Sikoraea


Classification: Mesozoic -> Nannoliths inc sedis -> Nannoliths inc sed - radiate multielement -> Sikoraea
Sister taxa: Acadialithus, Assipetra, Hayesites, Phosterolithus, Rucinolithus, Sikoraea,

Distinguishing features: Birefringent and fusiform nannolith having a smooth surface with longitudinal slits which are confined to its apex, leaving an un-pierced section in the middle.


Daughter taxa: (blue => in age window 0-800Ma)
Birefringent and fusiform nannolith having a smooth surface with longitudinal slits which are confined to its apex.

Taxonomy:

Citation: Sikoraea Varol & Bowman 2019
Rank: Genus
Type species: Sikoraea steinhaueri Varol & Bowman 2019
Notes & discussion: It appears different than any other genus and is difficult to compare

Farinacci & Howe catalog pages: Sikoraea [no catalog entry yet]

Distinguishing features: Birefringent and fusiform nannolith having a smooth surface with longitudinal slits which are confined to its apex, leaving an un-pierced section in the middle.


Morphology remarks: Sikoraea is birefringent in both plan and side views and has an axial (radial) c-axis, which is parallel to the length of the nannolith. In side view, species are elliptical with the longitudinal slits confined to its apex. The slits do not extend to the lateral axis. In plan view, species are subcircular to circular, with eight radiating ridges. The ridges alternate between narrow and wider sizes. The narrow ridges interlock into slits but are not usually visible in side view. [Varol & Bowman 2019]

Geological Range:
Last occurrence (top): at top of Tithonian Stage (100% up, 145Ma, in Tithonian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Tithonian Stage (0% up, 152.1Ma, in Tithonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Varol, O. & Bowman, A. R. (2019). Taxonomic revision of selected Late Jurassic (Tithonian) calcareous nannofossils and the application of mobile mounting. Neues Jahrbuch für Geologie und Paläontologie Abhandlungen. 291: 65-87. gs


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Sikoraea compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-10-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11371 Go to Archive.is to create a permanent copy of this page - citation notes



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