Nannotax3 - ntax_mesozoic - Tubodiscaceae Nannotax3 - ntax_mesozoic - Tubodiscaceae

Tubodiscaceae


Classification: ntax_mesozoic -> Podorhabdales -> Tubodiscaceae
Sister taxa: Axopodorhabdaceae, Biscutaceae, Calyculaceae, Cretarhabdaceae, Mazaganellaceae, Prediscosphaeraceae, Tubodiscaceae

Distinguishing features:
Parent taxon (Podorhabdales): Placolith (or modified placolith) coccoliths showing little or no imbrication. Typically, V-units form distal shield, R-units form proximal shield.
This taxon: Elliptical placoliths composed of two narrow shields and a third, narrow, proximally-situated collar cycle that is variable in height. The central-area is broad and open; no central structures have yet been observed. The LM image is dark, although the collar cycle is brighter.


Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Manivitella
Tubodiscids with low proximal collar cycle and wide central-area.
Manivitella fibrosa
Manivitella pemmatoidea
Manivitella sp.

Tubodiscus
Tubodiscids with high and birefringent proximal collar cycle and wide central-area. Rim image is clearly bicyclic in XPL.
Tubodiscus bellii
Tubodiscus burnettiae
Tubodiscus frankiae
Tubodiscus jurapelagicus
Tubodiscus verenae
Tubodiscus sp.

Taxonomy:

Citation: Tubodiscaceae Bown & Rutledge, 1997 in Bown & Young, 1997
taxonomic rank: Family
Type species: Tubodiscus Thierstein, 1973.

Farinacci & Howe catalog pages: Tubodiscaceae *

Distinguishing features:
Parent taxon (Podorhabdales): Placolith (or modified placolith) coccoliths showing little or no imbrication. Typically, V-units form distal shield, R-units form proximal shield.
This taxon: Elliptical placoliths composed of two narrow shields and a third, narrow, proximally-situated collar cycle that is variable in height. The central-area is broad and open; no central structures have yet been observed. The LM image is dark, although the collar cycle is brighter.


Morphology:

Elliptical placoliths composed of two narrow shields and a third, narrow, proximally-situated collar cycle that is variable in height. The central-area is broad and open; no central structures have yet been observed. The LM image is dark, although the collar cycle is brighter.
Manivitella and Tubodiscus have similar rim structures but differ in the elevation of the proximal collar cycle, which is low in Manivitella and higher in Tubodiscus. The 'high-collared' forms appear distinct in the LM, as the increased height of the cycle produces high birefringence colours.

Search data:
: placolith,
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): 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 Late Tithonian Substage (143.10-145.00Ma, base in Tithonian 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

Thierstein, H. R. (1973). Lower cretaceous calcareous nannoplankton biostratigraphy. Abhandlungen der Geologischen Bundesanstalt. 29: 3-52. gs


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Tubodiscaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 5-12-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11271 Go to Archive.is to create a permanent copy of this page - citation notes
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