pforams@mikrotax - Praegublerina pforams@mikrotax - Praegublerina

Praegublerina


Classification: pf_mesozoic -> Heterohelicidae -> Praegublerina
Sister taxa: Heterohelix, Spiroplecta ⟩⟨ Braunella, Hendersonites, Huberella, Laeviheterohelix, Planoheterohelix, Protoheterohelix, Pseudoguembelina, Pseudotextularia ⟩⟨ Planoglobulina, Ventilabrella, Gublerina, Praegublerina, Sigalia, Racemiguembelina ⟩⟨ Lunatriella, Rectoguembelina, Zeauvigerina
Daughter taxa (time control age-window is: 0-800Ma)
Praegublerina acuta

Praegublerina pseudotessera
From Georgescu, Saupe, and Huber, 2009: "Praegublerina pseudotessera differs from Heterohelix planata by having (i) divergent rows of biserial chambers resulting in the development of a central nonseptate area in the adult part of the test, (ii) reniform chambers in the adult part of the test, (iii) larger periapertural flanges and (iv) coarser costae. It differs from Gublerina rajagopalani in that it has an entirely finely costate test and lacks pseudokeels on the lateral sides of the test. Praegublerina pseudotessera differs from Laeviheterohelix pulchra (Brotzen 1936) in (i) being completely costate rather than ornamented with pore mounds and (ii) in having a central nonseptate area between the two rows of diverging chambers in the adult portion of the test."
Praegublerina robusta

Praegublerina sp.
Specimens which cannot be assigned to established species

Taxonomy

Citation: Praegublerina Georgescu, Saupe&Huber 2009
taxonomic rank: Genus
Type species: Gublerina acuta robusta de Klasz 1953
Taxonomic discussion: Praegublerina nov. gen. differs from Heterohelix in having (i) a central nonseptate area between the two rows of diverging chambers, (ii) a chamber proliferation stage in the evolved taxa (e.g., P. acuta, P. robusta) and (iii) coarser costae than in H. planata, its ancestral species, and reticulate ornamentation, the latter being present either on distinct parts of the test or all over the test surface. Praegublerina differs from Gublerina in having (i) a multiserial stage with chamber sets increasing their number by one chamber at a time rather than three chambers with each successive chamber set, (ii) finer costae (when present) and reticulate ornamentation without smooth sutures and unornamented portions and (iii) transverse biaperturate walls between the chambers of the multiserial chamber stage (text-figure 4).

Original description: Diagnosis. Tests are biserial throughout or with a multiserial chamber stage in the adult portion; a chamber proliferation stage follows the biaperturate progressive chamber; maximum of three multiserial chamber sets that gradually increase their number by one; test ornamentation costate or reticulate throughout, or a combination of the two kinds.

Description. Test is biserial throughout in earlier species of the lineage with chamber proliferation in the adult stage in the more highly evolved forms. Test outline is subtriangular to flaring due to the addition of chambers in the proliferation stage. The earlier biserial stage presents a central nonseptate area bounded by two rows of divergent chambers. The chamber proliferation stage initiates with the progressive chamber, which is the first biaperturate chamber of the test, and is followed by up to three multiserial chamber sets, the latter increasing the chamber number by one as new sets are added (i.e., two, then three, then four additional chambers in successive multiserial chamber sets). The test periphery is broadly rounded without peripheral structures. The aperture is single at the base of the last-formed chamber in the biserial stage and multiple due to the presence of both monoand biaperturate chambers in the multiserial stage. Apertures are bordered by wide flanges that are occasionally rimmed. Transverse biaperturate walls can be developed between the chambers in the multiserial portion of the test. Chamber surface is costate or reticulate or a combination of the two. The reticulate ornamentation occurs later in the genus history, being derived from costate forms. Test wall is calcareous, hyaline, and microperforate to finely perforate.

Entries in the Catalog of original descriptions: Praegublerina

Distinguishing features:
Parent taxon (Heterohelicidae): Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
This taxon: Similar to Gublerina but: 1. chamber sets increasing by one chamber at a time rather than three; 2. finer costae; 3. transverse biaperturate walls in multiserial part.


Morphology:
Tests are biserial throughout or with a multiserial chamber stage in the adult portion; a chamber proliferation stage follows the biaperturate progressive chamber; maximum of three multiserial chamber sets that gradually increase their number by one; test ornamentation costate or reticulate throughout, or a combination of the two kinds.

Geological Range:
Last occurrence (top): at top of P. hariaensis zone (100% up, 66.4Ma, in Maastrichtian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within G. elevata zone (79.33-83.65Ma, base in Campanian stage). Data source: Total of ranges of species in this database

Plot of range and occurrence data:

References:

Georgescu, M. D., Saupe, E. E. & Huber, B. T. (2009). Morphometric and stratophenetic basis for phylogeny and taxonomy in Late Cretaceous gublerinid planktonic foraminifera. Micropaleontology. 54(5): 397-424. gs


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Praegublerina compiled by the pforams@mikrotax project team viewed: 14-12-2024

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