Nannotax3 - ntax_mesozoic - Anfractus variabilis <title>Nannotax3 - ntax_mesozoic - Anfractus variabilis

Anfractus variabilis


Classification: ntax_mesozoic -> Holococcoliths -> Rarer genera -> Anfractus -> Anfractus variabilis
Sister taxa: A. harrisonii, A. parvus, A. variabilis, A. youngii, A. sp.

Distinguishing features:
Parent taxon (Anfractus): Elliptical, cavate (and usually septate) holococcoliths, often bearing hollow spines. Distal surfaces may be perforate and there may be internal buttresses.
This taxon: Very small holococcolith with distal surface pierced by 8-10 pores.


Taxonomy:

Citation: Anfractus variabilis Medd, 1979
Rank: Species
Taxonomic discussion: Lambert (1987) documented great varibility in A. harrisonii and suggested A. variabilis should be considered a synonym/conspecific variant of it.

Farinacci & Howe catalog pages: A. variabilis *

Distinguishing features:
Parent taxon (Anfractus): Elliptical, cavate (and usually septate) holococcoliths, often bearing hollow spines. Distal surfaces may be perforate and there may be internal buttresses.
This taxon: Very small holococcolith with distal surface pierced by 8-10 pores.


Morphology:


Size:
Type length 1.8 microns.


Ecology & Biogeography


Biology & life-cycles

Phylogenetic relations

Search data:
:
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Callovian Stage (163.47-166.07Ma, top in Callovian stage). Data source: Medd, 1979
First occurrence (base): within Callovian Stage (163.47-166.07Ma, base in Callovian stage). Data source: Medd, 1979

Plot of occurrence data:

References:

Medd, A. W. (1979). The Upper Jurassic coccoliths from the Haddenham and Gamlingay boreholes (Cambridgeshire, England). Eclogae Geologicae Helvetiae. 72: 19-109. gs O


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Anfractus variabilis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-2-2023

Taxon Search:
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AphiaID: not found
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10021 Go to Archive.is to create a permanent copy of this page - citation notes



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