Jump to content

Arumberia: Difference between revisions

Add links
From Wikipedia, the free encyclopedia
Browse history interactively
← Previous edit
Content deleted Content added
VisualWikitext
ce
m v2.05b - Bot T20 CW#61 - Fix errors for CW project (Reference before punctuation)
 
(28 intermediate revisions by 9 users not shown)
Line 1: Line 1:
{{Short description|Trace fossil}}
{{Short description|Trace fossil}}
{{Automatic taxobox
{{Italic title}}
⚫
| fossil_range = Late [[Ediacaran]]
{{Taxobox
⚫
| image = Arumberiabottom.jpg
| color_as = incertae sedis
⚫
| image_caption = Holotype specimen of ''Arumberia banksi'', a convex hyporelief on the base of a sandstone bed from the Ediacaran Arumbera Sandstone near Alice Springs, Australia
⚫
| name = ''Arumberia''
| taxon = Arumberia
⚫
| image = Arumberiabottom.jpg
⚫
| authority = Glaessner et Walter, 1975
⚫
| fossil_range = Late [[Ediacaran]]
⚫
| type_species = ''Arumberia banksi''
⚫
| image_caption = Holotype specimen of Arumberia banksi, a convex hyporelief on the base of a sandstone bed from the Ediacaran Arumbera Sandstone near Alice Springs, Australia
| regnum = ''[[incertae sedis]]''
| genus = '''''Arumberia'''''
⚫
| genus_authority = Glaessner et Walter, 1975
| type_species = ''Arumberia banksi''
| type_species_authority = Glaessner et Walter, 1975
| type_species_authority = Glaessner et Walter, 1975
| subdivision_ranks = Species
| subdivision_ranks = Species
| subdivision = {{species list}}
| subdivision = {{species list}}
* ''A. banksi''
* ''A. banksi''
* ''A. vindhyanensis''
* ''A. vindhyanensis''
Line 22: Line 18:
}}
}}


'''''Arumberia''''' is an enigmatic fossil from the [[Ediacaran]] period<ref name="McIlroy1997">{{Cite journal | last1 = McIlroy | first1 = D. | last2 = Walter | first2 = M. | doi = 10.1080/03115519708619187 | title = A reconsideration of the biogenicity of ''Arumberia banksi'' Glaessner & Walter | journal = Alcheringa: An Australasian Journal of Palaeontology | volume = 21 | pages = 79–80 | year = 1997 }}</ref> originally described from the Arumbera Sandstone, [[Northern Territory]], [[Australia]]<ref name="Glaessner1975">{{Cite journal | last1 = Glaessner | first1 = M. F. | last2 = Walter | first2 = M. R. | doi = 10.1080/03115517508619480 | title = New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia | journal = Alcheringa: An Australasian Journal of Palaeontology | volume = 1 | pages = 59–69 | year = 1975 }}</ref> but also found in the Urals,<ref name=Kolesnikov2012>{{cite journal|last=Maslov, A.V.|first=Kolesnikov, A.V.|author2=Grazhdankin, D.V.|title=Arumberia-type structures in the Upper Vendian of the Urals|journal=Doklady Earth Sciences|year=2012|volume=447|issue=1|pages=1233–1239|url=http://cat.inist.fr/?aModele=afficheN&cpsidt=26582870|access-date=27 January 2013|doi=10.1134/S1028334X12110013|bibcode=2012DokES.447.1233K|s2cid=140695807}}</ref> East Siberia,<ref name=GomezPerez2010>{{cite journal|last=Gómez-Pérez M.|first=Bogolepova O.K.|author2=Gubanov A.P. |author3=Howard J.P. |title=Arumberia and other microbial mats from the Neoproterozoic-Cambrian strata of East Siberia.|journal=Geophysical Research Abstracts|volume=12|pages=3143|year=2010|bibcode=2010EGUGA..12.3143B}}</ref> England and Wales,<ref name="Bland1984">{{Cite journal | last1 = Bland | first1 = B. H. | title = ''Arumberia'' Glaessner & Walter, a review of its potential for correlation in the region of the Precambrian–Cambrian boundary | doi = 10.1017/S0016756800030776 | journal = Geological Magazine | volume = 121 | issue = 6 | pages = 625–633| year = 1984 | bibcode = 1984GeoM..121..625B | s2cid = 128492261 }}</ref> Northern France,<ref name="Bland1984"/> the [[Avalon Peninsula]]<ref name="Bland1984"/> and India.<ref name="Pandey2009"/> Several morphologically distinct species are recognized.<ref name=Kolesnikov2012/><ref name=":02">{{cite journal | doi=10.1134/S1028334X12110013 | title=Arumberia-type structures in the Upper Vendian of the Urals | year=2012 | last1=Kolesnikov | first1=A. V. | last2=Grazhdankin | first2=D. V. | last3=Maslov | first3=A. V. | journal=Doklady Earth Sciences | volume=447 | issue=1 | pages=1233–1239 | bibcode=2012DokES.447.1233K | s2cid=140695807 }}</ref><ref name=":1" />
'''''Arumberia''''' is an enigmatic fossil from the [[Ediacaran]] period<ref name="McIlroy1997">{{Cite journal | last1 = McIlroy | first1 = D. | last2 = Walter | first2 = M. | doi = 10.1080/03115519708619187 | title = A reconsideration of the biogenicity of ''Arumberia banksi'' Glaessner & Walter | journal = Alcheringa: An Australasian Journal of Palaeontology | volume = 21 | pages = 79–80 | year = 1997 | issue = 1 | bibcode = 1997Alch...21...79M }}</ref> originally described from the Arumbera Sandstone, [[Northern Territory]], [[Australia]]<ref name="Glaessner1975">{{Cite journal | last1 = Glaessner | first1 = M. F. | last2 = Walter | first2 = M. R. | doi = 10.1080/03115517508619480 | title = New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia | journal = Alcheringa: An Australasian Journal of Palaeontology | volume = 1 | pages = 59–69 | year = 1975 | issue = 1 | bibcode = 1975Alch....1...59G }}</ref> but also found in the Urals,<ref name=Kolesnikov2012>{{cite journal|title=Arumberia-type structures in the Upper Vendian of the Urals|journal=Doklady Earth Sciences|year=2012|volume=447|issue=1|pages=1233–1239|url=http://cat.inist.fr/?aModele=afficheN&cpsidt=26582870|access-date=27 January 2013|doi=10.1134/S1028334X12110013|bibcode=2012DokES.447.1233K|s2cid=140695807 |last1=Kolesnikov |first1=A. V. |last2=Grazhdankin |first2=D. V. |last3=Maslov |first3=A. V. }}</ref> East Siberia,<ref name=GomezPerez2010>{{cite journal |title=Arumberia and other microbial mats from the Neoproterozoic-Cambrian strata of East Siberia.|journal=Geophysical Research Abstracts|volume=12|pages=3143|year=2010|bibcode=2010EGUGA..12.3143B |last1=Bogolepova |first1=O. K. |last2=Gubanov |first2=A. P. |last3=Howard |first3=J. P. |last4=Gómez-Pérez |first4=M. }}</ref> England and Wales,<ref name="Bland1984">{{Cite journal | last1 = Bland | first1 = B. H. | title = ''Arumberia'' Glaessner & Walter, a review of its potential for correlation in the region of the Precambrian–Cambrian boundary | doi = 10.1017/S0016756800030776 | journal = Geological Magazine | volume = 121 | issue = 6 | pages = 625–633| year = 1984 | bibcode = 1984GeoM..121..625B | s2cid = 128492261 }}</ref> Northern France,<ref name="Bland1984"/> the [[Avalon Peninsula]],<ref name="Bland1984"/> India<ref name="Pandey2009"/> and Brazil.<ref>{{Cite journal |last1=Becker-Kerber |first1=Bruno |last2=El Albani |first2=Abderrazak |last3=Konhauser |first3=Kurt |last4=Abd Elmola |first4=Ahmed |last5=Fontaine |first5=Claude |last6=Paim |first6=Paulo S. G. |last7=Mazurier |first7=Arnaud |last8=Prado |first8=Gustavo M. E. M. |last9=Galante |first9=Douglas |last10=Kerber |first10=Pedro B. |last11=da Rosa |first11=Ana L. Z. |last12=Fairchild |first12=Thomas R. |last13=Meunier |first13=Alain |last14=Pacheco |first14=Mírian L. A. F. |date=2021-03-03 |title=The role of volcanic-derived clays in the preservation of Ediacaran biota from the Itajaí Basin (ca. 563 Ma, Brazil) |journal=Scientific Reports |language=en |volume=11 |issue=1 |pages=5013 |doi=10.1038/s41598-021-84433-0 |pmid=33658558 |issn=2045-2322|pmc=7930025 }}</ref> Several morphologically distinct species are recognized.<ref name=Kolesnikov2012/><ref name=":1" />


== Description ==
==Description==
Initially discovered by Glaessner and Walter (1975), ''Arumberia'' was described as a problematic cupped-body fossil of an Ediacaran soft-bodied organism characterized by hollow compressible ribbed bodies composed of flexible tissue. Brasier (1979) deemed it a pseudofossil arising from turbid water flow in shallow marine or deltaic environments, due in part to physical and morphological similarities to flume-induced structures previously observed by Dzulynski and Walton (1965). ''Arumberia'' appears as a poorly-delimited series of fine parallel grooves arising from a single region or point. ''Arumberia banksii'' consists of an array of straight to gently curved parallel to subparallel ridges (rugae) about 1 – 3&nbsp;mm wide and separated by flat to gently concave furrows of 1 – 7&nbsp;mm in width. Relief from ridge top to furrow bottom is less than 1&nbsp;mm. Ridge ranges in length from 1.5&nbsp;cm to 14.5&nbsp;cm. Generally the ridges are parallel, but they also bifurcate. Ridges are developed on plane and rippled surfaces.<ref name="Pandey2009">{{cite journal |last1=Kumar |first1=S. |last2=Pandey |first2=S. K. |date=December 2009 |title=Note on the occurrence of Arumberia Banksi and associated fossils from the Jodhpur Sandstone, Marwar Supergroup, western Rajasthan |url=http://palaeontologicalsociety.in/vol54_2/v6.pdf |journal=Journal of the Paleontological Society of India |volume=54 |issue=2 |pages=171–178}}</ref>
Initially discovered by Glaessner and Walter (1975), ''Arumberia'' was described as a problematic cupped-body fossil of an Ediacaran soft-bodied organism characterized by hollow compressible ribbed bodies composed of flexible tissue. Brasier (1979) deemed it a [[pseudofossil]] arising from turbid water flow in shallow marine or deltaic environments, due in part to physical and morphological similarities to flume-induced structures previously observed by Dzulynski and Walton (1965). ''Arumberia'' appears as a poorly-delimited series of fine parallel grooves arising from a single region or point. ''Arumberia banksii'' consists of an array of straight to gently curved parallel to subparallel ridges (rugae) about 1 – 3&nbsp;mm wide and separated by flat to gently concave furrows of 1 – 7&nbsp;mm in width. Relief from ridge top to furrow bottom is less than 1&nbsp;mm. Ridge ranges in length from 1.5&nbsp;cm to 14.5&nbsp;cm. Generally the ridges are parallel, but they also bifurcate. Ridges are developed on plane and rippled surfaces.<ref name="Pandey2009">{{cite journal |last1=Kumar |first1=S. |last2=Pandey |first2=S. K. |date=December 2009 |title=Note on the occurrence of Arumberia Banksi and associated fossils from the Jodhpur Sandstone, Marwar Supergroup, western Rajasthan |url=http://palaeontologicalsociety.in/vol54_2/v6.pdf |journal=Journal of the Paleontological Society of India |volume=54 |issue=2 |pages=171–178}}</ref>


== List of Species ==
==List of species==
There are four species of ''Arumberia that'' have been formally recognized. ''Arumberia banksi'' has thin siliciclastic biolaminites known as rugose structures<ref name=":02"/> including those with subparallel or fanning-out series of rugae (''Arumberia banksi'' s.str.) and sub-parallel series of branching rugae (''Arumberia vindhyanensis'').<ref name=":02"/> The ''Arumberia multykensis'' variety is found in greenish gray siltstones as series of near-parallel ridges with positive hyporelief up to 1&nbsp;mm wide and 0.5&nbsp;mm high, with 10&nbsp;mm spacing between the ridges<ref name=":02" /> while ''A. usavaensis'' occurs as a series of near parallel ridges on the wavy surfaces on linguoid ripple marks which stretch along the paleoflow direction and flatten out as microterraces on the leeward side of the ripples<ref name=":02"/>. ''Arumberia usavensis'' is found on both upper and lower surfaces of sandstone beds as well as inside sandstones and siltstones<ref name=":02"/>. ''Arumberia beckeri'' and ''Arumberia ollii'' are morphologically distinct from ''A. banksi''<ref name=":02"/> and are filamentous and ribbon-shaped compressed macrofossils which host authigenic clay minerals and are most likely unrelated to ''Arumberia''.<ref name=":1">{{cite journal | doi=10.1051/bsgf/2017006 | title=Arumberiamorph structure in modern microbial mats: Implications for Ediacaran palaeobiology | year=2017 | last1=Kolesnikov | first1=Anton V. | last2=Danelian | first2=Taniel | last3=Gommeaux | first3=Maxime | last4=Maslov | first4=Andrey V. | last5=Grazhdankin | first5=Dmitriy V. | journal=Bulletin de la Société Géologique de France | volume=188 | issue=1–2 | page=5 }}</ref>
There are four species of ''Arumberia that'' have been formally recognized. ''Arumberia banksi'' has thin siliciclastic biolaminites known as rugose structures<ref name=Kolesnikov2012/> including those with subparallel or fanning-out series of rugae (''Arumberia banksi'' s.str.) and sub-parallel series of branching rugae (''Arumberia vindhyanensis'').<ref name=Kolesnikov2012/> The ''Arumberia multykensis'' variety is found in greenish gray siltstones as series of near-parallel ridges with positive hyporelief up to 1&nbsp;mm wide and 0.5&nbsp;mm high, with 10&nbsp;mm spacing between the ridges<ref name=Kolesnikov2012 /> while ''A. usavaensis'' occurs as a series of near parallel ridges on the wavy surfaces on linguoid ripple marks which stretch along the paleoflow direction and flatten out as microterraces on the leeward side of the ripples.<ref name=Kolesnikov2012/> ''Arumberia usavensis'' is found on both upper and lower surfaces of sandstone beds as well as inside sandstones and siltstones.<ref name=Kolesnikov2012/> ''Arumberia beckeri'' and ''Arumberia ollii'' are morphologically distinct from ''A. banksi''<ref name=Kolesnikov2012/> and are filamentous and ribbon-shaped compressed macrofossils which host authigenic clay minerals and are most likely unrelated to ''Arumberia''.<ref name=":1">{{cite journal | doi=10.1051/bsgf/2017006 | title=Arumberiamorph structure in modern microbial mats: Implications for Ediacaran palaeobiology | year=2017 | last1=Kolesnikov | first1=A. V. | last2=Danelian | first2=T. | last3=Gommeaux | first3=M. | last4=Maslov | first4=A. V. | last5=Grazhdankin | first5=D. V. | journal=Bulletin de la Société Géologique de France | volume=188 | issue=1–2 | page=5 }}</ref>


{{Multiple image
{{Multiple image
Line 49: Line 45:
}}
}}


== Locations ==
==Locations==
''Arumberia'' was first described in [[Neoproterozoic]] red sandstones of the lower ''Arumbera'' sandstone formation of the [[Amadeus Basin]] in Northern Territory, Australia.<ref name="Glaessner1975" /> It has since been found in Argentina, Newfoundland, England, Wales, northeastern Europe, the eastern Sayan Mountains in Russia, Central India, and Rajasthan.<ref name="Bland1984" /><ref name="Pandey2009" /><ref name=":02"/><ref name=":1" /><ref name=":3" /><ref name=":2">{{cite journal | doi=10.1016/j.earscirev.2016.01.005 | title=Resolving MISS conceptions and misconceptions: A geological approach to sedimentary surface textures generated by microbial and abiotic processes | year=2016 | last1=Davies | first1=Neil S. | last2=Liu | first2=Alexander G. | last3=Gibling | first3=Martin R. | last4=Miller | first4=Randall F. | journal=Earth-Science Reviews | volume=154 | pages=210–246 | s2cid=56345018 }}</ref> In addition, ''Arumberia'' has been reported from lower [[Paleozoic|Palaeozoic]] strata in Brittany, France<ref name="Bland1984" /><ref name=":2" /> and from the Upper Ediacaran Cerro Negro Formation in Argentina.<ref name=":3">{{cite journal | doi=10.1038/srep30590 | title=Ediacaran discs from South America: Probable soft-bodied macrofossils unlock the paleogeography of the Clymene Ocean | year=2016 | last1=Arrouy | first1=María Julia | last2=Warren | first2=Lucas V. | last3=Quaglio | first3=Fernanda | last4=Poiré | first4=Daniel G. | last5=Simões | first5=Marcello Guimarães | last6=Rosa | first6=Milena Boselli | last7=Peral | first7=Lucía E. Gómez | journal=Scientific Reports | volume=6 | page=30590 | pmid=27460966 | pmc=4962044 }}</ref>
''Arumberia'' was first described in [[Neoproterozoic]] red sandstones of the lower ''Arumbera'' sandstone formation of the [[Amadeus Basin]] in Northern Territory, Australia.<ref name="Glaessner1975" /> It has since been found in Argentina, Newfoundland, England, Wales, northeastern Europe, the eastern Sayan Mountains in Russia, Central India, and Rajasthan.<ref name="Bland1984" /><ref name="Pandey2009" /><ref name=Kolesnikov2012/><ref name=":1" /><ref name=":3" /><ref name=":2">{{cite journal | doi=10.1016/j.earscirev.2016.01.005 | title=Resolving MISS conceptions and misconceptions: A geological approach to sedimentary surface textures generated by microbial and abiotic processes | year=2016 | last1=Davies | first1=N. S. | last2=Liu | first2=A. G. | last3=Gibling | first3=M. R. | last4=Miller | first4=R. F. | journal=Earth-Science Reviews | volume=154 | pages=210–246 | bibcode=2016ESRv..154..210D | s2cid=56345018 | hdl=1983/bd67cb45-b022-4db0-be3d-b2977d2b81ab | hdl-access=free }}</ref> In addition, ''Arumberia'' has been reported from lower [[Paleozoic|Palaeozoic]] strata in Brittany, France<ref name="Bland1984" /><ref name=":2" /> and from the Upper Ediacaran Cerro Negro Formation in Argentina.<ref name=":3">{{cite journal | doi=10.1038/srep30590 | title=Ediacaran discs from South America: Probable soft-bodied macrofossils unlock the paleogeography of the Clymene Ocean | year=2016 | last1=Arrouy | first1=M. J. | last2=Warren | first2=L. V. | last3=Quaglio | first3=F. | last4=Poiré | first4=D. G. | last5=Simões | first5=M. G. | last6=Rosa | first6=M. B. | last7=Peral | first7=L. E. G. | journal=Scientific Reports | volume=6 | page=30590 | pmid=27460966 | pmc=4962044 | bibcode=2016NatSR...630590A }}</ref>


==Identity==
==Identity==
The identity of ''Arumberia'' is controversial. ''Arumberia'' has been originally interpreted as a 5–20&nbsp;cm high cup-like organism, apparently composed of flexible tissue, attached to the sea bottom by a blunt apex<ref name="Glaessner1975"/> or, later, as a colonial organism made of flexible, thin-walled tubes tightly joined together through their length.<ref name="Bland1984"/> Affinities with ''[[Ernietta]]'', ''[[Conostichus]]'', ''[[Pteridinium]]'', ''Palaeoplatoda'', ''[[Phyllozoon]]'' and ''Bergaueria'' and ''[[Chuaria]]'' have been conjectured.<ref name="Bland1984"/> Spheroidal objects found along with ''Arumberia'' have also been interpreted as "dispersable stage" of ''Arumberia'' itself.<ref name="Bland1984"/> ''Arumberia'' has been interpreted as a microbial mat morphotype developed in response to environmental perturbations in terminal Ediacaran shallow marine basins<ref name=":1" />
The identity of ''Arumberia'' is controversial. ''Arumberia'' has been originally interpreted as a 5–20&nbsp;cm high cup-like organism, apparently composed of flexible tissue, attached to the sea bottom by a blunt apex<ref name="Glaessner1975"/> or, later, as a colonial organism made of flexible, thin-walled tubes tightly joined through their length.<ref name="Bland1984"/> Affinities with ''[[Ernietta]]'', ''[[Conostichus]]'', ''[[Pteridinium]]'', ''Palaeoplatoda'', ''[[Phyllozoon]]'' and ''Bergaueria'' and ''[[Chuaria]]'' have been conjectured.<ref name="Bland1984"/> Spheroidal objects found along with ''Arumberia'' have also been interpreted as "dispersable stage" of ''Arumberia'' itself.<ref name="Bland1984"/> ''Arumberia'' has been interpreted as a microbial mat morphotype developed in response to environmental perturbations in terminal Ediacaran shallow marine basins<ref name=":1" />


Conversely, a non biological interpretation has been put forward<ref name="McIlroy1997"/><ref name="Brasier1979">{{cite book|title=The origin of major invertebrate groups|last=Brasier, M. D.|publisher=Academic Press|year=1979|location=London, New York|pages=103–159|chapter=The Cambrian radiation event}}</ref> Past experiments reproduced ''Arumberia''-like traces from [[flume]] experiments<ref name="Walton1965">{{cite book|title=Sedimentary Features of Flysch and Greywackes|last=Walton, E.K.|first=Dzulynski, S.|publisher=Elsevier|year=1965|location=Amsterdam|pages=282}}</ref> and from the flux of water around small objects.<ref name="Allen1982">{{cite book|title=Sedimentary structures, their character and physical basis. Part II.|last=Allen, J.R.L.|publisher=Elsevier|year=1982|location=Amsterdam|pages=1–676}}</ref> The absence of ''Arumberia''-like structures after the Ediacaran period could be due to the unique properties of the [[microbial mat]] that covered the sea floor at the period.<ref name="McIlroy1997"/> However, there is still debate, with recent analysis of Urals' ''Arumberia''-like structures leaning towards a biological interpretation as an organism adapted to shallow water environments.<ref name="Kolesnikov2012"/> The [[rugae]] of ''Arumberia'' are considered to form from exclusively biological processes as observed in modern microbial mats<ref name=":1" /> and not from sediment desiccation, cracking or other abiotic processes. Fine wisps of organic material have been observed in thin section of ''Arumberia'' cut perpendicular to bedding planes,<ref name=":2" /> further suggesting that Arumberia was a living organism.
Conversely, a non biological interpretation has been put forward<ref name="McIlroy1997"/><ref name="Brasier1979">{{cite book|title=The origin of major invertebrate groups|last=Brasier, M. D.|publisher=Academic Press|year=1979|location=London, New York|pages=103–159|chapter=The Cambrian radiation event}}</ref> Past experiments reproduced ''Arumberia''-like traces from [[flume]] experiments<ref name="Walton1965">{{cite book|title=Sedimentary Features of Flysch and Greywackes|last1=Dzulynski |first1=S. |last2=Walton |first2=E. K.|publisher=Elsevier|year=1965|location=Amsterdam|pages=282|isbn=9780080869179}}</ref> and from the flux of water around small objects.<ref name="Allen1982">{{cite book|title=Sedimentary structures, their character and physical basis. Part II.|last=Allen |first=J. R. L.|publisher=Elsevier|year=1982|location=Amsterdam|pages=1–676}}</ref> The absence of ''Arumberia''-like structures after the Ediacaran period could be due to the unique properties of the [[microbial mat]] that covered the sea floor at the period.<ref name="McIlroy1997"/> However, there is still debate, with recent analysis of Urals' ''Arumberia''-like structures leaning towards a biological interpretation as an organism adapted to shallow water environments.<ref name="Kolesnikov2012"/> The [[rugae]] of ''Arumberia'' are considered to form from exclusively biological processes as observed in modern microbial mats<ref name=":1" /> and not from sediment desiccation, cracking or other abiotic processes. Fine wisps of organic material have been observed in thin section of ''Arumberia'' cut perpendicular to bedding planes,<ref name=":2" /> further suggesting that Arumberia was a living organism.


Recent work describes ''Arumberia'' as the fossilized remains of highly organized shallow marine microbial colonies;<ref name=":02"/><ref name=":1" /><ref>{{cite journal | doi=10.1016/j.precamres.2015.03.011 | title=Ediacaran biota in the aftermath of the Kotlinian Crisis: Asha Group of the South Urals | year=2015 | last1=Kolesnikov | first1=Anton V. | last2=Marusin | first2=Vasiliy V. | last3=Nagovitsin | first3=Konstantin E. | last4=Maslov | first4=Andrey V. | last5=Grazhdankin | first5=Dmitriy V. | journal=Precambrian Research | volume=263 | pages=59–78 }}</ref> a [[Microbially induced sedimentary structure|microbially-induced sedimentary structure]] (MISS),;<ref name=":2" /><ref name=":4">{{cite journal | jstor=3515360 | title=Microbial Mats in Terminal Proterozoic Siliciclastics: Ediacaran Death Masks | last1=Gehling | first1=James G. | journal=PALAIOS | year=1999 | volume=14 | issue=1 | pages=40–57 | doi=10.2307/3515360 }}</ref><ref>{{cite journal |last1=Kumar |DUPLICATE_first=S. |last2=Pandey |first1=S. K. |year=2008 |title=Arumberia banksi and associated fossils from the Neoproterozoic Maihar Sandstone, Vindhyan Supergroup, Central India |url=https://www.researchgate.net/publication/245542326 |journal=Journal of the Palaeontological Society of India |volume=53 |issue=1 |pages=83–97}}</ref><ref name="Pandey2009"/><ref>{{cite journal | doi=10.1016/j.jseaes.2014.01.009 | title=Microbially induced sedimentary structures (MISS) from the Ediacaran Jodhpur Sandstone, Marwar Supergroup, western Rajasthan | year=2014 | last1=Kumar | first1=S. | last2=Ahmad | first2=S. | journal=Journal of Asian Earth Sciences | volume=91 | pages=352–361 }}</ref> a series of slide marks underneath tough biomats that were exposed to tractional currents carrying sediment,<ref>Seilacher A. (2007). – Trace fossil analysis. – Springer-Verlag (Berlin).</ref> or a biopolymer-bearing [[Lichen|lichenized fungi]].<ref name=":5">{{cite journal | jstor=2401233 | title=Were the Ediacaran Fossils Lichens? |url=https://bpb-us-e1.wpmucdn.com/blogs.uoregon.edu/dist/d/3735/files/2013/07/retallack_2012_microbial_mat_and_earth-22khfla.pdf | last1=Retallack | first1=Gregory J. | journal=Paleobiology | year=1994 | volume=20 | issue=4 | pages=523–544 | doi=10.1017/S0094837300012975 | s2cid=129180481 }}</ref><ref name=":6">{{cite book | doi=10.2110/sepmsp.101.139 | chapter=Criteria for Distinguishing Microbial Mats and Earths | title=Microbial Mats in Silicilastic Depositional Systems Through Time | year=2012 | last1=Retallack | first1=Gregory J. | pages=139–152 | isbn=978-1-56576-314-2 }}</ref><ref name=":7">{{cite journal | doi=10.1111/j.1365-3091.2011.01302.x | title=Were Ediacaran siliciclastics of South Australia coastal or deep marine? | year=2012 | last1=Retallack | first1=Gregory J. | journal=Sedimentology | volume=59 | issue=4 | pages=1208–1236 | s2cid=129547681 }}</ref><ref name=":8">{{cite journal | doi=10.1038/nature11777 | title=Ediacaran life on land | year=2013 | last1=Retallack | first1=Gregory J. | journal=Nature | volume=493 | issue=7430 | pages=89–92 | pmid=23235827 | s2cid=205232092 }}</ref> As such, ''Arumberia'' structures remain an enigmatic Ediacaran fossil.
Recent work describes ''Arumberia'' as the fossilized remains of highly organized shallow marine microbial colonies;<ref name=Kolesnikov2012/><ref name=":1" /><ref>{{cite journal | doi=10.1016/j.precamres.2015.03.011 | title=Ediacaran biota in the aftermath of the Kotlinian Crisis: Asha Group of the South Urals | year=2015 | last1=Kolesnikov | first1=A. V. | last2=Marusin | first2=V. V. | last3=Nagovitsin | first3=K. E. | last4=Maslov | first4=A. V. | last5=Grazhdankin | first5=D. V. | journal=Precambrian Research | volume=263 | pages=59–78 | bibcode=2015PreR..263...59K }}</ref> a [[Microbially induced sedimentary structure|microbially-induced sedimentary structure]] (MISS),;<ref name=":2" /><ref name=":4">{{cite journal | jstor=3515360 | title=Microbial Mats in Terminal Proterozoic Siliciclastics: Ediacaran Death Masks | last1=Gehling | first1=J. G. | journal=PALAIOS | year=1999 | volume=14 | issue=1 | pages=40–57 | doi=10.2307/3515360 | bibcode=1999Palai..14...40G }}</ref><ref>{{cite journal |last1=Kumar |first1=S. |last2=Pandey |first2=S. K. |year=2008 |title=Arumberia banksi and associated fossils from the Neoproterozoic Maihar Sandstone, Vindhyan Supergroup, Central India |url=https://www.researchgate.net/publication/245542326 |journal=Journal of the Palaeontological Society of India |volume=53 |issue=1 |pages=83–97}}</ref><ref name="Pandey2009"/><ref>{{cite journal | doi=10.1016/j.jseaes.2014.01.009 | title=Microbially induced sedimentary structures (MISS) from the Ediacaran Jodhpur Sandstone, Marwar Supergroup, western Rajasthan | year=2014 | last1=Kumar | first1=S. | last2=Ahmad | first2=S. | journal=Journal of Asian Earth Sciences | volume=91 | pages=352–361 | bibcode=2014JAESc..91..352K }}</ref> a series of slide marks underneath tough biomats that were exposed to tractional currents carrying sediment,<ref>Seilacher, A. (2007). – Trace fossil analysis. – Springer-Verlag (Berlin).</ref> or a biopolymer-bearing [[Lichen|lichenized fungi]].<ref name=":5">{{cite journal | jstor=2401233 | title=Were the Ediacaran Fossils Lichens? |url=https://bpb-us-e1.wpmucdn.com/blogs.uoregon.edu/dist/d/3735/files/2013/07/retallack_2012_microbial_mat_and_earth-22khfla.pdf | last1=Retallack | first1=G. J. | journal=Paleobiology | year=1994 | volume=20 | issue=4 | pages=523–544 | doi=10.1017/S0094837300012975 | bibcode=1994Pbio...20..523R | s2cid=129180481 }}</ref><ref name=":6">{{cite book | doi=10.2110/sepmsp.101.139 | chapter=Criteria for Distinguishing Microbial Mats and Earths | title=Microbial Mats in Silicilastic Depositional Systems Through Time |series=SEPM Special Publication |volume=101 | year=2012 | last1=Retallack | first1=G. J. |editor1=Nora Noffke |editor2=Henry Chafetz| pages=139–152 | isbn=978-1-56576-314-2 }}</ref><ref name=":7">{{cite journal | doi=10.1111/j.1365-3091.2011.01302.x | title=Were Ediacaran siliciclastics of South Australia coastal or deep marine? | year=2012 | last1=Retallack | first1=G. J. | journal=Sedimentology | volume=59 | issue=4 | pages=1208–1236 | bibcode=2012Sedim..59.1208R | s2cid=129547681 }}</ref><ref name=":8">{{cite journal | doi=10.1038/nature11777 | title=Ediacaran life on land | year=2013 | last1=Retallack | first1=G. J. | journal=Nature | volume=493 | issue=7430 | pages=89–92 | pmid=23235827 | bibcode=2013Natur.493...89R | s2cid=205232092 }}</ref> As such, ''Arumberia'' structures remain an enigmatic Ediacaran fossil.


== Taphonomy ==
==Taphonomy==


=== Facies ===
===Facies===
The Ediacaran [[facies]] where Arumberia has been found are interpreted as [[Terrigenous sediment|terrigenous]] sedimentary rocks in shallow marine<ref>{{cite journal | doi=10.1016/S0301-9268(99)00069-8 | title=Environmental interpretation and a sequence stratigraphic framework for the terminal Proterozoic Ediacara Member within the Rawnsley Quartzite, South Australia | year=2000 | last1=Gehling | first1=J.G. | journal=Precambrian Research | volume=100 | issue=1–3 | pages=65–95 }}</ref><ref>{{cite journal | doi=10.18814/epiiugs/2012/v35i1/023 | title=Ediacaran stratigraphy and the biota of the Adelaide Geosyncline, South Australia | year=2012 | last1=Gehling | first1=James G. | last2=Droser | first2=Mary L. | journal=Episodes | volume=35 | pages=236–246 | s2cid=129497585 }}</ref><ref name=":9">{{cite journal | doi=10.1038/s41467-018-04195-8 | title=Ediacara biota flourished in oligotrophic and bacterially dominated marine environments across Baltica | year=2018 | last1=Pehr | first1=Kelden | last2=Love | first2=Gordon D. | last3=Kuznetsov | first3=Anton | last4=Podkovyrov | first4=Victor | last5=Junium | first5=Christopher K. | last6=Shumlyanskyy | first6=Leonid | last7=Sokur | first7=Tetyana | last8=Bekker | first8=Andrey | journal=Nature Communications | volume=9 | issue=1 | page=1807 | pmid=29728614 | pmc=5935690 }}</ref> or fluviolacustrine (intertidal or delta plain) settings<ref name=":1" /> that may have been affected by desiccation and salinity.<ref>{{cite journal | doi=10.1051/bsgf/2017001 | title=An introduction to the special issue of the BSGF | year=2017 | last1=Danelian | first1=Taniel | last2=Jolivet | first2=Marc | last3=Ionov | first3=Dmitri | journal=Bulletin de la Société Géologique de France | volume=188 | issue=1–2 | pages=E1 }}</ref> However, an alternative interpretation of the Ediacaran facies where ''Arumberia'' is found is that they were coastal gyspiferous [[paleosol]]s of intertidal to [[Supratidal zone|supratidal]] settings.<ref name=":6" /><ref name=":7" /><ref name=":8" /> Terminal Ediacaran (560 Ma) facies in Baltica dominantly contain [[biomarker]]s (hopane and sterane ratios) characteristic of bacterially-dominated communities in shallow marine [[oligotroph]]ic settings.<ref name=":9" /> These values reflect a high ratio of bacterial to eukaryotic biomass and suggest these ecosystems were nutrient-limited and dominated by bacterial communities, which may have imposed growth constraints and evolutionary modifications to Ediacaran organisms like ''Arumberia.''
The Ediacaran [[facies]] where Arumberia has been found are interpreted as [[Terrigenous sediment|terrigenous]] sedimentary rocks in shallow marine<ref>{{cite journal | doi=10.1016/S0301-9268(99)00069-8 | title=Environmental interpretation and a sequence stratigraphic framework for the terminal Proterozoic Ediacara Member within the Rawnsley Quartzite, South Australia | year=2000 | last1=Gehling | first1=J. G. | journal=Precambrian Research | volume=100 | issue=1–3 | pages=65–95 | bibcode=2000PreR..100...65G }}</ref><ref>{{cite journal | doi=10.18814/epiiugs/2012/v35i1/023 | title=Ediacaran stratigraphy and the biota of the Adelaide Geosyncline, South Australia | year=2012 | last1=Gehling | first1=J. G. | last2=Droser | first2=M. L. | journal=Episodes | volume=35 | pages=236–246 | doi-broken-date=6 December 2024 | s2cid=129497585 | doi-access=free }}</ref><ref name=":9">{{cite journal | doi=10.1038/s41467-018-04195-8 | title=Ediacara biota flourished in oligotrophic and bacterially dominated marine environments across Baltica | year=2018 | last1=Pehr | first1=K. | last2=Love | first2=G. D. | last3=Kuznetsov | first3=A. | last4=Podkovyrov | first4=V. | last5=Junium | first5=C. K. | last6=Shumlyanskyy | first6=L. | last7=Sokur | first7=T. | last8=Bekker | first8=A. | journal=Nature Communications | volume=9 | issue=1 | page=1807 | pmid=29728614 | pmc=5935690 | bibcode=2018NatCo...9.1807P }}</ref> or fluviolacustrine (intertidal or delta plain) settings<ref name=":1" /> that may have been affected by desiccation and salinity.<ref>{{cite journal | doi=10.1051/bsgf/2017001 | title=An introduction to the special issue of the BSGF | year=2017 | last1=Danelian | first1=T. | last2=Jolivet | first2=M. | last3=Ionov | first3=D. | journal=Bulletin de la Société Géologique de France | volume=188 | issue=1–2 | pages=E1 | doi-access=free }}</ref> However, an alternative interpretation of the Ediacaran facies where ''Arumberia'' is found is that they were coastal gypsiferous [[paleosol]]s of intertidal to [[Supratidal zone|supratidal]] settings.<ref name=":6" /><ref name=":7" /><ref name=":8" /> Terminal Ediacaran (560 Ma) facies in Baltica dominantly contain [[biomarker]]s (hopane and sterane ratios) characteristic of bacterially-dominated communities in shallow marine [[oligotroph]]ic settings.<ref name=":9" /> These values reflect a high ratio of bacterial to eukaryotic biomass and suggest these ecosystems were nutrient-limited and dominated by bacterial communities, which may have imposed growth constraints and evolutionary modifications to Ediacaran organisms like ''Arumberia.''


=== Burial Compaction and [[Diagenesis]]===
===Burial compaction and [[diagenesis]]===
The original interpretation of ''Arumberia'' as a conical or cup-shaped depression structure is contrary to modern interpretations of ''Arumberia'' as a bulge or impression.<ref name=":11" /> Extensive burial from overburden typical in areas where ''Arumberia'' is found would greatly compact any bulge or depression of a typical soft-bodied marine [[Animal|metazoan]]; however, it has been suggested that diagenic [[silicification]], ferrugination or [[pyritization]] can provide critical fossil rigidity during burial <ref name=":3" /><ref name=":10">{{cite journal | doi=10.1130/G38542.1 | title=Exceptional preservation of soft-bodied Ediacara Biota promoted by silica-rich oceans | year=2016 | last1=Tarhan | first1=Lidya G. | last2=Hood | first2=Ashleigh v.S. | last3=Droser | first3=Mary L. | last4=Gehling | first4=James G. | last5=Briggs | first5=Derek E.G. | journal=Geology | volume=44 | issue=11 | pages=951–954 }}</ref><ref name=":11">{{cite journal | doi=10.1016/j.precamres.2006.05.007 | title=Ediacaran fossil preservation: Taphonomy and diagenesis of a discoid biota from the Amadeus Basin, central Australia | year=2006 | last1=Mapstone | first1=N.B. | last2=McIlroy | first2=D. | journal=Precambrian Research | volume=149 | issue=3–4 | pages=126–148 }}</ref> which supports the soft-body marine metazoan description of ''Arumberia''. The presence of pyrite may impart significant resistance to burial compaction<ref name=":4" /><ref name=":11" /><ref>{{cite journal |doi=10.1127/njgpm/2002/2002/385 |url=http://www.biol.uw.edu.pl/ewolucja/ludzie/81.pdf |title=Internal anatomy of a new Precambrian dickinsoniid dipleurozoan from northern Russia |year=2002 |last1=Dzik |first1=Jerzy |last2=Ivantsov |first2=Andrey Yu. |journal=Neues Jahrbuch für Geologie und Paläontologie - Monatshefte |volume=2002 |issue=7 |pages=385–396 }}</ref><ref>{{cite journal | doi=10.2110/palo.2015.095 | title=Framboidal Pyrite Shroud Confirms the 'Death Mask' Model for Moldic Preservation of Ediacaran Soft-Bodied Organisms | year=2016 | last1=Liu | first1=Alexander G. | journal=PALAIOS | volume=31 | issue=5 | pages=259–274 | hdl=1983/535d288a-68ee-4481-8553-6b7d2e45dacb | s2cid=132601490 }}</ref> in ''Arumberia'', but to date no study has demonstrated a thick pyritic film of sufficient strength to withstand burial compaction above an unpyritized Ediacaran fossil,<ref>{{cite journal | doi=10.2110/palo.2015.095 | title=Framboidal Pyrite Shroud Confirms the 'Death Mask' Model for Moldic Preservation of Ediacaran Soft-Bodied Organisms | year=2016 | last1=Liu | first1=Alexander G. | journal=PALAIOS | volume=31 | issue=5 | pages=259–274 | hdl=1983/535d288a-68ee-4481-8553-6b7d2e45dacb | s2cid=132601490 }}</ref> which is thought to be a requirement for the preservational models that involve the pyritization of soft-body metazoans like ''Arumberia''.
The original interpretation of ''Arumberia'' as a conical or cup-shaped depression structure is contrary to modern interpretations of ''Arumberia'' as a bulge or impression.<ref name=":11" /> Extensive burial from overburden typical in areas where ''Arumberia'' is found would greatly compact any bulge or depression of a typical soft-bodied marine [[Animal|metazoan]]; however, it has been suggested that diagenic [[silicification]], ferrugination or [[pyritization]] can provide critical fossil rigidity during burial <ref name=":3" /><ref name=":10">{{cite journal | doi=10.1130/G38542.1 | title=Exceptional preservation of soft-bodied Ediacara Biota promoted by silica-rich oceans | year=2016 | last1=Tarhan | first1=L. G. | last2=Hood | first2=A. V. S. | last3=Droser | first3=M. L. | last4=Gehling | first4=J. G. | last5=Briggs | first5=D. E. G. | journal=Geology | volume=44 | issue=11 | pages=951–954 | bibcode=2016Geo....44..951T }}</ref><ref name=":11">{{cite journal | doi=10.1016/j.precamres.2006.05.007 | title=Ediacaran fossil preservation: Taphonomy and diagenesis of a discoid biota from the Amadeus Basin, central Australia | year=2006 | last1=Mapstone | first1=N. B. | last2=McIlroy | first2=D. | journal=Precambrian Research | volume=149 | issue=3–4 | pages=126–148 | bibcode=2006PreR..149..126M }}</ref> which supports the soft-body marine metazoan description of ''Arumberia''. The presence of pyrite may impart significant resistance to burial compaction<ref name=":4" /><ref name=":11" /><ref>{{cite journal |doi=10.1127/njgpm/2002/2002/385 |url=http://www.biol.uw.edu.pl/ewolucja/ludzie/81.pdf |title=Internal anatomy of a new Precambrian dickinsoniid dipleurozoan from northern Russia |year=2002 |last1=Dzik |first1=J. |last2=Ivantsov |first2=A. Yu. |journal=Neues Jahrbuch für Geologie und Paläontologie - Monatshefte |volume=2002 |issue=7 |pages=385–396 |access-date=2018-06-14 |archive-date=2018-06-15 |archive-url=https://web.archive.org/web/20180615032203/http://www.biol.uw.edu.pl/ewolucja/ludzie/81.pdf |url-status=dead }}</ref><ref name="Liu 2016">{{cite journal | doi=10.2110/palo.2015.095 | title=Framboidal Pyrite Shroud Confirms the 'Death Mask' Model for Moldic Preservation of Ediacaran Soft-Bodied Organisms | year=2016 | last1=Liu | first1=A. G. | journal=PALAIOS | volume=31 | issue=5 | pages=259–274 | bibcode=2016Palai..31..259L | hdl=1983/535d288a-68ee-4481-8553-6b7d2e45dacb | s2cid=132601490 | url=https://research-information.bris.ac.uk/en/publications/535d288a-68ee-4481-8553-6b7d2e45dacb | hdl-access=free }}</ref> in ''Arumberia'', but to date no study has demonstrated a thick pyritic film of sufficient strength to withstand burial compaction above an unpyritized Ediacaran fossil,<ref name="Liu 2016"/> which is thought to be a requirement for the preservational models that involve the pyritization of soft-body metazoans like ''Arumberia''.


Analysis of thin sections of ''Arumberia'' show remarkable resistance to compaction, which may have been due to the presence of a pyrite sole-veneer.<ref name=":11" /> The [[Diagenesis|diagenetic]] oxidation of pyrite to hematite can remove all traces of the pyrite sole-veneer,<ref name=":11" /> so it is difficult to determine the true influence of pyritization on burial compaction in ''Arumberia''. Alternatively, the remarkable resistance to burial compaction may be due to the presence of a resistant biopolymer like [[chitin]] which is typical in [[Marine fungi|marine]] and [[Lichen|terrestrial]] lichens alike<ref name=":5" /><ref name=":8" /> Exactly how the fossils are preserved remains controversial, and more research into the taphonomy of Arumberia and other Ediacarans is needed.<ref name=":10" />
Analysis of thin sections of ''Arumberia'' show remarkable resistance to compaction, which may have been due to the presence of a pyrite sole-veneer.<ref name=":11" /> The [[Diagenesis|diagenetic]] oxidation of pyrite to hematite can remove all traces of the pyrite sole-veneer,<ref name=":11" /> so it is difficult to determine the true influence of pyritization on burial compaction in ''Arumberia''. Alternatively, the remarkable resistance to burial compaction may be due to the presence of a resistant biopolymer like [[chitin]] which is typical in [[Marine fungi|marine]] and [[Lichen|terrestrial]] lichens alike<ref name=":5" /><ref name=":8" /> Exactly how the fossils are preserved remains controversial, and more research into the taphonomy of Arumberia and other Ediacarans is needed.<ref name=":10" />

Latest revision as of 04:00, 9 December 2024

Arumberia
Temporal range: Late Ediacaran
Holotype specimen of Arumberia banksi, a convex hyporelief on the base of a sandstone bed from the Ediacaran Arumbera Sandstone near Alice Springs, Australia
Scientific classification Edit this classification
Kingdom: Incertae sedis
Genus: †Arumberia
Glaessner et Walter, 1975
Type species
Arumberia banksi
Glaessner et Walter, 1975
Species
    • A. banksi
    • A. vindhyanensis
    • A. usvaensis
    • A. multykensis
    • A. beckeri
    • A. ollii

    Arumberia is an enigmatic fossil from the Ediacaran period[1] originally described from the Arumbera Sandstone, Northern Territory, Australia[2] but also found in the Urals,[3] East Siberia,[4] England and Wales,[5] Northern France,[5] the Avalon Peninsula,[5] India[6] and Brazil.[7] Several morphologically distinct species are recognized.[3][8]

    Description

    [edit]

    Initially discovered by Glaessner and Walter (1975), Arumberia was described as a problematic cupped-body fossil of an Ediacaran soft-bodied organism characterized by hollow compressible ribbed bodies composed of flexible tissue. Brasier (1979) deemed it a pseudofossil arising from turbid water flow in shallow marine or deltaic environments, due in part to physical and morphological similarities to flume-induced structures previously observed by Dzulynski and Walton (1965). Arumberia appears as a poorly-delimited series of fine parallel grooves arising from a single region or point. Arumberia banksii consists of an array of straight to gently curved parallel to subparallel ridges (rugae) about 1 – 3 mm wide and separated by flat to gently concave furrows of 1 – 7 mm in width. Relief from ridge top to furrow bottom is less than 1 mm. Ridge ranges in length from 1.5 cm to 14.5 cm. Generally the ridges are parallel, but they also bifurcate. Ridges are developed on plane and rippled surfaces.[6]

    List of species

    [edit]

    There are four species of Arumberia that have been formally recognized. Arumberia banksi has thin siliciclastic biolaminites known as rugose structures[3] including those with subparallel or fanning-out series of rugae (Arumberia banksi s.str.) and sub-parallel series of branching rugae (Arumberia vindhyanensis).[3] The Arumberia multykensis variety is found in greenish gray siltstones as series of near-parallel ridges with positive hyporelief up to 1 mm wide and 0.5 mm high, with 10 mm spacing between the ridges[3] while A. usavaensis occurs as a series of near parallel ridges on the wavy surfaces on linguoid ripple marks which stretch along the paleoflow direction and flatten out as microterraces on the leeward side of the ripples.[3] Arumberia usavensis is found on both upper and lower surfaces of sandstone beds as well as inside sandstones and siltstones.[3] Arumberia beckeri and Arumberia ollii are morphologically distinct from A. banksi[3] and are filamentous and ribbon-shaped compressed macrofossils which host authigenic clay minerals and are most likely unrelated to Arumberia.[8]

    Another specimen of Arumberia banksi, a convex hyporelief on the base of a sandstone bed from the Ediacaran Arumbera Sandstone near Alice Springs, Australia
    Side view of holotype specimen of Arumberia banksi, a convex hyporelief on the base of the sandstone bed from the Ediacaran Arumbera Sandstone near Alice Springs, Australia

    Locations

    [edit]

    Arumberia was first described in Neoproterozoic red sandstones of the lower Arumbera sandstone formation of the Amadeus Basin in Northern Territory, Australia.[2] It has since been found in Argentina, Newfoundland, England, Wales, northeastern Europe, the eastern Sayan Mountains in Russia, Central India, and Rajasthan.[5][6][3][8][9][10] In addition, Arumberia has been reported from lower Palaeozoic strata in Brittany, France[5][10] and from the Upper Ediacaran Cerro Negro Formation in Argentina.[9]

    Identity

    [edit]

    The identity of Arumberia is controversial. Arumberia has been originally interpreted as a 5–20 cm high cup-like organism, apparently composed of flexible tissue, attached to the sea bottom by a blunt apex[2] or, later, as a colonial organism made of flexible, thin-walled tubes tightly joined through their length.[5] Affinities with Ernietta, Conostichus, Pteridinium, Palaeoplatoda, Phyllozoon and Bergaueria and Chuaria have been conjectured.[5] Spheroidal objects found along with Arumberia have also been interpreted as "dispersable stage" of Arumberia itself.[5] Arumberia has been interpreted as a microbial mat morphotype developed in response to environmental perturbations in terminal Ediacaran shallow marine basins[8]

    Conversely, a non biological interpretation has been put forward[1][11] Past experiments reproduced Arumberia-like traces from flume experiments[12] and from the flux of water around small objects.[13] The absence of Arumberia-like structures after the Ediacaran period could be due to the unique properties of the microbial mat that covered the sea floor at the period.[1] However, there is still debate, with recent analysis of Urals' Arumberia-like structures leaning towards a biological interpretation as an organism adapted to shallow water environments.[3] The rugae of Arumberia are considered to form from exclusively biological processes as observed in modern microbial mats[8] and not from sediment desiccation, cracking or other abiotic processes. Fine wisps of organic material have been observed in thin section of Arumberia cut perpendicular to bedding planes,[10] further suggesting that Arumberia was a living organism.

    Recent work describes Arumberia as the fossilized remains of highly organized shallow marine microbial colonies;[3][8][14] a microbially-induced sedimentary structure (MISS),;[10][15][16][6][17] a series of slide marks underneath tough biomats that were exposed to tractional currents carrying sediment,[18] or a biopolymer-bearing lichenized fungi.[19][20][21][22] As such, Arumberia structures remain an enigmatic Ediacaran fossil.

    Taphonomy

    [edit]

    Facies

    [edit]

    The Ediacaran facies where Arumberia has been found are interpreted as terrigenous sedimentary rocks in shallow marine[23][24][25] or fluviolacustrine (intertidal or delta plain) settings[8] that may have been affected by desiccation and salinity.[26] However, an alternative interpretation of the Ediacaran facies where Arumberia is found is that they were coastal gypsiferous paleosols of intertidal to supratidal settings.[20][21][22] Terminal Ediacaran (560 Ma) facies in Baltica dominantly contain biomarkers (hopane and sterane ratios) characteristic of bacterially-dominated communities in shallow marine oligotrophic settings.[25] These values reflect a high ratio of bacterial to eukaryotic biomass and suggest these ecosystems were nutrient-limited and dominated by bacterial communities, which may have imposed growth constraints and evolutionary modifications to Ediacaran organisms like Arumberia.

    Burial compaction and diagenesis

    [edit]

    The original interpretation of Arumberia as a conical or cup-shaped depression structure is contrary to modern interpretations of Arumberia as a bulge or impression.[27] Extensive burial from overburden typical in areas where Arumberia is found would greatly compact any bulge or depression of a typical soft-bodied marine metazoan; however, it has been suggested that diagenic silicification, ferrugination or pyritization can provide critical fossil rigidity during burial [9][28][27] which supports the soft-body marine metazoan description of Arumberia. The presence of pyrite may impart significant resistance to burial compaction[15][27][29][30] in Arumberia, but to date no study has demonstrated a thick pyritic film of sufficient strength to withstand burial compaction above an unpyritized Ediacaran fossil,[30] which is thought to be a requirement for the preservational models that involve the pyritization of soft-body metazoans like Arumberia.

    Analysis of thin sections of Arumberia show remarkable resistance to compaction, which may have been due to the presence of a pyrite sole-veneer.[27] The diagenetic oxidation of pyrite to hematite can remove all traces of the pyrite sole-veneer,[27] so it is difficult to determine the true influence of pyritization on burial compaction in Arumberia. Alternatively, the remarkable resistance to burial compaction may be due to the presence of a resistant biopolymer like chitin which is typical in marine and terrestrial lichens alike[19][22] Exactly how the fossils are preserved remains controversial, and more research into the taphonomy of Arumberia and other Ediacarans is needed.[28]

    See also

    [edit]

    References

    [edit]
    1. ^ a b c McIlroy, D.; Walter, M. (1997). "A reconsideration of the biogenicity of Arumberia banksi Glaessner & Walter". Alcheringa: An Australasian Journal of Palaeontology. 21 (1): 79–80. Bibcode:1997Alch...21...79M. doi:10.1080/03115519708619187.
    2. ^ a b c Glaessner, M. F.; Walter, M. R. (1975). "New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia". Alcheringa: An Australasian Journal of Palaeontology. 1 (1): 59–69. Bibcode:1975Alch....1...59G. doi:10.1080/03115517508619480.
    3. ^ a b c d e f g h i j k Kolesnikov, A. V.; Grazhdankin, D. V.; Maslov, A. V. (2012). "Arumberia-type structures in the Upper Vendian of the Urals". Doklady Earth Sciences. 447 (1): 1233–1239. Bibcode:2012DokES.447.1233K. doi:10.1134/S1028334X12110013. S2CID 140695807. Retrieved 27 January 2013.
    4. ^ Bogolepova, O. K.; Gubanov, A. P.; Howard, J. P.; Gómez-Pérez, M. (2010). "Arumberia and other microbial mats from the Neoproterozoic-Cambrian strata of East Siberia". Geophysical Research Abstracts. 12: 3143. Bibcode:2010EGUGA..12.3143B.
    5. ^ a b c d e f g h Bland, B. H. (1984). "Arumberia Glaessner & Walter, a review of its potential for correlation in the region of the Precambrian–Cambrian boundary". Geological Magazine. 121 (6): 625–633. Bibcode:1984GeoM..121..625B. doi:10.1017/S0016756800030776. S2CID 128492261.
    6. ^ a b c d Kumar, S.; Pandey, S. K. (December 2009). "Note on the occurrence of Arumberia Banksi and associated fossils from the Jodhpur Sandstone, Marwar Supergroup, western Rajasthan" (PDF). Journal of the Paleontological Society of India. 54 (2): 171–178.
    7. ^ Becker-Kerber, Bruno; El Albani, Abderrazak; Konhauser, Kurt; Abd Elmola, Ahmed; Fontaine, Claude; Paim, Paulo S. G.; Mazurier, Arnaud; Prado, Gustavo M. E. M.; Galante, Douglas; Kerber, Pedro B.; da Rosa, Ana L. Z.; Fairchild, Thomas R.; Meunier, Alain; Pacheco, Mírian L. A. F. (2021-03-03). "The role of volcanic-derived clays in the preservation of Ediacaran biota from the Itajaí Basin (ca. 563 Ma, Brazil)". Scientific Reports. 11 (1): 5013. doi:10.1038/s41598-021-84433-0. ISSN 2045-2322. PMC 7930025. PMID 33658558.
    8. ^ a b c d e f g Kolesnikov, A. V.; Danelian, T.; Gommeaux, M.; Maslov, A. V.; Grazhdankin, D. V. (2017). "Arumberiamorph structure in modern microbial mats: Implications for Ediacaran palaeobiology". Bulletin de la Société Géologique de France. 188 (1–2): 5. doi:10.1051/bsgf/2017006.
    9. ^ a b c Arrouy, M. J.; Warren, L. V.; Quaglio, F.; Poiré, D. G.; Simões, M. G.; Rosa, M. B.; Peral, L. E. G. (2016). "Ediacaran discs from South America: Probable soft-bodied macrofossils unlock the paleogeography of the Clymene Ocean". Scientific Reports. 6: 30590. Bibcode:2016NatSR...630590A. doi:10.1038/srep30590. PMC 4962044. PMID 27460966.
    10. ^ a b c d Davies, N. S.; Liu, A. G.; Gibling, M. R.; Miller, R. F. (2016). "Resolving MISS conceptions and misconceptions: A geological approach to sedimentary surface textures generated by microbial and abiotic processes". Earth-Science Reviews. 154: 210–246. Bibcode:2016ESRv..154..210D. doi:10.1016/j.earscirev.2016.01.005. hdl:1983/bd67cb45-b022-4db0-be3d-b2977d2b81ab. S2CID 56345018.
    11. ^ Brasier, M. D. (1979). "The Cambrian radiation event". The origin of major invertebrate groups. London, New York: Academic Press. pp. 103–159.
    12. ^ Dzulynski, S.; Walton, E. K. (1965). Sedimentary Features of Flysch and Greywackes. Amsterdam: Elsevier. p. 282. ISBN 9780080869179.
    13. ^ Allen, J. R. L. (1982). Sedimentary structures, their character and physical basis. Part II. Amsterdam: Elsevier. pp. 1–676.
    14. ^ Kolesnikov, A. V.; Marusin, V. V.; Nagovitsin, K. E.; Maslov, A. V.; Grazhdankin, D. V. (2015). "Ediacaran biota in the aftermath of the Kotlinian Crisis: Asha Group of the South Urals". Precambrian Research. 263: 59–78. Bibcode:2015PreR..263...59K. doi:10.1016/j.precamres.2015.03.011.
    15. ^ a b Gehling, J. G. (1999). "Microbial Mats in Terminal Proterozoic Siliciclastics: Ediacaran Death Masks". PALAIOS. 14 (1): 40–57. Bibcode:1999Palai..14...40G. doi:10.2307/3515360. JSTOR 3515360.
    16. ^ Kumar, S.; Pandey, S. K. (2008). "Arumberia banksi and associated fossils from the Neoproterozoic Maihar Sandstone, Vindhyan Supergroup, Central India". Journal of the Palaeontological Society of India. 53 (1): 83–97.
    17. ^ Kumar, S.; Ahmad, S. (2014). "Microbially induced sedimentary structures (MISS) from the Ediacaran Jodhpur Sandstone, Marwar Supergroup, western Rajasthan". Journal of Asian Earth Sciences. 91: 352–361. Bibcode:2014JAESc..91..352K. doi:10.1016/j.jseaes.2014.01.009.
    18. ^ Seilacher, A. (2007). – Trace fossil analysis. – Springer-Verlag (Berlin).
    19. ^ a b Retallack, G. J. (1994). "Were the Ediacaran Fossils Lichens?" (PDF). Paleobiology. 20 (4): 523–544. Bibcode:1994Pbio...20..523R. doi:10.1017/S0094837300012975. JSTOR 2401233. S2CID 129180481.
    20. ^ a b Retallack, G. J. (2012). "Criteria for Distinguishing Microbial Mats and Earths". In Nora Noffke; Henry Chafetz (eds.). Microbial Mats in Silicilastic Depositional Systems Through Time. SEPM Special Publication. Vol. 101. pp. 139–152. doi:10.2110/sepmsp.101.139. ISBN 978-1-56576-314-2.
    21. ^ a b Retallack, G. J. (2012). "Were Ediacaran siliciclastics of South Australia coastal or deep marine?". Sedimentology. 59 (4): 1208–1236. Bibcode:2012Sedim..59.1208R. doi:10.1111/j.1365-3091.2011.01302.x. S2CID 129547681.
    22. ^ a b c Retallack, G. J. (2013). "Ediacaran life on land". Nature. 493 (7430): 89–92. Bibcode:2013Natur.493...89R. doi:10.1038/nature11777. PMID 23235827. S2CID 205232092.
    23. ^ Gehling, J. G. (2000). "Environmental interpretation and a sequence stratigraphic framework for the terminal Proterozoic Ediacara Member within the Rawnsley Quartzite, South Australia". Precambrian Research. 100 (1–3): 65–95. Bibcode:2000PreR..100...65G. doi:10.1016/S0301-9268(99)00069-8.
    24. ^ Gehling, J. G.; Droser, M. L. (2012). "Ediacaran stratigraphy and the biota of the Adelaide Geosyncline, South Australia". Episodes. 35: 236–246. doi:10.18814/epiiugs/2012/v35i1/023 (inactive 6 December 2024). S2CID 129497585.{{cite journal}}: CS1 maint: DOI inactive as of December 2024 (link)
    25. ^ a b Pehr, K.; Love, G. D.; Kuznetsov, A.; Podkovyrov, V.; Junium, C. K.; Shumlyanskyy, L.; Sokur, T.; Bekker, A. (2018). "Ediacara biota flourished in oligotrophic and bacterially dominated marine environments across Baltica". Nature Communications. 9 (1): 1807. Bibcode:2018NatCo...9.1807P. doi:10.1038/s41467-018-04195-8. PMC 5935690. PMID 29728614.
    26. ^ Danelian, T.; Jolivet, M.; Ionov, D. (2017). "An introduction to the special issue of the BSGF". Bulletin de la Société Géologique de France. 188 (1–2): E1. doi:10.1051/bsgf/2017001.
    27. ^ a b c d e Mapstone, N. B.; McIlroy, D. (2006). "Ediacaran fossil preservation: Taphonomy and diagenesis of a discoid biota from the Amadeus Basin, central Australia". Precambrian Research. 149 (3–4): 126–148. Bibcode:2006PreR..149..126M. doi:10.1016/j.precamres.2006.05.007.
    28. ^ a b Tarhan, L. G.; Hood, A. V. S.; Droser, M. L.; Gehling, J. G.; Briggs, D. E. G. (2016). "Exceptional preservation of soft-bodied Ediacara Biota promoted by silica-rich oceans". Geology. 44 (11): 951–954. Bibcode:2016Geo....44..951T. doi:10.1130/G38542.1.
    29. ^ Dzik, J.; Ivantsov, A. Yu. (2002). "Internal anatomy of a new Precambrian dickinsoniid dipleurozoan from northern Russia" (PDF). Neues Jahrbuch für Geologie und Paläontologie - Monatshefte. 2002 (7): 385–396. doi:10.1127/njgpm/2002/2002/385. Archived from the original (PDF) on 2018-06-15. Retrieved 2018-06-14.
    30. ^ a b Liu, A. G. (2016). "Framboidal Pyrite Shroud Confirms the 'Death Mask' Model for Moldic Preservation of Ediacaran Soft-Bodied Organisms". PALAIOS. 31 (5): 259–274. Bibcode:2016Palai..31..259L. doi:10.2110/palo.2015.095. hdl:1983/535d288a-68ee-4481-8553-6b7d2e45dacb. S2CID 132601490.
    Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Arumberia&oldid=1262012182"