Temporal range: Late Ediacaran, between 567–550 Ma
PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
N
Fossil of Dickinsonia costata
Fossil of Spriggina
Scientific classification
Domain:
Eukaryota
Kingdom:
Animalia
Phylum:
†Proarticulata Fedonkin, 1985
Classes and families
†Vendiamorpha Fedonkin, 1985
†Vendiidae Ivantsov
†Dipleurozoa Harrington & Moore, 1955
†Dickinsoniidae Harrington & Moore, 1955
†Cephalozoa Ivantsov. 2004
†Sprigginidae Glaessner, 1958
†Yorgiidae Ivantsov, 2001
For more taxa, see text
Proarticulata is a proposed phylum of extinct, near-bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits, and dates to approximately 567 to 550 million years ago.[1][2] The name comes from the Greek προ (pro-) = "before" and Articulata, i.e. prior to animals with true segmentation such as annelids and arthropods. This phylum was established by Mikhail A. Fedonkin in 1985 for such animals as Dickinsonia, Vendia, Cephalonega, Praecambridium[3] and currently many other Proarticulata are described (see list).[4][5]
Due to their simplistic morphology, their affinities and mode of life are subject to debate. They are almost universally considered to be metazoans, and due to possessing a clear central axis have been suggested to be stem-bilaterians. In the traditional interpretation, the Proarticulatan body is divided into transverse articulation (division) into isomers as distinct from the transverse articulation segments in annelids and arthropods, as their individual isomers occupy only half the width of their bodies, and are organized in an alternating pattern along the longitudinal axis of their bodies.[5] In other words, one side is not the direct mirror image of its opposite (chirality). Opposite isomers of left and right side are located with displacement of half of their width. This phenomenon is described as the symmetry of gliding reflection.[6][7] Some recent research suggests that some proarticulatans like Dickinsonia have genuine segments, and the isomerism is superficial and due to taphonomic distortion.[8] However, other researchers dispute this.[9][10] Displacement of left-right axis is known in bilaterians, notably lancelets.[11][12]
^Maslov AV, Podkovyrov VN, Grazhdankin DV, Kolesnikov AV (2018). "Upper Vendian in the east, northeast and north of East European Platform: Depositional processes and biotic evolution". Litosfera. 18 (4): 520–542. doi:10.24930/1681-9004-2018-18-4-520-542.
^Kolesnikov AV, Liu AG, Danelian T, Grazhdankin DV (2018). "A reassessment of the problematic Ediacaran genus Orbisiana Sokolov 1976". Precambrian Research. 316: 197–205. Bibcode:2018PreR..316..197K. doi:10.1016/j.precamres.2018.08.011. S2CID 134213721.
^Fedonkin MA (1985). "Systematic Description of Vendian Metazoa". In Sokolov BS, Iwanowski AB (eds.). Vendian System: Historical–Geological and Paleontological Foundation. Vol. 1: Paleontology. Moscow: Nauka. pp. 70–106.
^Fedonkin MA (31 March 2003). "The origin of the Metazoa in the light of the Proterozoic fossil record" (PDF). Paleontological Research. 7 (1): 9–41. doi:10.2517/prpsj.7.9. S2CID 55178329.
^ abIvantsov AY, Fedonkin MA, Nagovitsyn AL, Zakrevskaya ZA (2019). "Cephalonega, a new generic name, and the system of Vendian Proarticulata". Paleontological Journal. 53 (5): 447–454. doi:10.1134/S0031030119050046. S2CID 203853224.
^Cite error: The named reference Ivantsov2001 was invoked but never defined (see the help page).
^Cite error: The named reference Ivantsov1999 was invoked but never defined (see the help page).
^Dunn FS, Liu AG, Donoghue PC (May 2018). "Ediacaran developmental biology". Biological Reviews of the Cambridge Philosophical Society. 93 (2): 914–932. doi:10.1111/brv.12379. PMC 5947158. PMID 29105292.
^Ivantsov AY, Zakrevskaya MA, Nagovitsyn AL (June 2019). "Morphology of integuments of the Precambrian animals, Proarticulata". Invertebrate Zoology. 16 (1): 19–26. doi:10.15298/invertzool.16.1.03.
^Ivantsov Y, Fedonkin MA, Nagovitsyn AL, Zakrevskaya MA (September 2019). "Cephalonega, A New Generic Name, and the System of Vendian Proarticulata". Paleontological Journal. 53 (5): 447–454. doi:10.1134/s0031030119050046. S2CID 203853224.
^Blum M, Feistel K, Thumberger T, Schweickert A (April 2014). "The evolution and conservation of left-right patterning mechanisms". Development. 141 (8): 1603–13. doi:10.1242/dev.100560. PMID 24715452.
^Soukup V (2017). "Left-right asymmetry specification in amphioxus: review and prospects". The International Journal of Developmental Biology. 61 (10–11–12): 611–620. doi:10.1387/ijdb.170251vs. PMID 29319110.
Proarticulata is a proposed phylum of extinct, near-bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits...
beehive. Dickinsonia is classified as part of the group Proarticulata or Dickinsoniomorpha. Proarticulata includes a number of morphologically similar organisms...
by now-extinct, relatively simple soft-bodied animal phyla such as Proarticulata (bilaterians with simple articulation, e.g. Dickinsonia and Spriggina)...
of 25 cm (9.8 in). It is classified within the extinct animal phylum Proarticulata. The generic name Yorgia comes from the Yorga river on the Zimnii Bereg...
However, it is considered that the movement would have appeared in Proarticulata and would have been slow and sliding; presumably, mobile representatives...
Xenacoelomorpha, Nephrozoa Nephrozoa: Protostomes, Deuterostomes Phylum Proarticulata † Disputed if this is in or out of Bilateria and Phylum Xenacoelomorpha...
identified to be a bilaterian triploblastic animal in the Ediacaran phylum Proarticulata, known from the Winter Coast, White Sea, Russia. It was first discovered...
trilobites and arthropods. In 1985 Mikhail Fedonkin erected Phylum Proarticulata, in which he placed: Cephalonega, Dickinsonia, Palaeoplatoda, Vendia...
Priapulida Little Priapus Penis worms Penis-shaped worms approx. 20 Proarticulata Before articulates Proarticulates An extinct group of mattress-like...
most often interpreted as an early arthropod, annelid, or a member of Proarticulata, but as with all Ediacarian fauna its phylogeny remains uncertain. Initially...
Epibaion is a trace fossil imprint of the Ediacaran animals of the phylum Proarticulata, which became extinct in the Precambrian. Imprints often occurring in...
maint: multiple names: authors list (link) Ivantsov, A. Yu (2004). "New Proarticulata from the Vendian of the Arkhangel'sk Region" (PDF). Paleontological...
Vendiamorpha is a class of extinct animals within the Ediacaran phylum Proarticulata. The typical vendiamorph had an oval-shaped or round-shaped body divided...
and we can not prove either an opposite or an alternate (as in the Proarticulata) arrangement of the half-segments. A.Yu. Ivantsov (2017). "The most...
The largest prehistoric animals include both vertebrate and invertebrate species. Many of them are described below, along with their typical range of size...
with bizarre trace fossils. It is placed within the extinct phylum Proarticulata, and contains the defined genera Dickinsonia and probably Windermeria...
extinct class of primitive segmented marine organisms within the Phylum Proarticulata from the Ediacaran period. They possessed bilateral symmetry and were...
Dickinsonia and other Proarticulates. Archaeaspinus belongs to the phylum Proarticulata. Within that, its class is Cephalozoa and family Yorgiidae. Until 2004...
Class Vendiamorpha of the extinct Ediacaran (Vendian) animal Phylum Proarticulata. The Charnwood Forest form, Pseudovendia charnwoodensis has been synonymized...
trilobite-like arthropod, though the majority of experts now place it within the Proarticulata as a close relative of the much larger Yorgia. It is from the Late Ediacaran...
taxonomy.nl. Retrieved 15 December 2018. Ivantsov, A. Yu. (2004). "New Proarticulata from the Vendian of the Arkhangel'sk Region". Paleontological Journal...
make osmotic feeding viable. Rangeomorpha, a probable sister clade Proarticulata, sharing similar 'glide symmetry' Ediacara biota, for an overview of...
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