pforams@mikrotax - Spiroplecta

pforams@mikrotax - Spiroplecta pforams@mikrotax - Spiroplecta

Spiroplecta

Classification: pf_mesozoic -> Heterohelicidae -> Spiroplecta
Sister taxa: Heterohelix, Spiroplecta ⟩⟨ Braunella, Hendersonites, Huberella, Laeviheterohelix, Planoheterohelix, Protoheterohelix, Pseudoguembelina, Pseudotextularia ⟩⟨ Planoglobulina, Ventilabrella, Gublerina, Praegublerina, Sigalia, Racemiguembelina ⟩⟨ Lunatriella, Rectoguembelina, Zeauvigerina

Daughter taxa (time control age-window is: 0-800Ma)
			Spiroplecta americana
			Spiroplecta sp. Specimens which cannot be assigned to established species

Taxonomy

Citation: Spiroplecta Ehrenberg 1844

taxonomic rank: Genus

Type species: Spiroplecta americana Ehrenberg, 1844

Taxonomic discussion: "With redescription by Frerichs and Gaskill (1978, 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, 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, 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 the two 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." [from Chronos, probably quoted from Georgescu & Huber 2009]

Original description: XI. SPIROPLECTAE nomine appelavi (Spiral-Zöpfchen). Quod Clavulina Nodosariis, Sagrina Textulariis, est id Spiroplecta est Rotaliis. In statu juniore cellulae spiralem ordinem sequuntur in adulto alteroum.
Spiroplecta americana Textilariae americanae affinis est, quam nuper indicavi. Spirulina e Rotaliarum forma in Nodosariae. Spiroplecta in Textilariae formam abit.

Approximate translation: (JRY 2019)
Spiroplecta - new name (spiral-pigtail). As Clavulina in the Nodosarids, Sagrina in the Textulrarids so is Spiroplecta in the Rotalids. The juvenile chambers are spirally arranged follwing which in the adult they alternate.
Spiroplecta americana has affinty to Textilaria americana, as previously mentioned. Spirulina is in the form out of the Rotaliarum Nodosariae. Spiroplecta in the form Textilariae zero.

Entries in the Catalog of original descriptions: Spiroplecta

Distinguishing features:
Parent taxon (Heterohelicidae): Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
This taxon: Initially planispiral then biserial, chambers globular, aperture symmetrical, wall texture costate

Morphology:

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.

Geological Range:
Last occurrence (top): at top of P. hariaensis zone (100% up, 66.4Ma, in Maastrichtian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within R. calcarata zone (75.06-75.91Ma, base in Campanian stage). Data source: Total of ranges of species in this 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
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Heterohelicidae

References:

Ehrenberg, C. G. (1843b). Verbreitung und Einfluss des mikroscopischen Lebens in Süd- und Nord Amerika. Bericht uber die zu Bekanntmachung geeigneten Verhandlungen der Koniglichen Preussische Akademie der Wissenschaften zu Berlin. 1841: 291-446. gs

Ehrenberg, C. G. (1854). Mikrogeologie: Das Erden und Felsen schaffende Wirken des unsichtbar kleinen selbständigen Lebens auf der Erde. Leopold Voss, Leipzig. 1-374. gs

Frerichs, W. E. & Gaskill, C. H. (1978). Textilaria americana Ehrenberg: Type species of Heterohelix. Journal of Foraminiferal Research. 8(2): 143-146. gs

Georgescu, M. D. & Huber, B. T. (2009). Early evolution of the Cretaceous serial planktic foraminifera (late Albian-Cenomanian). Journal of Foraminiferal Research. 39: 335-360. gs

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

Loeblich, A. R. (1951). Coiling in the Heterohelicidae. Contributions from the Cushman Foundation for Foraminiferal Research. 2: 106-110. gs

Spiroplecta compiled by the pforams@mikrotax project team viewed: 16-10-2024

Taxon Search:

Advanced Search

Short stable page link: https://mikrotax.org/pforams/index.php?id=110535 Go to Archive.is to create a permanent copy of this page - citation notes