Taxonomy
Original description: Test with initial small-sized planispiral coil or more often biserial throughout. Chambers reniform increase rapidly in size as added. Sutures distinct, depressed and curced. Test compressed with subangular to angular periphery. No peripheral structures present. Test wall smooth, finely perforated. Scattered pustules can be recorded on the earlier formed chambers, the last formed ones being invariably smooth. Aperture a moderate high arch at the base of the apertural face is bordered by thin flanges.
Entries in the Catalog of original descriptions: Heterohelix dentata
Character matrix
test outline: | Subtriangular | chamber arrangement: | Biserial | edge view: | Compressed | aperture: | Interiomarginal |
sp chamber shape: | Petaloid | coiling axis: | N/A | periphery: | N/A | aperture border: | Thin flange |
umb chbr shape: | Petaloid | umbilicus: | N/A | periph margin shape: | Narrowly rounded | accessory apertures: | None |
spiral sutures: | Moderately depressed | umb depth: | N/A | wall texture: | Smooth | shell porosity: | - |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 2-2 | N.B. These characters are used for advanced search. N/A - not applicable |
Most likely ancestor: Laeviheterohelix pulchra - at confidence level 3 (out of 5). Data source: Nederbragt 1991.
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. havanensis zone (74.00-75.71Ma, base in Campanian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Nederbragt, A. J. (1991). Late Cretaceous biostratigraphy and development of Heterohelicidae (planktic foraminifera). Micropaleontology. 37: 329-372. gs Stenestad, E. (1968). Three new species of Heterohelix Ehrenberg from the upper Senonian of Denmark. Meddelelser fra Dansk Geologisk Forening. 18(1): 64-70. gsReferences:
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Laeviheterohelix dentata compiled by the pforams@mikrotax project team viewed: 9-2-2025
Short stable page link: https://mikrotax.org/pforams/index.php?id=110301 Go to Archive.is to create a permanent copy of this page - citation notes |
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