# Orbisiana > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Orbisiana > Markdown URL: https://mediated.wiki/source/Orbisiana.md > Source: https://en.wikipedia.org/wiki/Orbisiana > Source revision: 1344612260 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Enigmatic agglutinating organism from the Ediacaran}} {{Automatic taxobox | fossil_range = late [Ediacaran](/source/Ediacaran)
~{{long fossil range|575|538|earliest=580}}{{period fossil range|Neoproterozoic|575|538|earliest=580}} | image = Orbisiana spumea and grazing trips left by Kimberella.png | image_caption = A fossil of ''Orbisiana spumea'' | taxon = Orbisiana | authority = Sokolov, 1976 | type_species = {{extinct}}'''''Orbisiana simplex''''' | type_species_authority = Sokolov, 1976 | subdivision = * ''O. simplex'' Sokolov, 1976 * ''O. spumea'' Kolesnikov et al., 2022 * ''O. intorta'' Kolesnikov et al., 2022 | synonyms = * ''Neonereites'' Sokolov & Fedonkin, 1984 ** ''N. multiserialis'' Ivantsov et al., 2018 }} '''''Orbisiana''''' is an enigmatic [extinct](/source/extinct) organism from the [Ediacaran](/source/Ediacaran), and is made up of agglutinated spherical or hemispherical chambers. Recent studies have suggested and supported an affinity with ''[Palaeopascichnus](/source/Palaeopascichnus)'', and other similar organisms from the Ediacaran. == Discovery == The [holotype](/source/holotype) fossil of ''Orbisiana'' was found in the Soligalich 7 [core](/source/Core_sample), which was collected from the Lower Member of the [Gavrilov Yam Formation](/source/Gavrilov_Yam_Formation) in [Ladoga](/source/Novaya_Ladoga), [Western Russia](/source/Western_Russia) sometime during the 1960s, and was formally described and named in 1976.{{Cite journal |last1= Sokolov |first1= B. S. |title= Organicheskii mir Zemli na puti k fanerozoiskoi differentsiatsii|trans-title= The Earth's organic world on the path toward Phanerozoic differentiation |journal= Vestnik Akademii Nauk SSR |volume= 1 |pages= 126–143 |year= 1976}}{{cite journal |last1=Kolesnikov |first1=Anton V. |last2=Liu |first2=Alexander G. |last3=Danelian |first3=Taniel |last4=Grazhdankin |first4=Dmitriy V. |title=A reassessment of the problematic Ediacaran genus Orbisiana Sokolov 1976 |journal=Precambrian Research |date=October 2018 |volume=316 |pages=197–205 |doi=10.1016/j.precamres.2018.08.011}} == Description == ''Orbisiana'' is an agglutinating organism, consisting of spherical to hemispherical chambers arranged in long strings or clustered aggregates with an irregular outline. The chambers themselves are commonly found getting up to {{cvt|0.2-2.6|mm|2}} in diameter, and in all known specimens, the walls of the chambers are composed of a [carbonaceous](/source/carbonaceous) material, and are in-filled with sediment that is similar, or the same, as the matrix rock outside the fossils.{{Cite journal |last1= Jensen |first1= Sören |date= 2003 |title= The Proterozoic and Earliest Cambrian Trace Fossil Record; Patterns, Problems and Perspectives |journal= Integrative and Comparative Biology |volume= 43 |issue= 1 |pages= 219–228 |doi= 10.1093/icb/43.1.219 |pmid= 21680425 |issn= 1540-7063 |doi-access= free}} The overall body can be composed of 4 to 150 uniform chambers reaching up to {{cvt|70|mm|1}} in length, with some specimens showing dichotomous branching, although this is noted to be uncommon.{{Cite journal |last1= Wan |first1= Bin |last2= Xiao |first2= Shuhai |last3= Yuan |first3= Xunlai |last4= Chen |first4= Zhe |last5= Pang |first5= Ke |last6= Tang |first6= Qing |last7= Guan |first7= Chengguo |last8= Maisano |first8= Jessica A. |title= Orbisiana linearis from the early Ediacaran Lantian Formation of South China and its taphonomic and ecological implications |journal= Precambrian Research |volume= 255 |pages= 266–275 |doi= 10.1016/j.precamres.2014.09.028 |year= 2014 |bibcode= 2014PreR..255..266W}} == Palaeoecology == Specimens of ''Orbisiana'' are commonly preserved as two to three-dimensional compressions in the rock, with the walls being either carbonaceous or pyritic in composition. From this, with 3D scanning of three-dimensional specimens, it was found that the chambers are straight cylinders, which are open at either end. This suggested that the walls of ''Orbisiana'' are partly rigid, as well as possibly being partially embedded into the sediment, meaning that ''Orbisiana'' was an benthic organism that lived either on top of or partially buried in sediments. A prior study also noted that ''Orbisiana'' likely favoured calm and well aerated shallow marine waters.{{Cite journal|last1=Fedonkin|first1=M. A.|last2=Simonetta|first2=A.|last3=Ivantsov|first3=A. Y.|title=New data on Kimberella, the Vendian mollusc-like organism (White Sea region, Russia): palaeoecological and evolutionary implications|journal=Geological Society, London, Special Publications|volume=286|issue=1|pages=157–179|doi=10.1144/sp286.12|year=2007|bibcode=2007GSLSP.286..157F|s2cid=331187}} A later study done in 2018 found that the chambers of ''Orbisiana'' are not open ended, and may instead be a result of the local taphonomy, although is still regarded as a benthic organism. The study suggested that the walls may have been made up of clay grains in life, which were "glued" together to form said chambers, and as such would have easily collapsed during burial. == Affinities == Since it was discovered, ''Orbisiana'' has been suggested to be a number of things. When originally described in 1976, it was interpreted to be a aggregate of large cells, although in 1984 two studies had been published, with one interpreting ''Orbisiana'' to be fecal pellets,{{Cite journal |last1= Chistyakov |first1= B.G. |last2= Kalmykova |first2= N.A. |last3= Nesov |first3= L.A. |last4= Suslov |first4= G.A. |title= O nalichii vendskikh otlozhenij v srednem techenii r Onegi i vozmozhnom syshchestvovanii obolochnikov (Tunicata: Chordata) v dokembrii |trans-title= On the Presence of the Vendian Deposits in the Mid-stream of Onega River and on the Possible Existence of Tunicates (Tunicata: Chordata) in the Precambrian |journal= Vestnik of the Leningrad State University |volume= 6 |pages= 11–19 |year= 1984}} and the other suggesting it to be an [acritarch](/source/acritarch).{{Cite journal |last1= Sokolov |first1= Boris S. |last2= Fedonkin |first2= Mikhail A. |title= The Vendian as the Terminal System of the Precambrian |journal= Episodes |date= 1 March 1984 |volume= 7 |issue= 1 |pages= 12–19 |doi=10.18814/epiiugs/1984/v7i1/004|doi-access= free }} Later, in 1992 and 1994, it was further reinterpreted as an algae.{{Cite journal |last1= Yan |first1= Y. |last2= Jiang |first2= C. |last3= Zhang |first3= S. |last4= Du |first4= S. |last5= Bi |first5= Y. |title= Research of the Sinian System in the region of western Zhejiang, northern Jiangxi, and southern Anhui provinces |journal= Bulletin of the Nanjing Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences |volume= 12 |pages= 1–105}}{{Cite journal |last1= Chen |first1= M. |last2= Lu |first2= G. |last3= Xiao |first3= Z. |title= Preliminary study on the algal macrofossils – Lantian Flora from the Lantian Formation of Upper Sinian in southern Anhui |journal= Bulletin Institute of Geology, Academia Sinica |volume= 7 |pages= 252–267}} But, in 2014 when the [Lantian](/source/Lantian_Formation) forms were properly described, it was noted that their general morphology discounts any of these prior interpretations, and is instead regarded as problematica until further evidence is found, although it was also noted that ''Orbisiana'' bears morphological similarities with other agglutinating organisms, such as ''Palaeopascichnus'', and was also placed into the proposed group [Palaeopascichnida](/source/Palaeopascichnida) in the same year.{{Cite journal |last1= Grazhdankin |first1= Dmitriy |title= Patterns of Evolution of the Ediacaran Soft-Bodied Biota |journal= Journal of Paleontology |date= March 2014 |volume= 88 |issue= 2 |pages= 269–283 |doi= 10.1666/13-072}} These probable affinities with the palaeopascichnids has been further supported after the rediscovery of the previously lost holotype specimen, although the Lantian forms == Taxonomy and Distribution == ''Orbisiana'' contains three valid species which are restricted to [Asia](/source/Asia), and one now synonmyised species, which are as follows: *† ''O. simplex'' Sokolov, 1976 - Known from across the [White Sea](/source/White_Sea) area in [Russia](/source/Russia),{{Cite journal |last1= Grazhdankin |first1= D.Z. |last2= Maslov |first2= A.V. |last3= Krupenin |first3= M.T. |last4= Ronkin |first4= Y.L. |title= Osadochnye Sistemy Sylvitskoi Serii: Verkhnii Vend Srednego Urala |trans-title= Depositional systems of the Sylvitsa Group: Upper Vendian of Central Urals |journal= Ekaterinburg |pages= 280|year= 2010}}{{Cite journal |last1= Grazhdankin |first1= D.Z. |title= Upper Vendian Chronostratigraphy, Trofimuk Institute of Petroleum Geology and Geophysics |journal= Novosibirsk |pages= 34|year= 2012}} as well as [Eastern Siberia](/source/Eastern_Siberia).{{cite journal |last1=Ivantsov |first1=A. Yu. |title=Finds of Ediacaran-type fossils in Vendian deposits of the Yudoma Group, Eastern Siberia |journal=Doklady Earth Sciences |date=February 2017 |volume=472 |issue=2 |pages=143–146 |doi=10.1134/S1028334X17020131}} *† ''O. spumea'' Kolesnikov et al., 2022 - Known from the [Ustʹ Pinega Formation](/source/Ust%CA%B9_Pinega_Formation), Russia.{{cite journal |last1=Kolesnikov |first1=Anton |last2=Desiatkin |first2=Vladislav |title=Taxonomy and palaeoenvironmental distribution of palaeopascichnids |journal=Geological Magazine |date=July 2022 |volume=159 |issue=7 |pages=1175–1191 |doi=10.1017/S0016756822000437}} *† ''O. intorta'' Kolesnikov et al., 2022 - Known from across the [White Sea](/source/White_Sea) area in [Russia](/source/Russia). *† ''O. linearis'' Chen, 1994 - Known from the middle Ediacaran Lantian Formation, [Anhui Province](/source/Anhui_Province), [South China](/source/South_China). Later studies moved the species into ''Palaeopascichnus''. Specimens which are unattributed to either species have also been found in the [Dongpo Formation](/source/Dongpo_Formation) in [Central China](/source/Central_China),{{cite journal |last1=Wang |first1=Xin |last2=Zhang |first2=Xingliang |last3=Dai |first3=Tao |last4=Liu |first4=Wei |last5=Zhang |first5=Yuan |last6=Li |first6=Luoyang |title=New occurrence of a postglacial Ediacaran macrofossil assemblage from North China and its evolutionary implication |journal=Precambrian Research |date=March 2026 |volume=434 |article-number=107992 |doi=10.1016/j.precamres.2025.107992}}, as well as probable occurrences in the [Rocky Harbour Formation](/source/Rocky_Harbour_Formation) in [Canada](/source/Canada).{{cite journal |last1=Liu |first1=Alexander G. |last2=Tindal |first2=Benjamin H. |title=Ediacaran macrofossils prior to the ~580 Ma Gaskiers glaciation in Newfoundland, Canada |journal=Lethaia |date=April 2021 |volume=54 |issue=2 |pages=260–270 |doi=10.1111/let.12401}} == See also == * [Palaeopascichnida](/source/Palaeopascichnida) == References == {{Reflist}} {{Taxonbar|from=Q49000214}} Category:Ediacaran life Category:Ediacaran Asia --- Adapted from the Wikipedia article [Orbisiana](https://en.wikipedia.org/wiki/Orbisiana) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Orbisiana?action=history)). 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