Distinguishing features:
Parent taxon (Quadrum): Stellate to cubiform nannoliths with walls formed from two cycles of 4-9 elements and no central opening or diaphragm. When cubiform, the elements are joined along sutures that go out to the mid-point of the 'cube' edges.
This taxon: Quadrum with 7 elements per cycle
Taxonomy:
Farinacci & Howe catalog pages: Q. eptabrachium *
Distinguishing features:
Parent taxon (Quadrum): Stellate to cubiform nannoliths with walls formed from two cycles of 4-9 elements and no central opening or diaphragm. When cubiform, the elements are joined along sutures that go out to the mid-point of the 'cube' edges.
This taxon: Quadrum with 7 elements per cycle
Morphology:
Size:
Tags | LITHS: nannolith-radiate, star-shaped, CA: closed, CROSS-POLARS: T-prominent, |
Metrics | Lith size: 3->6µm; Segments: 7->7; Data source notes: original description & illustrated specimens |
Geological Range:
Last occurrence (top): within Santonian Stage (83.64-86.26Ma, top in Santonian stage). Data source: Burnett 1998
First occurrence (base): within Turonian Stage (89.77-93.90Ma, base in Turonian stage). Data source: Burnett 1998
Plot of occurrence data:
Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs O Varol, O. (1992b). Taxonomic revision of the Polycyclolithaceae and its contribution to Cretaceous biostratigraphy. Newsletters on Stratigraphy. 27(93-127): -. gsReferences:
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Quadrum eptabrachium compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 13-8-2022
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10969 Go to Archive.is to create a permanent copy of this page - citation notes |
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