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.


Citation: Laeviheterohelix turgida Nederbragt 1991
taxonomic 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:

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:Subtriangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:Inflatedcoiling axis:N/Aperiphery:N/Aaperture border:Thick flange
umb chbr shape:Inflatedumbilicus:Wideperiph margin shape:N/Aaccessory apertures:Relict
spiral sutures:Strongly depressedumb depth:Shallowwall texture:Pore moundsshell porosity:Microperforate: <1┬Ám
umbilical or test sutures:Strongly depressedfinal-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 G. elevata zone (79.33-83.65Ma, top in Campanian stage). Data source: [copied from Chronos database]
First occurrence (base): within D. asymetrica zone (83.65-85.60Ma, base in Santonian 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


Laeviheterohelix turgida compiled by the pforams@mikrotax project team viewed: 16-6-2024

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