Arkhangelskiellaceae


Classification: Mesozoic -> Arkhangelskiales -> Arkhangelskiellaceae
Sister taxa: Arkhangelskiellaceae, Kamptneriaceae,

Distinguishing features: Arkhangelskielids with shields predominantly formed of R-units, thus bright in cross-polarised light; V-units often form dark outer rim.


Daughter taxa: (blue => in age window 0-800Ma) Granddaughter taxa
R-units cover the distal surface, so coccolith appears bright, unicyclic, in LM (although darker towards outer edge); central-area has perforate plate with axial sutures. 4 tiers visible in side view.

Outer rim of V-units, with slight clockwise obliquity, visible on distal surface and form dark rim in LM; central-area spanned by an axial cross, grill or perforate plate. 3 tiers visible in side view.

Similar to Broinsonia but with well-developed central spine

Taxonomy:

Citation: Arkhangelskiellaceae Bukry, 1969 emend Bown & Hampton, 1997 in Bown & Young, 1997
Rank: Family
Type species: Type genus:Arkhangelskiella Vekshina, 1959.

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

Distinguishing features: Arkhangelskielids with shields predominantly formed of R-units, thus bright in cross-polarised light; V-units often form dark outer rim.


Morphology remarks: Tiered placolith coccoliths with central-areas spanned by axial crosses and grills, or filled by a perforate plate divided by axial sutures. The shields are typically bright in cross polarised light (rim dominated by R-unit) but bicyclic images are also observed.
Moshkovitz & Osmond (1989) analyse the birefringence pattern in detail.

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. & 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). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs

Bukry, D. (1969). Upper Cretaceous coccoliths from Texas and Europe. The University of Kansas Paleontological Contributions. Article 51 (Protista 2): 1-79. gs

Moshkovitz, S. & Osmond, K. (1989). The optical properties and microcrystallography of Arkhangelskiellaceae and some other calcareous nannofossils of the Late Cretaceous. In, Crux, J. A. & Heck, S. E. v. (eds) Nannofossils and their applications. Ellis Horwood, Chichester 76-97. gs

Vekshina, V. N. (1959). Coccolithophoridae of the Maastrichtian deposits of the West Siberian lowlands. Siberian Science Research Institute of Geology Geophysics Mineralogy and Raw Materials. 2: 56-81. gs


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Arkhangelskiellaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-10-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10042 Go to Archive.is to create a permanent copy of this page - citation notes



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