pforams@mikrotax - Planomalina

pforams@mikrotax - Planomalina pforams@mikrotax - Planomalina

Planomalina

Classification: pf_mesozoic -> Planomalinidae -> Planomalina
Sister taxa: Planomalina, Pseudoplanomalina

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

Taxonomy

Citation: Planomalina Loeblich and Tappan 1946

Rank: Genus

Type species: Planomalina apsidostroba Loeblich and Tappan, 1946 = Planulina buxtorfi Gandolfi, 1942

Taxonomic discussion: Although Robaszynski and Caron (1979, p. 43) state that the stratigraphic range is Upper Albian ("Vraconnian"), the type locality of P. apsidostroba (type species of the genus but a synonym of P. buxtorfi) was in the Main Street Limestone in Johnson Co., Texas, a formation containing the ammonite Plesioturrilites brazoensis (Roemer), whose first occurrence now is regarded as marking the Albian-Cenomanian boundary. P. buxtorfi also occurs in the underlying Paw Paw Formation of the Fort Worth region of Texas (that we also regard as lowest Cenomanian); furthermore it has been recorded (as P. almadenensis Cushman and Todd) in the Cenomanian of California, as well as in the upper Albian Weno and Georgetown Formations of central Texas.

Original description: Test free, planispiral, partially evolute, so that earlier coils may be seen on both sides of the biumbilicate test; chambers numerous; sutures may be limbate; wall calcareous, coarsely perforate; apertnuor peripheral, an arch at the base of the aptertural face of the last-formed chamber, with a distinct lip.

Entries in the Catalog of original descriptions: Planomalina

Distinguishing features:
Parent taxon (Planomalinidae): Test planispiral, biumbilicate, periphery carinate, sutures strongly arched; aperture a low equatorial opening.
This taxon: Test planispiral, partly evolute, biumbilicate, about eight to ten chambers in the final whorl, sutures broadly curved, thickened, elevated and nodose, peripheral outline lobulate, peripheral angle carinate; wall calcareous, finely perforate, radial in structure, ornamented by the thickened and nodose sutures and peripheral keel; aperture a basal equatorial arch with bordering lip, the opening extending to either side, where part of previous apertures and the bordering lip may remain exposed as relict apertures as the new chambers are added.

Geological Range:
Last occurrence (top): at top of Albian Stage (100% up, 100.5Ma, in Albian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Albian Stage (72% up, 104Ma, in Albian stage). Data source: Total of range 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: Planomalinidae

References:

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

Planomalina compiled by the pforams@mikrotax project team viewed: 31-3-2023

Taxon Search:

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AphiaID: 721410 Nomenclatural data on WoRMS
Short stables page link: https://mikrotax.org/pforams/index.php?id=110412 Go to Archive.is to create a permanent copy of this page - citation notes

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