Proarticulata is a proposed phylum of extinct, 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]
Proarticulata
Temporal range: Late Ediacaran, between 567–550 Ma
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]
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).[6][13][14][15]
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).[6][13][15][16] Some cephalozoans from the familyYorgiidae demonstrate pronounced asymmetry of 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.[6][7][15]
Artist's reconstruction of Lossinia feeding on surface algae.
In Cephalonega stepanovi and Tamga hamulifera the zone containing the isomers is encircled by a peripheral, undivided zone.[16] 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."[16]
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.[13][16][18]
^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.
^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.
^ abcdefg Ivantsov, A.Yu. (2001). "Vendia and other precambrian "Arthropods"". Paleontological Journal. 35 (4): 335–343.
^ abc Ivantsov, A.Yu. (1999). "A new Dickinsoniid from the upper Vendian of the White Sea Winter Coast (Russia, Arkhangelsk region)". Paleontological Journal. 33 (3): 233–241.
^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. PMC5947158. 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.
^ abcdef Ivantsov, A.Yu. (2004). (PDF). Paleontological Journal. 38 (3): 247–253. Archived from the original (PDF) on 2007-09-27.
^ Ivantsov, A.Yu.; Malakhovskaya, Y.E.; Serezhnikova, E.A. (2004). (PDF). Paleontological Journal. 38 (1): 1–9. Archived from the original (PDF) on 2007-07-04.
^ abc Ivantsov, A.Yu. (2004). Vendian animals in the phylum Proarticulata(PDF). The Rise and Fall of the Vendian Biota. Prato, Italy. p. 52. IGSP Project 493.
^ ab Ivantsov, A.Yu.; Malakhovskaya, Y.E. (2002). (PDF). Doklady Earth Sciences. 385 (6): 618–622. Archived from the original (PDF) on 2007-07-04.
^Ivantsov AY (December 2010). "Paleontological evidence for the supposed precambrian occurrence of mollusks". Paleontological Journal. 40 (12): 1552–1559. doi:10.1134/S0031030110120105. S2CID 86523806.
^Fedonkin MA (2002). "Andiva ivantsovi gen. et sp. n. and related carapace‐bearing Ediacaran fossils from the Vendian of the Winter Coast, White Sea, Russia". Italian Journal of Zoology. 69 (2): 175–181. doi:10.1080/11250000209356456. S2CID 85352552.
^Ivantsov AY, Fedonkin MA, Nagovitsyn AL, Zakrevskaya MA (2019). "Cephalonega, a new generic name, and the system of Vendian Proarticulata". Paleontological Journal. 53 (5): 447–454. doi:10.1134/S0031030119050046. S2CID 203853224.
^ abKeller BM, Fedonkin MA (1976). (PDF). Izvestiya Akademii Nauk SSR. Seriya Geologicheskaya (in Russian). 3: 38–44. Archived from the original (PDF) on 2007-09-27.
^ Dzik, J.; Martyshyn, A. (2015). "Taphonomy of the Ediacaran Podolimirus and associated dipleurozoans from the Vendian of Ukraine". Precambrian Research. 269: 139–146. doi:10.1016/j.precamres.2015.08.015.
^Narbonne GM (May 1994). "New Ediacaran fossils from the Mackenzie Mountains, Northwestern Canada". Journal of Paleontology. 63 (3): 411–416. doi:10.1017/S0022336000025816. JSTOR 1306192.
^Ivantsov AY (May 2011). "Feeding traces of Proarticulata — the Vendian metazoa". Paleontological Journal. 45 (3): 237–248. doi:10.1134/S0031030111030063. S2CID 128741869.
External links
Advent of Complex Life
January 31, 2023
proarticulata, proposed, phylum, extinct, bilaterally, symmetrical, animals, known, from, fossils, found, ediacaran, vendian, marine, deposits, dates, approximately, million, years, name, comes, from, greek, προ, before, articulata, prior, animals, with, true,. Proarticulata is a proposed phylum of extinct 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 pro 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 ProarticulataTemporal range Late Ediacaran between 567 550 Ma PreꞒ Ꞓ O S D C P T J K Pg NFossil of Dickinsonia costataFossil of SprigginaScientific classificationKingdom AnimaliaSubkingdom EumetazoaClade ParaHoxozoaClade BilateriaPhylum ProarticulataFedonkin 1985Class Family Vendiamorpha Fedonkin 1985 Vendiidae Ivantsov Dipleurozoa Harrington amp Moore 1955 Dickinsoniidae Harrington amp Moore 1955 Cephalozoa Ivantsov 2004 Sprigginidae Glaessner 1958 Yorgiidae Ivantsov 2001For more taxa see textDue 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 Contents 1 Morphology 1 1 Vendiamorpha 1 2 Cephalozoa 1 3 Dipleurozoa 2 List of Proarticulata 2 1 Body fossils 2 2 Trace fossils 3 See also 4 References 5 External linksMorphology Edit Examples of the classes Proarticulata including reconstructions of Vendia sokolovi Dickinsonia costata and Yorgia waggoneri Vendiamorpha Edit Main article 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 6 13 14 15 Cephalozoa Edit Main article 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 6 13 15 16 Some cephalozoans from the family Yorgiidae demonstrate pronounced asymmetry of 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 6 7 15 Artist s reconstruction of Cephalonega stepanovi 17 Artist s reconstruction of Lossinia feeding on surface algae In Cephalonega stepanovi and Tamga hamulifera the zone containing the isomers is encircled by a peripheral undivided zone 16 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 16 Dipleurozoa Edit Main article 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 13 16 18 List of Proarticulata Edit Andiva ivantsovi Dickinsonia costata Spriggina floundersi Ovatoscutum concentricum Yorgia waggoneri Tamga hamulifera Body fossils Edit Armillifera Fedonkin 1980 19 A parva Fedonkin 1980Andiva Fedonkin 2002 20 A ivantsovi Fedonkin 2002Archaeaspinus Ivantsov 2007 6 Archaeaspis Ivantsov 2001 16 A fedonkini Ivantsov 2001Cephalonega Ivantsov et al 2019 21 C stepanovi Fedonkin 1976 16 22 Chondroplon Wade 1971 possible Dickinsonia C bilobatum Wade 1971Cyanorus Ivantsov 2004 13 C singularis Ivantsov 2004Dickinsonia Sprigg 1947D costata Sprigg 1947 D lissa Wade 1972 D menneri Keller 1976 16 Vendomia menneri Keller 1976 22 D tenuis Glaessner amp Wade 1966Ivovicia Ivantsov 2007 16 I rugulosa Ivantsov 2007Karakhtia Ivantsov 2004K nessovi Ivantsov 2004Lossinia Ivantsov 2007 16 L lissetskii Ivantsov 2007Marywadea Glaessner 1976M ovata Glaessner amp Wade 1966Ovatoscutum Glaessner amp Wade 1966O concentricum Glaessner amp Wade 1966Paravendia Ivantsov 2004 6 13 P janae Ivantsov 2001 Vendia janae Ivantsov 2001 Podolimirus Fedonkin 1983 Valdainia Fedonkin 1983 23 P mirus Fedonkin 1983 Valdainia plumosa Fedonkin 1983 Praecambridium Glaessner amp Wade 1966P siggilum Glaessner amp Wade 1966Spriggina Glaessner 1958S floundersi Glaessner 1958Tamga Ivantsov 2007 16 T hamulifera Ivantsov 2007Vendia Keller 1969 6 13 V sokolovi Keller 1969 V rachiata Ivantsov 2004 Windermeria Narbonne 1994W aitkeni Narbonne 1994 24 Yorgia Ivantsov 1999 7 Y waggoneri Ivantsov 1999Trace fossils Edit Epibaion Ivantsov 2002 18 25 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 costataPhyllozoon Jenkins amp Gehling 1978P hanseni Jenkins amp Gehling 1978See also EditArticulata List of Ediacaran generaReferences Edit 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 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 a b Ivantsov 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 a b c d e f g Ivantsov A Yu 2001 Vendia and other precambrian Arthropods Paleontological Journal 35 4 335 343 a b c Ivantsov A Yu 1999 A new Dickinsoniid from the upper Vendian of the White Sea Winter Coast Russia Arkhangelsk region Paleontological Journal 33 3 233 241 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 a b c d e f Ivantsov A Yu 2004 New Proarticulata from the Vendian of the Arkhangel sk Region PDF Paleontological Journal 38 3 247 253 Archived from the original PDF on 2007 09 27 Ivantsov A Yu Malakhovskaya Y E Serezhnikova E A 2004 Some problematic fossils from the Vendian of the south eastern White Sea region PDF Paleontological Journal 38 1 1 9 Archived from the original PDF on 2007 07 04 a b c Ivantsov A Yu 2004 Vendian animals in the phylumProarticulata PDF The Rise and Fall of the Vendian Biota Prato Italy p 52 IGSP Project 493 a b c d e f g h i j Ivantsov A Yu April 2007 Small Vendian transversely articulated fossils Paleontological Journal 41 2 113 122 doi 10 1134 S0031030107020013 S2CID 86636748 illustration c Stanton F Fink a b Ivantsov A Yu Malakhovskaya Y E 2002 Giant traces of Vendian animals PDF Doklady Earth Sciences 385 6 618 622 Archived from the original PDF on 2007 07 04 Ivantsov AY December 2010 Paleontological evidence for the supposed precambrian occurrence of mollusks Paleontological Journal 40 12 1552 1559 doi 10 1134 S0031030110120105 S2CID 86523806 Fedonkin MA 2002 Andiva ivantsovi gen et sp n and related carapace bearing Ediacaran fossils from the Vendian of the Winter Coast White Sea Russia Italian Journal of Zoology 69 2 175 181 doi 10 1080 11250000209356456 S2CID 85352552 Ivantsov AY Fedonkin MA Nagovitsyn AL Zakrevskaya MA 2019 Cephalonega a new generic name and the system of Vendian Proarticulata Paleontological Journal 53 5 447 454 doi 10 1134 S0031030119050046 S2CID 203853224 a b Keller BM Fedonkin MA 1976 New Records of Fossils in the Valdaian Group of the Precambrian on the Syuz ma River PDF Izvestiya Akademii Nauk SSR Seriya Geologicheskaya in Russian 3 38 44 Archived from the original PDF on 2007 09 27 Dzik J Martyshyn A 2015 Taphonomy of the Ediacaran Podolimirus and associated dipleurozoans from the Vendian of Ukraine Precambrian Research 269 139 146 doi 10 1016 j precamres 2015 08 015 Narbonne GM May 1994 New Ediacaran fossils from the Mackenzie Mountains Northwestern Canada Journal of Paleontology 63 3 411 416 doi 10 1017 S0022336000025816 JSTOR 1306192 Ivantsov AY May 2011 Feeding traces of Proarticulata the Vendian metazoa Paleontological Journal 45 3 237 248 doi 10 1134 S0031030111030063 S2CID 128741869 External links EditDatabase of Ediacaran Biota Advent of Complex Life Retrieved from https en wikipedia org w index php title Proarticulata amp oldid 1136093275, wikipedia, wiki, book, books, library,
