Corannulus


Classification: ntax_cenozoic -> Holococcoliths -> fossil holococcoliths -> Corannulus
Sister taxa: Clathrolithus, Corannulus, Daktylethra, Holodiscolithus, Lanternithus, Multipartis, Octolithus, Orthozygus, Quadrilateris, Semihololithus, Varolia, Youngilithus, Zygrhablithus, Unidentified fossil holococcoliths

Daughter taxa (time control age-window is: 0-800Ma)
Corannulus germanicus
Ring-shaped, broadly elliptical, non-birefringent holococcolith with multiple (~7-11) thorn-like projections around the outer edge. Morphology clearest in phase constrast illumination where outer rim shows high relief.
Corannulus horridulus
Small to medium sized elliptical coccolith with a broad rim and narrow vacant central area. The rim is thick and ragged in overall appearance.
Corannulus sp.
Specimens which cannot be assigned to any established species

Taxonomy:

Citation: Corannulus Stradner, 1962
Rank: Genus
Type species: Corannulus germanicus Stradner, 1962
Synonyms: Diademopetra Hay et al 1966
Variants: Guttilithion Stradner 1962 - seems to be a less regular variant

Distinguishing features: Discoidal holococcoliths with large central openings and marginal perforations or indentations; non-birefringent in plan view.

Farinacci & Howe catalog pages: Corannulus * , Diademopetra * , Guttilithion *

Search data:
TagsLITHS: holococcolith, asymmetric, CA: vacant, CROSS-POLARS: 1ou, V-prominent,
MetricsLith size: 4->10µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in lower part of Rupelian Stage (17% up, 32.9Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Ypresian Stage (0% up, 56Ma, in Ypresian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Hay, W. W., Mohler, H. P. & Wade, M. E. (1966). Calcareous nannofossils from Nal'chik (northwest Caucasus). Eclogae Geologicae Helvetiae. 59: 379-399. gs V O

Stradner, H. (1962). Über neue und wenig bekannte Nannofossilien aus Kreide und Alttertiär. Verhandlungen der Geologischen Bundesanstalt (Wien). 2: 363-377. gs V O


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Corannulus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 9-3-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=345 Go to Archive.is to create a permanent copy of this page - citation notes



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