Cylindralithus


Classification: Mesozoic -> Stephanolithiales -> Stephanolithiaceae -> Cylindralithus
Sister taxa: Corollithion, Cylindralithus, Darwinilithus, Paralithella, Rectocorona, Rhombolithion, Rotelapillus, Stephanolithion, Stoverius, Stradnerlithus, Thurmannolithion, Truncatoscaphus,

Distinguishing features: Circular or sub-circular with high, sculpted, wall; central-area vacant or with cross bars.


Daughter taxa: (blue => in age window 0-800Ma)
Cylindralithus with diagonal central-area cross-bars defining two large and two small pores
Circular or broadly elliptical; central area with broad symmetric crossbars, serrated outline
Circular; open central are; parallel sided
Circular; central area open; serrated outer margin
Possible Watznaueriaceae
Circular; open central area, both distal shield and proximal shield elevated
Circular; open central area, both distal shield and proximal shield elevated - thick walled
Anomalous species
Widest cycle elongate and constricted (figure of eight shape)
Specimens not identified to species level

Taxonomy:

Citation: Cylindralithus Bramlette & Martini, 1964
Rank: Genus
Type species: Cylindralithus serratus Bramlette and Martini, 1964.

Farinacci & Howe catalog pages: Cylindralithus *

Distinguishing features: Circular or sub-circular with high, sculpted, wall; central-area vacant or with cross bars.


Morphology remarks: The earliest species, C. nudus, has watznaueriacean-like construction, with high shields (cf. Ansulasphaera). Unfortunately, the precise nature of the construction of the type species is difficult to discern from the LM holotype images.
In the electron microscope they are very reminiscent of Stephanolithids such as Rotelapillus but they show higher birefringence, suggesting that more of the coccolith is formed of R-units.

See also: Cylindralithus nudus - Watznauerician coccolith assigned to the genus;

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Maastrichtian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Albian Stage (0% up, 113Ma, in Albian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs

Bramlette, M. N. & Martini, E. (1964). The great change in calcareous nannoplankton fossils between the Maestrichtian and Danian. Micropaleontology. 10(2): 291-322. gs


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Cylindralithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-12-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10353 Go to Archive.is to create a permanent copy of this page - citation notes



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