nmn

Laeviheterohelix turgida


Classification: pf_mesozoic -> Heterohelicidae -> Laeviheterohelix -> Laeviheterohelix turgida
Sister taxa: L. dentata, L. flabelliformis, L. glabrans, L. pulchra, L. reniformis, L. turgida, L. sp.,

Taxonomy

Citation: Laeviheterohelix turgida Nederbragt 1991
Rank: Species
Basionym: Laeviheterohelix turgida
Taxonomic discussion: Laeviheterohelix turgida resembles its probable ancestor L. pulchra in its large apertural flanges and reniform chambers. It differs from L. pulchra in its deeper and more inflated test and its subacute periphery. The two species can be found in a single sample, but they form distinct populations without morphologic transitions. Laeviheterohelix turgida differs from L. dentata in its deeper test and larger apertural flanges.

Probably smooth forms of L. turgida could be found, just as in L. pulchra. However, all specimens encountered in this study have pore mounds (most of the samples from the El Kef section) or are recrystallized to the extent that the wall structure cannot be observed (some samples from El Kef and all of the Site 356 specimens). [copied from Chronos database]

Type images:

Original description: Test biserial throughout, wall microperforate, with pore mounds. Chambers inflated, subglobular in the juvenile, later becoming slightly reniform. Sides of test gently tapering; sutures deeply depressed. Individual chambers with greatest depth near the median suture, pinched near the periphery, to give a subacute periphery. Aperture bordered by elongate flanges, which extend to the opposite edge of the test; relict flanges of earlier chambers often visible along the periphery.

Entries in the Catalog of original descriptions: Laeviheterohelix turgida

Geological Range:
Last occurrence (top): within G. elevata zone (79.20-84.19Ma, top in Campanian stage). Data source: [copied from Chronos database]
First occurrence (base): within D. asymetrica zone (84.19-86.71Ma, base in Coniacian 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

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Laeviheterohelix turgida, synonyms included - Laeviheterohelix turgida;
  • space-time plot :: Samples map :: Parent: Laeviheterohelix

    Character matrix

    test outline:Subtriangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
    sp chamber shape:Inflatedcoiling axis:N/Aperiphery:N/Aaperture border:Thick flange
    umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:N/Aaccessory apertures:Relict
    spiral sutures:Strongly depressedumb depth:Shallowwall texture:Pore moundsshell porosity:Microperforate: <1µm
    umbilical or test sutures:Strongly depressedfinal-whorl chambers:2.0-2.0 N.B. These characters are used for advanced search. N/A - not applicable

    References:

    Nederbragt, A. J. (1991). Late Cretaceous biostratigraphy and development of Heterohelicidae (planktic foraminifera). Micropaleontology. 37: 329-372. gs


    logo

    Laeviheterohelix turgida compiled by the pforams@mikrotax project team viewed: 14-11-2019

    Taxon Search:
    Advanced Search

    Short stable page link: http://mikrotax.org/pforams/index.php?id=110307 Go to Archive.is to create a permanent copy of this page - citation notes



    Comments (0)

    No comments yet. Be the first!

    Add Comment

    * Required information
    1000
    Captcha Image
    Powered by Commentics