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Planoheterohelix postmoremani


Classification: pf_mesozoic -> Heterohelicidae -> Planoheterohelix -> Planoheterohelix postmoremani
Sister taxa: P. globulosa, P. moremani, P. olssoni, P. papula, P. paraglobulosa, P. planata, P. postmoremani, P. praenuttallii, P. reussi, P. rumseyensis, P. sp.,

Taxonomy

Citation: Planoheterohelix postmoremani Georgescu & Huber 2009
Rank: Species
Basionym: Planoheterohelix postmoremani

Type images:

Original description: Test is biserial throughout and consists of 11 to 15 chambers. Small proloculus (8.2-14.3 microns) is followed by slightly larger second chamber. Chambers increase gradually in size as added. Earlier chambers are subglobular, those of adult stage are reniform and oblique to the test axis of growth. Sutures are distinct, depressed, and oblique. Tests are symmetrical in edge view, with broadly rounded periphery. Aperture is medium to high arch at base of lastformed chamber; it is bordered by two symmetrically developed periapertural flanges . Chamber surface is ornamented with closely spaced costae, each of them consisting of series of aligned pustules, resulting in a granular appearance. Test wall is calcitic, hyaline, microperforate; pore diameter ranges 0.5-0.9 microns.

Entries in the Catalog of original descriptions: Planoheterohelix postmoremani

Geological Range:
Last occurrence (top): within D. concavata zone (86.71-89.91Ma, top in Coniacian stage). Data source: [copied from Chronos database]
First occurrence (base): within R. cushmani zone (94.03-95.94Ma, base in Cenomanian 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: Planoheterohelix

    Character matrix

    test outline:Triangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
    sp chamber shape:Reniformcoiling axis:N/Aperiphery:N/Aaperture border:Thin flange
    umb chbr shape:Reniformumbilicus:N/Aperiph margin shape:Broadly roundedaccessory apertures:N/A
    spiral sutures:Moderately depressedumb depth:N/Awall texture:Finely costateshell porosity:Microperforate: <1┬Ám
    umbilical or test sutures:Moderately depressedfinal-whorl chambers:2.0-2.0 N.B. These characters are used for advanced search. N/A - not applicable

    References:

    Georgescu, M. D. & Huber, B. T. (2009). Early evolution of the Cretaceous serial planktic foraminifera (late Albian-Cenomanian). Journal of Foraminiferal Research. 39: 335-360. gs


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    Planoheterohelix postmoremani compiled by the pforams@mikrotax project team viewed: 22-10-2019

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    Short stable page link: http://mikrotax.org/pforams/index.php?id=110407 Go to Archive.is to create a permanent copy of this page - citation notes



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