Classification: pf_mesozoic -> Heterohelicidae -> Spiroplecta
Sister taxa: Braunella, Gublerina, Hendersonites, Heterohelix, Huberella, Laeviheterohelix, Lunatriella, Planoglobulina, Planoheterohelix, Praegublerina, Protoheterohelix, Pseudoguembelina, Pseudotextularia, Racemiguembelina, Rectoguembelina, Sigalia, Spiroplecta, Ventilabrella, Zeauvigerina,
Citation: Spiroplecta Ehrenberg 1844Rank: GenusBasionym: Spiroplecta americanaType species: Spiroplecta americana Ehrenberg, 1844Taxonomic discussion: With redescription by Frerichs and Gaskill (1978, *1182, p. 143) of Textilaria americana (type species of Heterohelix) as having prominently subtriangular to laterally apiculate chambers, the distinction between Heterohelix and the globular-chambered Spiroplecta appears sufficient for recognition of both. Ehrenberg's figure (1854, *1068, pl. 32 II, fig. 25) was designated by Cushman as the "genotype" of Spiroplecta. This specimen was later stated to be the lectotype of the species (Loeblich, 1951, *1875, p. 108). When regarded as congeneric with Heterohelix, Spiroplecta americana becomes a secondary junior homonym of Textilaria americana Ehrenberg, 1843 (the type species of Heterohelix) and is then correctly known as Heterohelix navarroensis Loeblich, 1951. However, if both genera are recognized as distinct, as they are herein, they are no longer secondary homonyms and the present type species is correctly cited as Spiroplecta americana.
Original description: Spiroplecta:
Entries in the Catalog of original descriptions:
Short diagnosis: Test with early chambers in a planispiral coil, at least in the microspheric stage, later biserial, chambers globular and inflated, sutures depressed; wall calcareous, perforate, commonly ornamented with fine longitudinal striae; aperture a symmetrical arch at the base of the final chamber.
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 Campanian Stage (72.05-83.64Ma, base in Campanian stage). Data source: Total of range of species in this database
Plot of occurrence data:
NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.
- 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
- Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Heterohelicidae
Loeblich, A.R., Jr. & Tappan, H., (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York, 1059 pp.
Spiroplecta compiled by the pforams@mikrotax project team viewed: 25-11-2017
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