Proarticulata

Image:Proarticulata Classes.jpg

{{clear left}}

{{main|Vendiamorpha}}

The body is completely segmented, with all isomers curved towards the posterior, and the first isomer is normally much larger than the rest. The first two isomers at the anterior dorsal end are partly fused. (e.g., Vendia, Paravendia and Karakhtia).

{{cite journal

| last = Ivantsov | first = A.Yu.

| year = 2001

| title = Vendia and other precambrian "Arthropods"

| journal = Paleontological Journal

| volume = 35 | issue = 4 | pages = 335–343

| url = https://www.academia.edu/2605872

}}

{{cite journal

| last = Ivantsov | first = A.Yu.

| year = 2004

| title = New Proarticulata from the Vendian of the Arkhangel'sk Region

| journal = Paleontological Journal

| volume = 38 | issue = 3 | pages = 247–253

| url = http://vend.paleo.ru/pub/Ivantsov_2004_eng.pdf

| url-status = dead

| archive-url = https://web.archive.org/web/20070927022709/http://vend.paleo.ru/pub/Ivantsov_2004_eng.pdf

| archive-date = 2007-09-27

}}

{{cite journal

| last1 = Ivantsov | first1 = A.Yu.

| last2 = Malakhovskaya | first2 = Y.E.

| last3 = Serezhnikova | first3 = E.A.

| year = 2004

| title = Some problematic fossils from the Vendian of the south-eastern 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

| archive-url = https://web.archive.org/web/20070704183946/http://www.vend.paleo.ru/pub/Ivantsov_et_al_2004_eng.pdf

| archive-date = 2007-07-04

}}

{{cite conference

| last = Ivantsov | first = A.Yu.

| year = 2004

| title = Vendian animals in the phylum Proarticulata

| conference = The Rise and Fall of the Vendian Biota

| page = 52

| id = IGSP Project 493

| location = Prato, Italy

| url = https://www.monash.edu/__data/assets/pdf_file/0010/75655/ivantsov.pdf

}}

{{main|Cephalozoa}}

These proarticulatans are incompletely segmented, as the anterior zone is free of isomers, often making a "hairband" like appearance (example cephalozoans include Yorgia, Praecambridium, Andiva, Archaeaspinus, Ivovicia, Podolimirus, Tamga, Spriggina, Marywadea and Cyanorus).

{{cite journal

| last = Ivantsov | first = A.Yu.

| date = April 2007

| title = Small Vendian transversely articulated fossils

| journal = Paleontological Journal

| volume = 41 | issue = 2 | pages=113–122

| doi = 10.1134/S0031030107020013 | s2cid = 86636748

| url = https://www.academia.edu/2352394

}}

Some cephalozoans from the family Yorgiidae demonstrate pronounced asymmetry of the left and right parts of the body. For instance, Yorgia’s initial right isomer is the only one which spreads far towards the left side of the body. Archaeaspinus has an unpaired anterior lobe confined by the furrow to the left side only.

{{cite journal

| last = Ivantsov | first = A.Yu.

| year = 1999

| title = A new Dickinsoniid from the upper Vendian of the White Sea Winter Coast (Russia, Arkhangelsk region)

| journal = Paleontological Journal

| volume = 33 | issue = 3 | pages = 233–241

| url = https://www.academia.edu/2604893

}}

file:Cephalonega stepanovi.jpg stepanovi.illustration (c) Stanton F. Fink]]

file:Lossinia_lissetski.jpg feeding on surface algae.]]

In Cephalonega stepanovi and Tamga hamulifera the zone containing the isomers is encircled by a peripheral, undivided zone. The Cephalonega{{’}}s isomers are connected to each other, forming a body resembling a rubber raft; the Tamga{{’}}s isomers are separated from each other, and do not touch.

In Lossinia, the center undivided region has no visible isomers, instead having the lobe-like isomers emanate from the periphery of the undivided region as "transverse articulations."

{{main|Dipleurozoa}}

The dipleurozoan body is subradial, divided by isomers entirely (e.g., Dickinsonia and Phyllozoon). Dickinsonia juveniles show undivided anterior areas but these regions were reduced in the course of ontogeny, and in the adult stages Dickinsonia-like proarticulates changed so radically that they became almost indistinguishable from isomers.

{{cite journal

| last1 = Ivantsov | first1 = A.Yu.

| last2 = Malakhovskaya | first2 = Y.E.

| year = 2002

| title = Giant traces of Vendian animals

| journal = Doklady Earth Sciences

| volume = 385 | issue = 6 | pages = 618–622

| url = http://vend.paleo.ru/pub/Ivantsov_et_Malakhovskaya_2002-e.pdf

| url-status = dead

| archive-url = https://web.archive.org/web/20070704183947/http://vend.paleo.ru/pub/Ivantsov_et_Malakhovskaya_2002-e.pdf

| archive-date = 2007-07-04

}}

{{multiple image

| direction = vertical

| width = 145

| image1 = Andiva ivantsovi.jpg

| alt1 = Andiva ivantsovi

| caption1 = Andiva ivantsovi

----

| image2 = DickinsoniaCostata3.png

| alt2 = Dickinsonia costata

| caption2 = Dickinsonia costata

----

| image3 = Spriggina Floundensi 4.png

| alt3 = Spriggina floundersi

| caption3 = Spriggina floundersi

----

| image4 = Ovatoscutum_concentricium_cropped.png

| alt4 = Ovatoscutum concentricum

| caption4 = Ovatoscutum concentricum

----

| image5 = Yorgia.jpg

| alt5 = Yorgia waggoneri

| caption5 = Yorgia waggoneri

----

| image6 = Tamga_hamulifera.JPG

| alt6 = Tamga hamulifera

| caption6 = Tamga hamulifera

}}

• Armillifera Fedonkin, 1980{{cite journal| vauthors = Ivantsov AY | date=December 2010|title=Paleontological evidence for the supposed precambrian occurrence of mollusks| journal=Paleontological Journal| volume=40| issue=12| pages=1552–1559|doi=10.1134/S0031030110120105| s2cid=86523806}}

:A. parva Fedonkin, 1980

• Andiva Fedonkin, 2002{{Cite journal | vauthors = Fedonkin MA | title = Andiva ivantsovi gen. et sp. n. and related carapace‐bearing Ediacaran fossils from the Vendian of the Winter Coast, White Sea, Russia | doi = 10.1080/11250000209356456 | journal = Italian Journal of Zoology | volume = 69 | issue = 2 | pages = 175–181 | year = 2002 | s2cid = 85352552 | doi-access = free }}

:A. ivantsovi Fedonkin, 2002

• Archaeaspinus Ivantsov, 2007 (=Archaeaspis Ivantsov, 2001)

:A. fedonkini Ivantsov, 2001

• Cephalonega Ivantsov et al., 2019{{Cite journal| vauthors = Ivantsov AY, Fedonkin MA, Nagovitsyn AL, Zakrevskaya MA |year=2019 |title=Cephalonega, a new generic name, and the system of Vendian Proarticulata |journal=Paleontological Journal |volume=53 |issue=5 |pages=447–454 |doi= 10.1134/S0031030119050046|s2cid=203853224 |url=https://elibrary.ru/item.asp?id=39324149 |url-access=subscription }}

:C. stepanovi (Fedonkin, 1976)

• Chondroplon Wade, 1971 (possible =Dickinsonia)

:C. bilobatum Wade, 1971

• Cyanorus Ivantsov, 2004

:C. singularis Ivantsov, 2004

• Dickinsonia Sprigg, 1947

:D. costata Sprigg, 1947

:D. menneri Keller 1976 (=Vendomia menneri Keller 1976{{cite journal | vauthors = Keller BM, Fedonkin MA | year = 1976 | title = New Records of Fossils in the Valdaian Group of the Precambrian on the Syuz'ma River | journal = Izvestiya Akademii Nauk SSR | series = Seriya Geologicheskaya | volume = 3 | pages = 38–44 | url = http://vend.paleo.ru/pub/Keller_Fedonkin_1976.pdf | language = ru | url-status = dead | archive-url = https://web.archive.org/web/20070927022652/http://vend.paleo.ru/pub/Keller_Fedonkin_1976.pdf | archive-date = 2007-09-27 }})

:D. tenuis Glaessner & Wade, 1966

• Ivovicia Ivantsov, 2007

:I. rugulosa Ivantsov, 2007

• Karakhtia Ivantsov, 2004

:K. nessovi Ivantsov, 2004

• Lossinia Ivantsov, 2007

:L. lissetskii Ivantsov, 2007

• Marywadea Glaessner, 1976

:M. ovata Glaessner & Wade, 1966

• Ovatoscutum Glaessner & Wade, 1966

:O. concentricum Glaessner & Wade, 1966

• Paravendia Ivantsov, 2004

:P. janae Ivantsov, 2001 (=Vendia janae Ivantsov, 2001)

• Podolimirus Fedonkin, 1983 (=Valdainia Fedonkin, 1983)

{{cite journal | last1 = Dzik | first1 = J. | last2 = Martyshyn | first2 = A. | year = 2015 | title = Taphonomy of the Ediacaran Podolimirus and associated dipleurozoans from the Vendian of Ukraine | journal = Precambrian Research | volume = 269 | pages = 139–146 | url = https://www.academia.edu/15860379 | doi = 10.1016/j.precamres.2015.08.015

}}

:P. mirus Fedonkin, 1983 (Valdainia plumosa Fedonkin, 1983)

• Praecambridium Glaessner & Wade, 1966

:P. siggilum Glaessner & Wade, 1966

• Spriggina Glaessner, 1958

:S. floundersi Glaessner, 1958

• Tamga Ivantsov, 2007

:T. hamulifera Ivantsov, 2007

• Vendia Keller, 1969

:V. sokolovi Keller, 1969

:V. rachiata Ivantsov, 2004

• ? Windermeria Narbonne, 1994

:W. aitkeni Narbonne, 1994{{cite journal | vauthors = Narbonne GM |date=May 1994|title=New Ediacaran fossils from the Mackenzie Mountains, Northwestern Canada|journal=Journal of Paleontology|volume=63|issue=3|pages=411–416|jstor=1306192|doi= 10.1017/S0022336000025816|s2cid=133215767 }}

• Yorgia Ivantsov, 1999

:Y. waggoneri Ivantsov, 1999

• Epibaion Ivantsov, 2002{{Cite journal | vauthors = Ivantsov AY | title = Feeding traces of Proarticulata — the Vendian metazoa | doi = 10.1134/S0031030111030063 | journal = Paleontological Journal | volume = 45 | issue = 3 | pages = 237–248 | date = May 2011 | s2cid = 128741869 | url = https://www.academia.edu/2394670}}

:E. axiferus Ivantsov, 2002.

:E. waggoneris Ivantsov, 2011. This is a trace of Yorgia waggoneri

:E. costatus Ivantsov, 2011. This is a trace of Dickinsonia costata

• Phyllozoon Jenkins & Gehling, 1978

:P. hanseni Jenkins & Gehling, 1978

{{Clear}}

• Articulata
• List of Ediacaran genera

{{reflist|25em}}

• [https://web.archive.org/web/20110725191154/http://www.complex-life.org/database Database of Ediacaran Biota] Advent of Complex Life

{{Proarticulata}}

{{Taxonbar|from=Q2566978}}

Category:Bilaterian phyla

Category:Vendobionta