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Microfossils from the late Mesoproterozoic - early Neoproterozoic Atar/El Mreiti Group, Taoudeni Basin, Mauritania, northwestern Africa

Beghin, Jérémie; Storme, Jean-Yves; Blanpied, Christian; Gueneli, Nur; Brocks, Jochen; Poulton, Simon; Javaux, Emmanuelle J.

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The well-preserved Meso-Neoproterozoic shallow marine succession of the Atar/El Mreïti Group, in the Taoudeni Basin, Mauritania, offers a unique opportunity to investigate the mid-Proterozoic eukaryotic record in Western Africa. Previous investigations focused on stromatolites, biomarkers, chemostratigraphy and palaeoredox conditions. However, only a very modest diversity of organic-walled microfossils (acritarchs) has been documented. Here, we present a new, exquisitely well-preserved and...[Show more]

dc.contributor.authorBeghin, Jérémie
dc.contributor.authorStorme, Jean-Yves
dc.contributor.authorBlanpied, Christian
dc.contributor.authorGueneli, Nur
dc.contributor.authorBrocks, Jochen
dc.contributor.authorPoulton, Simon
dc.contributor.authorJavaux, Emmanuelle J.
dc.date.accessioned2021-05-27T02:58:16Z
dc.date.available2021-05-27T02:58:16Z
dc.identifier.issn0301-9268
dc.identifier.urihttp://hdl.handle.net/1885/234547
dc.description.abstractThe well-preserved Meso-Neoproterozoic shallow marine succession of the Atar/El Mreïti Group, in the Taoudeni Basin, Mauritania, offers a unique opportunity to investigate the mid-Proterozoic eukaryotic record in Western Africa. Previous investigations focused on stromatolites, biomarkers, chemostratigraphy and palaeoredox conditions. However, only a very modest diversity of organic-walled microfossils (acritarchs) has been documented. Here, we present a new, exquisitely well-preserved and morphologically diverse assemblage of organic-walled microfossils from three cores drilled through the Atar/El Mreïti Group. A total of 48 distinct entities including 11 unambiguous eukaryotes (ornamented and process-bearing acritarchs), and 37 taxonomically unresolved taxa (including 9 possible eukaryotes, 6 probable prokaryotes, and 22 other prokaryotic or eukaryotic taxa) were observed. Black shales preserve locally abundant fragments of organic-rich laminae interpreted as benthic microbial mats. We also document one of the oldest records of Leiosphaeridia kulgunica, a species showing a circular opening interpreted as a sophisticated circular excystment structure (a pylome), and one of the oldest records of Trachyhystrichosphaera aimika and T. botula, two distinctive process-bearing acritarchs present in well-dated 1.1 Ga formations at the base of the succession. The general assemblage composition and the presence of three possible index fossils (A. tetragonala, S. segmentata and T. aimika) support a late Mesoproterozoic to early Neoproterozoic (Tonian) age for the Atar/El Mreïti Group, consistent with published lithostratigraphy, chemostratigraphy and geochronology. This study provides the first evidence for a moderately diverse eukaryotic life, at least 1.1 billion years ago in Western Africa. Comparison with coeval worldwide assemblages indicates that a broadly similar microbial biosphere inhabited (generally redox-stratified) oceans, placing better time constraints on early eukaryote palaeogeography and biostratigraphy.
dc.description.sponsorshipResearch support from BELSPO IAP PLANET TOPERS to J. Beghin (PhD scholarship) and E.J. Javaux (PI), and European Research Council (ERC) Stg ELiTE FP7/308074 to J.-Y. Storme (postdoc fellowship) and E.J. Javaux (PI) are gratefully acknowledged. J.J. Brocks acknowledges support from the Australian Research Council (DP1095247).
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherElsevier
dc.rights© 2017 The Authors
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.sourcePrecambrian Research
dc.subjectMesoproterozoic
dc.subjectNeoproterozoic (Tonian)
dc.subjectAcritarchs
dc.subjectMicrofossils
dc.subjectEukaryotes
dc.subjectBiostratigraphy
dc.subjectPalaeogeography
dc.titleMicrofossils from the late Mesoproterozoic - early Neoproterozoic Atar/El Mreiti Group, Taoudeni Basin, Mauritania, northwestern Africa
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume291
dcterms.dateAccepted2017-01-08
dc.date.issued2017-04
local.identifier.absfor049999 - Earth Sciences not elsewhere classified
local.identifier.ariespublicationa383154xPUB5214
local.publisher.urlhttps://www.sciencedirect.com/
local.type.statusPublished Version
local.contributor.affiliationBeghin, Jérémie, University of Liège
local.contributor.affiliationStorme, Jean-Yves, University of Liège
local.contributor.affiliationBlanpied, Christian, University of Leeds
local.contributor.affiliationGueneli, Nur, College of Science, ANU
local.contributor.affiliationBrocks, Jochen, College of Science, ANU
local.contributor.affiliationPoulton, Simon, University of Leeds
local.contributor.affiliationJavaux, Emmanuelle J., University of Liège
dc.relationhttp://purl.org/au-research/grants/arc/DP1095247
local.bibliographicCitation.startpage63
local.bibliographicCitation.lastpage82
local.identifier.doi10.1016/j.precamres.2017.01.009
dc.date.updated2020-11-23T10:49:19Z
local.identifier.scopusID2-s2.0-85012260223
local.identifier.thomsonID000396959900004
dcterms.accessRightsOpen Access
dc.provenanceThis is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
dc.rights.licenseCC BY-NC-ND license
CollectionsANU Research Publications

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