Neocrepidolithus


Classification: Coccolithophores -> Mesozoic Survivors -> Chiastozygaceae -> Neocrepidolithus
Sister taxa: Jakubowskia, Neocrepidolithus, Staurolithites, Zeugrhabdotus,

Distinguishing features: Murolith (loxolith) coccoliths with broad, high rim and narrow or closed central-area, which may be spanned by bars.


Daughter taxa: (blue => in age window 0-800Ma)
Unicyclic Neocrepidolithus with closed central area.
Neocrepidolithus with narrow central area filled with an axial cross. Clearly bicyclic in LM.
Bicyclic Neocrepidolithus with closed central area.
Neocrepidolithus with broad rim and narrow to closed central area. No obvious central structures and unicyclic in LM.
Medium to large Neocrepidolithus with a broad rim, unicyclic in XPL, and a narrow, vacant central area. The central area width is variable, usually around the same width as the rim, but may be narrower or closed.
Neocrepidolithus with bicyclic LM image and narrow to closed central area.
Specimens which cannot be assigned to any established species

Taxonomy:

Citation: Neocrepidolithus Romein, 1979
Rank: Genus
Type species: Crepidolithus neocrassus Perch-Nielsen, 1968
Notes & discussion: Includes a number of species that are very similar and may represent synonyms (e.g. N. coheni, N. neocrassus and N. fossus).

Farinacci & Howe catalog pages: Neocrepidolithus *

Distinguishing features: Murolith (loxolith) coccoliths with broad, high rim and narrow or closed central-area, which may be spanned by bars.


Size: Most species are 4-7 µm long (ie. medium size) the prime exception is N. grandiculus which is much larger (7-13.5 µm)

Search data:
TagsLITHS: murolith, elliptical, RIM: outer wall cw-imbricate, CA: Placoliths: closed,
CSPH: not known, V-UNITS: outer-rim, R-UNITS: inner-rim,
MetricsLith size: 4->13.5┬Ám;
Sources:
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 Ypresian Stage (28% up, 53.7Ma, in Ypresian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Turonian Stage (0% up, 93.9Ma, in Turonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Burnett, J.A., (1998). Upper Cretaceous. In: Bown, P.R. (Editor), Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publications Series. Chapman & Hall, London, pp. 132-199.GS

Romein, A.J.T., (1979). Lineages in Early Paleogene calcareous nannoplankton. Utrecht Micropaleontological Bulletins, 22: 231.GS


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Neocrepidolithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-3-2019

Taxon Search:
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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=930 Go to Archive.is to create a permanent copy of this page - citation notes



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