Nannotax3 - ntax_main - Reticulofenestra onusta Nannotax3 - ntax_main - Reticulofenestra onusta

Reticulofenestra onusta


Classification: ntax_main -> Isochrysidales -> Noelaerhabdaceae -> Reticulofenestra -> R. lockeri group -> Reticulofenestra onusta
Sister taxa: R. chriskingii, R. daviesii, R. gartneri, R. lockeri, R. onusta, R. macmillanii, R. martinii ⟩⟨ R. nicolasii


Taxonomy:
Citation: Reticulofenestra onusta (Perch-Nielsen 1971) Wise 1983
Taxonomic rank: species
Basionym: Dictyococcites onustus Perch-Nielsen, 1971

Synonyms:

Distinguishing features:
Parent taxon (R. lockeri group): Elliptical reticulofenestrids with relatively open central area spanned on the proximal surface by a robust grill (clearly visible in lm as a birefringent plate with variable number of perforations).
This taxon: Large to very large (>10 µm) with wide central area, net weakly visible in LM


Morphology:
Large to very large, distinctive elliptical reticulofenestrids with a wide central area spanned by a finely perforate, weakly birefringent net. [Bown & Newsam 2017]

Differentiation: Distinguised from other R. lockeri group coccoliths by large size, wider central area and clearly visibly fine perforations across the net [Bown & Newsam 2017]

Size:
L = ~11.0–12.5μm

Search data:
LITHS: placolith, elliptical, CA: ca_conjunct, grill, closed,
CSPH: equant, monomorphic, CROSS-POLARS: rim-unicyclic, R-prominent,
Lith size: 10->14µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP15c subzone (42.87-44.12Ma, top in Lutetian stage). Data source: Bown & Newsam 2017
First occurrence (base): within NP15b subzone (44.12-45.49Ma, base in Lutetian stage). Data source: Bown & Newsam 2017

Plot of occurrence data:

References:

Bown, P. R. & Newsam, C. (2017). Calcareous nannofossils from the Eocene North Atlantic Ocean (IODP Expedition 342 Sites U1403–1411). Journal of Nannoplankton Research. 37(1): 25-60. gs O

De Kaenel, E. & Mojon, P. -O. (2023). Calcareous nannofossil biostratigraphy of the Eocene/Oligocene boundary (Zones NP19–21) in the parautochthonous Subalpine UMM of the Swiss Molasse Basin (Canton Fribourg, Western Switzerland). Journal of Nannoplankton Research. 41(2): 64-96. gs O

Perch-Nielsen, K. (1971c). Elektronenmikroskopische untersuchungen an Coccolithen und verwandten Formen aus dem Eozan von Danemark. Biologiske Skrifter, Kongelige Danske Videnskabernes Selskab. 18(3): 1-76. gs O

Wise, S. W. (1983). Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 71 in the Falkland Plateau region, Southwest Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project. 71: 481-550. gs O


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Reticulofenestra onusta compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-7-2026

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1178 Go to Archive.is to create a permanent copy of this page - citation notes



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