Tegumentum


Classification: Mesozoic -> Eiffellithales -> Eiffellithaceae -> Tegumentum
Sister taxa: Diloma, Eiffellithus, Helicolithus, Tegumentum,

Distinguishing features: Murolith (loxolith) coccoliths with a prominent inner rim cycle that is birefringent and conspicuous in cross-polarised light. This cycle is broader than the outer rim cycle. The central area is spanned by curving, diagonal cross-bars.


Daughter taxa: (blue => in age window 0-800Ma)
Medium-sized, murolith coccolith with a broad bicyclic rim, dominated by the thick, bright inner cycle, and a narrow, central area almost filled by short, broad, bright diagonal cross bars.
A species of Tegumentum with a narrow inner rim cycle and figure-of-eight cross-bars which can be resolved in a single plane of focus in the LM.IMAGE]
Tegumentum with diagonal cross bars that appear sigmoidally curved in XPL, with pointed terminations.
Specimens not identified to species level

Taxonomy:

Citation: Tegumentum Thierstein in Roth & Thierstein, 1972
Rank: Genus
Type species: Tegumentum stradneri Thierstein in Roth and Thierstein, 1972.

Farinacci & Howe catalog pages: Tegumentum *

Distinguishing features: Murolith (loxolith) coccoliths with a prominent inner rim cycle that is birefringent and conspicuous in cross-polarised light. This cycle is broader than the outer rim cycle. The central area is spanned by curving, diagonal cross-bars.

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 Valanginian Stage (0% up, 139.4Ma, in Valanginian 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

Roth, P. H. & Thierstein, H. R. (1972). Calcareous nannoplankton: Leg 14 of the Deep Sea Drilling Project. Initial Reports of the Deep Sea Drilling Project. 12: 546-559. gs


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Tegumentum compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-9-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11198 Go to Archive.is to create a permanent copy of this page - citation notes



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