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Praegublerina acuta


Classification: pf_mesozoic -> Heterohelicidae -> Praegublerina -> Praegublerina acuta
Sister taxa: P. acuta, P. sp.,

Taxonomy

Citation: Praegublerina acuta (De Klasz, 1953)
Rank: Species
Basionym: Gublerina acuta
Synonyms: Gublerina hedbergi

Type images:

Original description: Diagnosis : A Gublerina with the following peculiarities: test relatively small, the initial chambers are increasing slowly; they are separated from each other by distinctly visible depressed sutures and not covered by rugosities like those of genotype G. cuvillieri.

Description : The test consists of two divergent rows of more or less globular chambers connected with each other by a calcareous lamella. The latter also contains a varying number of irregularly dispersed, often partly reniform, chambers filling almost the whole space between the two lateral rows of chambers of some of the specimens. The chambers of the lateral divergent rows are separated from each other by depressed sutures. Their size is generally increasing from the first to the last, although this increase in size is not always regular. The size of the initial chambers is increasing more slowly than of these ones of G. cuvillieri. The last chambers are often elongating a little towards the centre of the test. The whole test is sometimes compressed in the vertical direction towards the symmetric plane of both divergent rows of chambers. The calcareous lamella, filling the space between these rows, occasionally encloses the upper end of the test and part of its flanks.

The aperture of the specimens found up to now could not be seen; it can be assumed however that it is at the inner basis of the last chamher like G. cuvillieri Kikoine.

Entries in the Catalog of original descriptions: Gublerina acuta, Gublerina hedbergi


Emended description: Georgescu, Saupe & Huber. 2009, p.408-409: "The test has a subtriangular outline and is biserial in the early stage and multiserial when adult. Chambers of the biserial stage are rounded, subrectangular to reniform. There is a gradual tilting of the chambers with respect to the test growth axis. The test is compressed with the two sides of the test being quasi-parallel in edge view. Sutures in the biserial part of the test are depressed, straight and oblique to the test axis of growth and curved in the adult stage. The aperture in the earlier biserial chambers has a medium high arch at the base of the last formed chamber; it is bordered by long, wide periapertural flaps that are attached to the previous chamber. The periapertural flanges in the multiserial stage may be gently folded. The two rows of alternating chambers are divergent resulting in the development of a central nonseptate area. The early biserial stage is followed by the progressive chamber, which is subglobose in outline. The multiserial stage is poorly developed and consists of a single set of two elongate chambers beyond the progressive chamber. No transverse walls are present in the multiserial stage. The test is ornamented with five quasi-longitudinal bands of costae or reticulations. Two finely costate bands are developed at the test periphery with costae thickness between 3.0 and 3.4 microns. Pores are present in the spaces between the costae; their diameter ranges between 0.6 and 0.8 microns. The ornamentation over the chambers is incipiently reticulate with pore sizes ranging between 2.0 and 4.9 microns. The fifth band is centrally located over the central non-septate area and is finely costate with pores between 0.6 and 0.7 microns." [copied from Chronos database]

Geological Range:
Last occurrence (top): within P. hariaensis zone (66.39-67.30Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within R. calcarata zone (75.71-76.18Ma, base in Campanian 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: Praegublerina acuta, synonyms included - Gublerina acuta; Gublerina acuta robusta; Gublerina hedbergi; Gublerina robusta; Guembelina robusta;
  • space-time plot :: Samples map :: Parent: Praegublerina

    Character matrix

    test outline:Subtriangularchamber arrangement:Multiserialedge 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:Vermiculateshell porosity:Macroperforate: >2.5µm
    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:

    de Klasz, I. (1953b). On the Foraminiferal Genus Gublerina Kikoïne. Geologica Bavarica. 17: 245-251. gs

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


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    Praegublerina acuta 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=110440 Go to Archive.is to create a permanent copy of this page - citation notes



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