Taxonomy
Original description: Test 1½-2 times as long as broad, rather rapidly taperipg, initial end often acute with a slight point, somewhat compressed, earlier portion with the periphery slightly keeled, later portion: slightly idented; chambers slightly inflated, mostly broader than high, last ones with the inner portion reduced in height; sutures in the early portion slightly limbate and little if at all depressed, later depressed and slightly curved; wall ornamented throughout with fine longitudinal costae, becoming somewhat·curved and nearly parallel to the periphery in the later part; aperture semi circular, with a slightly thickened lip.
Entries in the Catalog of original descriptions: Guembelina costulata
Character matrix
test outline: | Subtriangular | chamber arrangement: | Biserial | edge view: | Compressed | aperture: | Interiomarginal |
sp chamber shape: | Subrectangular | coiling axis: | N/A | periphery: | N/A | aperture border: | Thin flange |
umb chbr shape: | Subrectangular | umbilicus: | N/A | periph margin shape: | Moderately rounded | accessory apertures: | Sutural |
spiral sutures: | Moderately depressed | umb depth: | N/A | wall texture: | Coarsely costate | shell porosity: | Microperforate: <1µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 2-2 | N.B. These characters are used for advanced search. N/A - not applicable |
Geological Range:
Last occurrence (top): within A. mayaroensis zone (67.64-69.27Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within G. elevata zone (79.33-83.65Ma, base in Campanian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Cushman, J. A. (1938). Cretaceous species of Guembelina and related genera. Contributions from the Cushman Laboratory for Foraminiferal Research. 14: 2-28. gs Nederbragt, A. J. (1991). Late Cretaceous biostratigraphy and development of Heterohelicidae (planktic foraminifera). Micropaleontology. 37: 329-372. gs Pessagno, E. A. (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana. 5: 245-445. gs O Smith, C. C. & Pessagno, E. A. (1973). Planktonic foraminifera and stratigraphy of the Corsicana formation (Maestrichtian) North-central Texas. Cushman Foundation for Foraminiferal Research, Special Publication. 12: 1-67. gs OReferences:
Pseudoguembelina costulata compiled by the pforams@mikrotax project team viewed: 14-12-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=110451 Go to Archive.is to create a permanent copy of this page - citation notes |
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