Nannotax3 - ntax_mesozoic - Biscutum depravatum Nannotax3 - ntax_mesozoic - Biscutum depravatum

Biscutum depravatum


Classification: ntax_mesozoic -> Podorhabdales -> Biscutaceae -> Biscutum -> Biscutum depravatum
Sister taxa: B. constans, B. ellipticum ⟩⟨ B. coronum, B. dekaenelii, B. magnum, B. melaniae ⟩⟨ B. arrogans, B. asymmetricum, B. boletum, B. dissimilis, B. zulloii ⟩⟨ B. hattneri, B. notaculum, B. virginica ⟩⟨ B. gaultensis, B. thurowii ⟩⟨ B. davyi, B. depravatum, B. dorsetensis, B. dubium, B. erismatum, B. grande, B. intermedium, B. planum, B. profundum, B. sp.

Distinguishing features:
Parent taxon (Biscutum): Elliptical with broad shields with or without a prominent inner tube cycle; the central-area may be imperforate or narrow and vacant or spanned by a simple structure (plate, cross or bar).
This taxon: Normally elliptical Biscutum with relatively narrow shields and open central area spanned by cross bars slightly rotated from axial. Unicyclic image in XPL.


Taxonomy:

Citation: Biscutum depravatum (Grün & Zweili, 1980) Bown, 1987
taxonomic rank: Species
Basionym: Axopodorhabdus depravatus Grün & Zweili, 1980
Taxonomic discussion: Often cited as B. depravatus but the correct form is B. depravatum, as noted by van Heck (1990)

Farinacci & Howe catalog pages: A. depravatus *

Distinguishing features:
Parent taxon (Biscutum): Elliptical with broad shields with or without a prominent inner tube cycle; the central-area may be imperforate or narrow and vacant or spanned by a simple structure (plate, cross or bar).
This taxon: Normally elliptical Biscutum with relatively narrow shields and open central area spanned by cross bars slightly rotated from axial. Unicyclic image in XPL.

Search data:
LITHS: placolith, elliptical, CA: ca_disjunct, process, diagonal cross, CROSS-POLARS: rim-unicyclic, V-prominent,
Lith size: 5->7µm;
Data source notes: original description
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Middle Oxfordian Substage (156.60-159.40Ma, top in Oxfordian stage). Data source: Bown & Cooper 1998
First occurrence (base): within Aalenian Stage (170.90-174.70Ma, base in Aalenian stage). Data source: Bown & Cooper 1998

Plot of occurrence data:

References:

Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 34-85. gs O

Bown, P. R. (1987a). Taxonomy, evolution, and biostratigraphy of Late Triassic-Early Jurassic calcareous nannofossils. Special Papers in Palaeontology. 38: 1-118. gs

Grün, W. & Zweili, F. (1980). Das kalkige Nannoplankton der Dogger-Malm-Grenze im Berner Jura bei Liesberg (Schweiz). Jahrbuch der Geologischen Bundesanstalt. 123: 231-341. gs

van Heck, S. E. (1990). The ICBN: Things you need to know - 1. INA Newsletter. 12(1): 19-20. gs

Missing or ambiguous references: ;


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Biscutum depravatum compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-2-2024

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10075 Go to Archive.is to create a permanent copy of this page - citation notes
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