Nannotax3 - ntax_mesozoic - Amphizygus

Amphizygus


Classification: ntax_mesozoic -> Eiffellithales -> Chiastozygaceae -> Amphizygus
Sister taxa: Amphizygus, Archaeozygodiscus, Gorkaea, Placozygus, Reinhardtites, Tranolithus, Zeugrhabdotus ⟩⟨ Chiastozygus ⟩⟨ Staurolithites, Diadorhombus, Rhabdophidites ⟩⟨ Ahmuellerella, Bukrylithus, Diloma, Heteromarginatus, Misceomarginatus, Monomarginatus, Vacherauvillius ⟩⟨ Braloweria, Clepsilithus, Crepidolithus, Loxolithus, Neocrepidolithus, Tubirhabdus, C. - unidentified

Distinguishing features:
Parent taxon (Chiastozygaceae): Typical Eiffelithales - rim with well outer/upper clockwise-imbricate V-units and lower/inner R-units. Central area open or spanned by disjunct cross or bar supporting a spine.
This taxon: Muroliths with bicyclic rim and tranverse bar formed from laths which continue around the inner edge of the rim, delineating the two circular perforations.


Daughter taxa (time control age-window is: 0-800Ma)
Amphizygus brooksii
Bicyclic muroliths with complex transverse bar, formed from laths which continue around the inner edge of the rim, delineating the two circular perforations.
Amphizygus microminutus
Very small (<3 µm) murolith coccolith with transverse bar and spine
Amphizygus minimus
Small Amphizygus.
Amphizygus sp.
Specimens not identified to species level

Taxonomy:

Citation: Amphizygus Bukry, 1969
Rank: Genus
Type species: Amphizygus brooksii Bukry, 1969
Synonyms: Bipodorhabdus Noël 1970 (B. tesselatus the type of Bipodorhabdus is a junior synonym of A. brooksii the type of Amphizygus)

Farinacci & Howe catalog pages: Amphizygus * , Bipodorhabdus *

Distinguishing features:
Parent taxon (Chiastozygaceae): Typical Eiffelithales - rim with well outer/upper clockwise-imbricate V-units and lower/inner R-units. Central area open or spanned by disjunct cross or bar supporting a spine.
This taxon: Muroliths with bicyclic rim and tranverse bar formed from laths which continue around the inner edge of the rim, delineating the two circular perforations.

Search data:
TagsLITHS: murolith, elliptical, CA: ca_disjunct, bar, CROSS-POLARS: rim-bicyclic, V-prominent,
MetricsLith size: 4->9µm;
Data source notes: size range of included species
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Albian Stage (0% up, 113Ma, in Aptian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

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

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs V O


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Amphizygus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 22-1-2022

Taxon Search:
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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10013 Go to Archive.is to create a permanent copy of this page - citation notes



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