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Planomalina


Classification: pf_mesozoic -> Planomalinidae -> Planomalina
Sister taxa: Planomalina, Pseudoplanomalina,
Daughter taxa (blue => in age window 0-300Ma)


Specimens which cannot be assigned to established species

Taxonomy

Citation: Planomalina Loeblich and Tappan 1946
Rank: Genus
Basionym: Planomalina apsidostroba = Planulina buxtorfi
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.

Type images:

Original description: Planomalina Loeblich & Tappan, 1946:

Entries in the Catalog of original descriptions: Planomalina;

Short diagnosis: 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): within Albian Stage (100.50-112.95Ma, top in Albian stage). Data source: Total of range of species in this database
First occurrence (base): within Albian Stage (100.50-112.95Ma, base in Albian 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.

References:

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


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Planomalina compiled by the pforams@mikrotax project team viewed: 13-12-2017

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