Braarudosphaerales


Classification: Mesozoic -> Braarudosphaerales
Sister taxa: Arkhangelskiales, Eiffellithales, Stephanolithiales, Podorhabdales, Watznaueriales, Syracosphaerales, Heterococcoliths inc sedis, Holococcoliths, Braarudosphaerales, Nannoliths inc sedis, Mesozoic non–coccoliths, hidden,

Short diagnosis: Nannoliths formed of multiple layers of thin elements, arranged with rotational symmetry, and showing tangential c-axis orientations.


Daughter taxa (blue => in age window 0-300Ma) Granddaughter taxa
Nannoliths constructed from 5 (rarely 6) segments which form a pentalith (a five-sided plate); C-axes tangential to pentalith outline in plan view; individual crystal units show laminar ultrastructure.

Conical, globular or cylindrical nannoliths composed of plates spirally-arranged around an axial cavity or canal. Plate c-axes are arranged tangentially to the longitudinal axis.

Taxonomy:

Citation: Braarudosphaerales Aubry 2013 emend Lees & Bown 2016
Rank: Order
Notes & discussion: Lees & Bown (2016) emended the order Braarudosphaerlaes to include the Nannoconaceae on the grounds that pentaliths and nannoconids both showed structures formed of multiple layers of thin elements. In the case of pentaliths these thin elements appear as laminae witin individual crystal units, in nannoconids they are stacked with offset, both groups appear at the end Jurassic and show tangential c-axis orientations as well as simple rotational symmetry, (without modification by central area structures or elongation into elliptical forms) 
Other possibly related taxa which show tangential c-axes and simple rotional symettry but not stacked layers of elements include the Polycylcolithaceae and the genera Kokia, Polycostella, Rucinolithus and Tegulalithus.

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

Short diagnosis: Nannoliths formed of multiple layers of thin elements, arranged with rotational symmetry, and showing tangential c-axis orientations.

Geological Range:
Last occurrence (top): Extant Data source: Total of range of species in this database
First occurrence (base): within Oxfordian Stage (157.25-163.47Ma, base in Oxfordian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Aubry, M.-P., (2013). Cenozoic Coccolithophores: Braarudosphae­rales. Atlas of Micropaleontology Series. Micropaleontology Press, New Yourk, 336 pp.

Lees, J.A. & Bown, P.R., (2016). New and intriguing calcareous nannofossils from the Turonian (Upper Cretaceous) of Tanzania. Journal of Nannoplankton Research, 36(1): 83-95.


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Braarudosphaerales compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 16-12-2017

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