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Laeviheterohelix glabrans


Classification: pf_mesozoic -> Heterohelicidae -> Laeviheterohelix -> Laeviheterohelix glabrans
Sister taxa: L. dentata, L. flabelliformis, L. glabrans, L. pulchra, L. reniformis, L. turgida, L. sp.

Taxonomy

Citation: Laeviheterohelix glabrans (Cushman, 1938)
Rank: Species
Basionym: Guembelina glabrans
Synonyms:

Type images:

Original description: Test nearly twice as long as broad, tapering, throughout, much compressed, early portion with the periphery entire and slightly keeled, later moderatly indented; chambers in the microspheric form mostly slightly broader than high, in the megalospheric form with the later chambers with the height often as great or greater than the breadth, later ones more inflated but somewhat compressed throughout; sutures in the early portion slightly limbate, in the adult depressed; wall in the early portion coarsely punctulate, somewhat roughened, in the adult smooth and polished; aperture higher than broad, arched with a slight lip and flanges at the sides extending onto the preceding chamber.

Entries in the Catalog of original descriptions: Guembelina glabrans

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 (67.30-69.18Ma, 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:

Character matrix

test outline:Subtriangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:N/Acoiling axis:N/Aperiphery:N/Aaperture border:Thin flange
umb chbr shape:N/Aumbilicus:Wideperiph margin shape:N/Aaccessory apertures:None
spiral sutures:Moderately depressedumb depth:Shallowwall texture:Smoothshell porosity:Microperforate: <1µm
umbilical or test sutures:Weakly depressedfinal-whorl chambers:2.0-2.0 N.B. These characters are used for advanced search. N/A - not applicable

References:

Cushman, J. A. (1938). Cretaceous species of Guembelina and related genera. Contributions from the Cushman Laboratory for Foraminiferal Research. 14: 2-28. 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

Pessagno, E. A. (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana. 5: 245-445. gs V 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 V O


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Laeviheterohelix glabrans compiled by the pforams@mikrotax project team viewed: 7-3-2021

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Short stable page link: https://mikrotax.org/pforams/index.php?id=110303 Go to Archive.is to create a permanent copy of this page - citation notes



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