Nannotax3 - ntax_mesozoic - Cylindralithus Nannotax3 - ntax_mesozoic - Cylindralithus

Cylindralithus


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

Distinguishing features:
Parent taxon (Stephanolithiaceae): Murolith (protolith type) coccoliths with rims of non-imbricate V-units and weakly-developed, or vestigial, proximal/inner-cycles (R-units), with central-areas spanned by one to numerous bars. 
This taxon: Circular or sub-circular with high, sculpted, wall; central-area vacant or with cross bars.


Daughter taxa (time control age-window is: 0-800Ma)
Cylindralithus biarcus
Cylindralithus with diagonal central-area cross-bars defining two large and two small pores
Cylindralithus coronatus
Circular or broadly elliptical; central area with broad symmetric crossbars, serrated outline
Cylindralithus sculptus
Circular; open central area; parallel sided
Cylindralithus serratus
Circular; central area open; serrated outer margin
Possible Watznaueriaceae
Cylindralithus duplex
Circular; open central area, both distal shield and proximal shield elevated
Cylindralithus oweinae
Circular; open central area, both distal shield and proximal shield elevated - thick walled
Cylindralithus flat-top
Circular with flat surface without flange, column slightly tapering with weakly imbricate elements
Anomalous species
Cylindralithus nieliae
Widest cycle elongate and constricted (figure of eight shape)
Cylindralithus sp.
Specimens not identified to species level

Taxonomy:

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

Farinacci & Howe catalog pages: Cylindralithus *

Distinguishing features:
Parent taxon (Stephanolithiaceae): Murolith (protolith type) coccoliths with rims of non-imbricate V-units and weakly-developed, or vestigial, proximal/inner-cycles (R-units), with central-areas spanned by one to numerous bars. 
This taxon: Circular or sub-circular with high, sculpted, wall; central-area vacant or with cross bars.


Morphology:

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.

Search data:
LITHS: murolith, circular, CA: cross-axial, ca_disjunct, vacant, diagonal cross,
Lith size: 4->9µm;
Data source notes: size range of included species
The morphological data given here can be used on the advanced search page. See also these notes

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

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Albian Stage (100.50-113.20Ma, base in Albian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Bown, P. R. & Young, J. R. (1997). Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 21-36. gs

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

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


nannotaxlogo400px

Cylindralithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-6-2024

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10353 Go to Archive.is to create a permanent copy of this page - citation notes
nannotaxlogo400px

Nannotax is being sponsored through 2024 by Woodside Energy and Shell USA


Add Comment

* Required information
Captcha Image
Powered by Commentics

Comments

No comments yet. Be the first!