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Pseudoguembelina kempensis


Classification: pf_mesozoic -> Heterohelicidae -> Pseudoguembelina -> Pseudoguembelina kempensis
Sister taxa: P. costellifera, P. costulata, P. excolata, P. hariaensis, P. kempensis, P. palpebra, P. semicostata, P. sp.

Taxonomy

Citation: Pseudoguembelina kempensis Esker 1968
Rank: Species
Basionym: Pseudoguembelina kempensis

Type images:

Original description: Test plano-biserial or biserial, consisting of 7-12large chambers, increasing rapidly in size, and mayhave a small pointed early part consisting of about 7 additional chambers. The small early chambersmay be coiled initially (text fig. 4). The small early chambers are not inflated and the sutures are nearlyflush with the chamber surface. The surface ispunctate with the alignment of the pores, particu- larly towards the outer margin, sometimes suggest- ing faint striae (text fig. 3). The microspheric forms tend to lack spines and are not as thick. The third pair of chambers is the most strongly inflated, after which later chambers tend to be less inflatedand, finally, somewhat compressed. The last cham-ber may be very elongate and may extend com- pletely over the preceding two chambers. On the megalospheric forms, the first few large chambersusually have short thick spines that may tend to merge to form a sort of ridge. These tend to im- part a knobby appearance to the chamber (text fig. 2). Text figs. 3 and 4 show the extremes in the degree to which the test is pointed. The sutures aredeeply depressed between the large chambers. A rather thick conspicuous carina is present. The primary aperture is a large lunate arch in all cham-bers except the last one (text fig. 5). With the completion of the final chamber, the primary aperture is reduced to a narrow slit which tends strongly to become or actually forms three separate aper-tures (text fig. 2). In addition to the primary aper- ture or apertures, there are usually at least three pairs of narrow slit-like accessory apertures withprominent flaps.

Entries in the Catalog of original descriptions: Pseudoguembelina kempensis

Geological Range:
Last occurrence (top): within A. mayaroensis zone (67.30-69.18Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within G. gansseri zone (71.75-72.97Ma, base in Campanian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:

Character matrix

test outline:Subtriangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:Subrectangularcoiling axis:N/Aperiphery:Single keelaperture border:Thin flange
umb chbr shape:Subrectangularumbilicus:N/Aperiph margin shape:Subangularaccessory apertures:Sutural
spiral sutures:Moderately depressedumb depth:N/Awall texture:Coarsely costateshell porosity:-
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:

Esker, G. C. (1968a). A new species of Pseudoguembelina from the Upper Cretaceous of Texas. Contributions from the Cushman Foundation for Foraminiferal Research. 19(4): 168-169. gs V O

Nederbragt, A. J. (1989b). Maastrichtian Heterohelicidae (Planktonic Foraminifera) from the North West Atlantic. Journal of Micropalaeontology. 8(2): 183-206. gs V O

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


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Pseudoguembelina kempensis compiled by the pforams@mikrotax project team viewed: 21-4-2021

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Short stable page link: https://mikrotax.org/pforams/index.php?id=110454 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (1)

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Le Coze

Ref.: "Contribution from the Cushman Foundation for foraminiferal research" not "Contributions from the Cushman Laboratory for Foraminiferal Research"

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Jeremy Young (UK)

good point - I'll check the other Cushman references for this (the changeover was in 1950).

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