Biscutum asymmetricum


Classification: Mesozoic -> Podorhabdales -> Biscutaceae -> Biscutum -> Biscutum asymmetricum
Sister taxa: B. arrogans, B. asymmetricum, B. boletum, B. constans, B. coronum, B. davyi, B. dekaenelii, B. depravatus, B. dissimilis, B. dorsetensis, B. dubium, B. ellipticum, B. erismatum, B. gaultensis, B. grande, B. hattneri, B. intermedium, B. magnum, B. melaniae, B. notaculum, B. planum, B. profundum, B. thurowii, B. virginica, B. zulloii, B. sp.,

Distinguishing features: Asymmetric species, with strongly asymmetric proximal shield and weakly asymmetric distal shield.


Taxonomy:

Citation: Biscutum asymmetricum Perch-Nielsen 1968
Rank: Species
Synonyms:
Notes & discussion: B. asymmetricum has been considered a synonym of B. constans by for example Verbeek (1977) and it is very similar in distal view, in proximal view, however, the asymettry is clear;
The species seems to have been described independantly by Perch-Nielsen (1968), from the Maastrichtian of Denmark and by Bukry (1969) from the Santonian of Texas with both authors using the same name. The description and illustration of Bukry (1969) is better than that of Perch-Nielsen (1968) but they both appear to be illustrating the same species

Farinacci & Howe catalog pages: Biscutum asymmetricum *

Distinguishing features: Asymmetric species, with strongly asymmetric proximal shield and weakly asymmetric distal shield.


Morphology remarks: Coccospheres often somwhat elongate. No spine formed.  

Geological Range:
Last occurrence (top): within (-Ma, top in "Holocene" stage). Data source:
First occurrence (base): within (-Ma, base in stage). Data source:

Plot of occurrence data:

  • (NB There is no histogram as there are no occurrence records for the taxon in the Neptune database) Parent: Biscutum

    References:

    Bukry, D. (1969). Upper Cretaceous coccoliths from Texas and Europe. The University of Kansas Paleontological Contributions. Article 51 (Protista 2): 1-79. gs

    Bukry, D. (1970). Biscutum kennedyi, nom. nov. pro Biscutum asymmetricum Bukry 1969, non Perch-Nielsen 1968 (Plantae, Coccolithophyceae). Journal of Paleontology. 44(1): 167-. gs

    Perch-Nielsen, K. (1968c). Der Feinbau und die Klassifikation der Coccolithen aus dem Maastrichtien von Danemark. Biologiske Skrifter. Kongelige Danske Videnskabernes Selskab. 16: 1-96. gs


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    Biscutum asymmetricum compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-8-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10068 Go to Archive.is to create a permanent copy of this page - citation notes



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