nama Group in Namibia. First interpreted as a echiurid worm, it is now interpreted as a cnidarian. It is a monotypic genus, containing only ''Protechiurus edmondsi''.
== Discovery == Fossil material of ''Protechiurus'' was discovered in the Aar Farm Member of the Dabis Formation, Kuibis Quartzite, in the Nama Group, Namibia in 1963, and was formally described and named in 1979.<ref name="Glaessner1979">{{Cite journal | last1 = Glaessner | first1 = M. F. | title = An echiurid worm from the Late Precambrian | doi = 10.1111/j.1502-3931.1979.tb00991.x | journal = Lethaia | volume = 12 | issue = 2 | pages = 121–124 | year = 1979 }}</ref><ref name="Ivantsov2019">{{cite journal |last1=Ivantsov |first1=A. Yu. |last2=Vickers-Rich |first2=P. |last3=Zakrevskaya |first3=M. A. |last4=Hall |first4=M. |title=Conical Thecae of Precambrian Macroorganisms |journal=Paleontological Journal |date=December 2019 |volume=53 |issue=11 |pages=1134–1146 |doi=10.1134/S0031030119110054}}</ref>
== Etymology == The generic name ''Protechiurus'' derives from the Greek word ''protos'', to mean "first"; and the generic name ''Echiurus'', a genus of spoon worm. The specific name derives from the Latinised surname of Dr. Stanley Joe Edmonds of the Department of Zoology, University of Adelaide and South Australian Museum.<ref name="Glaessner1979"/>
== Description == thumb|left|200px|Size chart of ''Protechiurus edmondsi''. ''Protechiurus edmondsi'' is an elongated, hexahedral organism, growing up to {{cvt|74|mm|1}} in length and with a width of {{cvt|19|mm|1}} at its widest point. It is considerably narrow at one end and wide at the other, previously interpreted as the anterior and posterior ends respectively as an echiurid worm, now interpreted as the closed and open ends respectively as a tubular cnidarian.<ref name="Glaessner1979"/><ref name="Ivantsov2019"/> The body is also noted to be compressed, which may have been due to the body being made of an elastic material, along with six longitudinal ridges on the body, with the ones on the flatter sides being more prominent, although do not feature plates like ''Vendoconularia''.<ref name="Glaessner1979"/><ref name=Dzik03>{{Cite journal |last1=Dzik |first1=Jerzy |date=2003 |title=Anatomical Information Content in the Ediacaran Fossils and Their Possible Zoological Affinities |journal=Integrative and Comparative Biology |volume=43 |issue=1 |pages=114–126 |doi=10.1093/icb/43.1.114 |pmid=21680416|doi-access=free }}</ref><ref name="Ivantsov2019"/> Although more poorly preserved, there are also transverse lines along the length of the body, being tuberculate in shape.<ref name="Ivantsov2019"/>
== Affinities == When originally described in 1979 by Martin Glaessner, the overall appearance of the ''Protechiurus'' saw it being assigned to the worm phylum Echiura, with the thinner end of the fossil being seen as a proboscis, and the longitudinal ridges being a feature only known to echiurid worms.<ref name="Glaessner1979"/> In 1994, ''Protechiurus'' was then placed as a "vendobiont", alongside other similar bag-like organisms such as ''Ernietta'' and ''Pteridinium'', in support of the Ediacaran fauna representing a distinct phylum, separate from modern phyla seen today.<ref name="Buss1994">{{Cite journal | last1 = Buss | first1 = L. W. | last2 = Seilacher | first2 = A. | title = The Phylum Vendobionta: A Sister Group of the Eumetazoa? | journal = Paleobiology | volume = 20 | issue = 1 | pages = 1–4 | doi = 10.1017/S0094837300011088| year = 1994 | s2cid = 89131248 }}</ref> Later, in 2003, the placement as an ecdysozoan was then suggested for ''Protechiurus'', again based on the appearance of the then singular fossil.<ref name=Dzik03/> In 2007, a new fossil had been found from the same locality as ''Protechiurus'', ''Vendoglossa tuberculata'', a flattened fossil with longitudinal ridges and transverse lines, and similar in overall shape.<ref name="Seilacher_2007"/> During the description of this then separate organism, other palaeontologists had suggested that ''Protechiurus'' may in fact be a proto-chordate, whilst others, like Bruce Runnegar, suggested it to possibly be a dubiofossil.<ref name="The Rise of Animals">{{Cite book|url=https://books.google.com/books?id=KsFFIrJ8IxEC&dq=Protechiurus&pg=PA283|title=The Rise of Animals: Evolution and Diversification of the Kingdom Animalia|first1=Mikhail A.|last1=Fedonkin|first2=James G.|last2=Gehling|first3=Kathleen|last3=Grey|first4=Guy M.|last4=Narbonne|first5=Patricia|last5=Vickers-Rich|date=Mar 16, 2007|publisher=JHU Press|isbn=9780801886799|access-date=June 27, 2022|via=Google Books}}</ref>
This all came to a head in 2019, when Ivantsov et al. had decided to not only restudy ''Protechiurus'', but also the previously described ''Vendoglossa'' and ''Vendoconularia''. They had noted many similarities between all organisms, from the general conical morphology, longitudinal ridges to transverse lines. Here the researchers synonymised ''Vendoglossa'' with ''Protechiurus'', and erected a new family, Protechiuridae, which they postured may be a basal group to the cnidarian scyphozoans, being ancestral to both the conulariids and anabaritids, two families that share a similar appearance to the protechiurids like ''Protechiurus'' with tubular to conical bodies.<ref name="Ivantsov2019"/> Subsequent studies done after have noted that whilst a more detailed analysis is needed for ''Protechiurus'' to confidentially place it next to ''Vendoconularia'' phylogenetically, it does give support for ''Protechiurus'' (and ''Vendoconularia'') possibly being a stem-group conulariid.<ref>{{cite journal |last1=Sarsembaev |first1=Zhiger A. |last2=Marusin |first2=Vasiliy V. |title=Nonmineralized triradial conulariids from the lowermost Cambrian Stage 2 of the Olenek Uplift, Siberian Platform |journal=Journal of Paleontology |date=July 2022 |volume=96 |issue=4 |pages=791–802 |doi=10.1017/jpa.2022.21}}</ref>
==See also== *''Vendoconularia'' *List of Ediacaran genera
==References== {{Reflist}}
{{Taxonbar|from=Q7251233}}
Category:Ediacaran life Category:Ediacaran first appearances Category:Enigmatic prehistoric animal genera Category:Fossils of Namibia Category:Monotypic prehistoric animal genera