pforams@mikrotax - Laeviheterohelix turgida

pforams@mikrotax - Laeviheterohelix turgida pforams@mikrotax - Laeviheterohelix turgida

Laeviheterohelix turgida

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

ODP Leg 174-172.JPG

Taxonomy

Citation: Laeviheterohelix turgida Nederbragt 1991

Rank: Species

Basionym: Laeviheterohelix turgida

Taxonomic discussion: Laeviheterohelix turgida resembles its probable ancestor L. pulchra in its large apertural flanges and reniform chambers. It differs from L. pulchra in its deeper and more inflated test and its subacute periphery. The two species can be found in a single sample, but they form distinct populations without morphologic transitions. Laeviheterohelix turgida differs from L. dentata in its deeper test and larger apertural flanges.

Probably smooth forms of L. turgida could be found, just as in L. pulchra. However, all specimens encountered in this study have pore mounds (most of the samples from the El Kef section) or are recrystallized to the extent that the wall structure cannot be observed (some samples from El Kef and all of the Site 356 specimens). [copied from Chronos database]

Type images:

holotype: L. turgida

Original description: Test biserial throughout, wall microperforate, with pore mounds. Chambers inflated, subglobular in the juvenile, later becoming slightly reniform. Sides of test gently tapering; sutures deeply depressed. Individual chambers with greatest depth near the median suture, pinched near the periphery, to give a subacute periphery. Aperture bordered by elongate flanges, which extend to the opposite edge of the test; relict flanges of earlier chambers often visible along the periphery.

Entries in the Catalog of original descriptions: Laeviheterohelix turgida

Character matrix
test outline: Subtriangular chamber arrangement: Biserial edge view: Compressed aperture: Interiomarginal
sp chamber shape: Inflated coiling axis: N/A periphery: N/A aperture border: Thick flange
umb chbr shape: Inflated umbilicus: Wide periph margin shape: N/A accessory apertures: Relict
spiral sutures: Strongly depressed umb depth: Shallow wall texture: Pore mounds shell porosity: Microperforate: <1µm
umbilical or test sutures: Strongly depressed final-whorl chambers: 2.0-2.0 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 G. elevata zone (79.20-84.19Ma, top in Campanian stage). Data source: [copied from Chronos database]
First occurrence (base): within D. asymetrica zone (84.19-86.71Ma, base in Coniacian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Laeviheterohelix turgida, synonyms included - Laeviheterohelix turgida;
See also space-time plot :: Samples map :: Parent: Laeviheterohelix

References:

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

Laeviheterohelix turgida compiled by the pforams@mikrotax project team viewed: 5-6-2023

Taxon Search:

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AphiaID: 1030507 Nomenclatural data on WoRMS
Short stables page link: https://mikrotax.org/pforams/index.php?id=110307 Go to Archive.is to create a permanent copy of this page - citation notes

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test outline:	Subtriangular	chamber arrangement:	Biserial	edge view:	Compressed	aperture:	Interiomarginal
sp chamber shape:	Inflated	coiling axis:	N/A	periphery:	N/A	aperture border:	Thick flange
umb chbr shape:	Inflated	umbilicus:	Wide	periph margin shape:	N/A	accessory apertures:	Relict
spiral sutures:	Strongly depressed	umb depth:	Shallow	wall texture:	Pore mounds	shell porosity:	Microperforate: <1µm
umbilical or test sutures:	Strongly depressed	final-whorl chambers:	2.0-2.0	N.B. These characters are used for advanced search. N/A - not applicable