Classification: pf_mesozoic -> Heterohelicidae -> Heterohelix
Sister taxa: Braunella, Gublerina, Hendersonites, Heterohelix, Huberella, Laeviheterohelix, Lunatriella, Planoglobulina, Planoheterohelix, Praegublerina, Protoheterohelix, Pseudoguembelina, Pseudotextularia, Racemiguembelina, Rectoguembelina, Sigalia, Spiroplecta, Ventilabrella, Zeauvigerina,
Daughter taxa: (blue => in age window 0-800Ma)

Specimens which cannot be assigned to established species


Citation: Heterohelix Ehrenberg 1843
Rank: Genus
Basionym: Textilaria americana
Type species: Textilaria americana Ehrenberg, 1843
Taxonomic discussion: Heterohelix appears to be transitional between the globular chambered Spiroplecta and Lunatriella whose chambers are laterally much elongated or tubulospinate. As noted by Frerichs and Gaskill (1978, *1182, p. 143), the type species of Heterohelix is Textilaria americana Ehrenberg, 1843 (*1059) by original monotypy (hence Cushman's, 1927, *746, p. 190, designation of Spiroplecta americana as the type of Heterohelix is invalid). Textilaria americana was first illustrated by Ehrenberg (1854, *1068, pl. 32 I, fig. 4a), and similar specimens were illustrated by Frerichs and Gaskill. The latter authors regarded Ehrenberg's pl. 32 I, figs. 13, 14 of Spiroplecta americana to be the microspheric generation of Heterohelix americana.

Original description: Cellulae primae nonnullis spirales. Tales formae forsan proprio generi addicendae sunt: Heterohelix.

Approximate translation (by JRY 2019 - with assistance from google translate)
Sometimes the first chambers are spirally arranged. These forms can perhaps be assigned their own genus: Heterohelix.
N.B. This brief description appears after the description of Textilaria americana and is used to distinguish this form from similar biserial forams without the initial spiral portion. 

Entries in the Catalog of original descriptions: Heterohelix

Distinguishing features: Test with early chambers in a tiny planispiral coil, at least in the microspheric generation, later with biserially arranged inflated to globular chambers, final one to two pairs of chambers subtriangular in outline with a short blunt spine at the outer angle of the chamber, sutures depressed; wall calcareous, perforate, ornamented with numerous fine longitudinal striae; aperture a high narrow arch at the base of the last chamber.

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): within Cenomanian Stage (93.90-100.50Ma, base in Cenomanian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous


Ehrenberg, C. G. (1843b). Verbreitung und Einfluss des mikroscopischen Lebens in Süd- und Nord Amerika. Bericht k. preuss. Akad. Wiss. Berlin. 1841: 291-446. gs

Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gs


Heterohelix compiled by the pforams@mikrotax project team viewed: 18-9-2019

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Short stable page link: http://mikrotax.org/pforams/index.php?id=110283 Go to Archive.is to create a permanent copy of this page - citation notes

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