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Gorbachikella grandiapertura


Classification: pf_mesozoic -> Praehedbergellidae -> Gorbachikella -> Gorbachikella grandiapertura
Sister taxa: G. depressa, G. grandiapertura, G. kugleri, G. neilii, G. sp.,

Taxonomy

Citation: Gorbachikella grandiapertura Boudagher-Fadel, Banner, Brown, Simmons, Gorbachik 1995
Rank: Species
Basionym: Gorbachikella grandiapertura
Taxonomic discussion: Gorbachikella grandiapertura basically differs from the other gorbachikellids in having an higher primary arch-like aperture and a wider umbilical area. [copied from Chronos database]

Type images:

Original description: Gorbachikella grandiapertura differs from G. kugleri in having a very convex spiral side, five chambers in the first whorl which reduces to four chambers in the whorl in the last two whorls (instead of only four chambers in each whorl throughout the test) and an axiointraumbilical aperture but with a much higher symmetrical (see Pl. 4 , fig. I b-2 b) to slightly asymetrical arch (see PI. 4 , fig. 3a, 4 b, 5a). 

Entries in the Catalog of original descriptions: Gorbachikella grandiapertura


Emended description: Test small to medium, trochospirally coiled, globigeriniform; 4 chambers in the outer whorl; chambers globular to subglobular increasing rather slowly and gradually in size as added; sutures depressed, radial and straight; peripheral outline round and lobate; umbilicus wide and shallow; dorsal side slightly to strongly convex; aperture umbilical as a high arch, possibly bordered by a narrow imperforate lip; wall calcareous, finely perforate, pores diameter usually comprised between 1 and 2mm; perforations unevenly distributed, widely-spaced and badly-defined in shape. [copied from Chronos database]

Geological Range:
Last occurrence (top): within Barremian Stage (126.30-130.77Ma, top in Barremian stage). Data source: [copied from Chronos database]
First occurrence (base): within Hauterivian Stage (130.77-133.88Ma, base in Hauterivian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Gorbachikella

    Character matrix

    test outline:Lobatechamber arrangement:Trochospiraledge view:Spiroconvexaperture:Umbilical
    sp chamber shape:Inflatedcoiling axis:Low-moderateperiphery:N/Aaperture border:Thin lip
    umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
    spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Finely Perforate: 1-2.5µm
    umbilical or test sutures:Moderately depressedfinal-whorl chambers:4.0-4.0 N.B. These characters are used for advanced search. N/A - not applicable

    References:

    BouDagher-Fadel, M., Banner, F. T., Bown, P. R., Simmons, M. D. & Gorbachik, T. N. (1995). Gorbachikella from the Hauterivian, Barremian-Aptian of Tunisia. Revue de Micropaléontologie. 38(3): 179-193. gs :: ::


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    Gorbachikella grandiapertura compiled by the pforams@mikrotax project team viewed: 10-8-2020

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    Short stable page link: http://mikrotax.org/pforams/index.php?id=110207 Go to Archive.is to create a permanent copy of this page - citation notes



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