Nannotax3 - ntax_main - Markalius neuquenensis Nannotax3 - ntax_main - Markalius neuquenensis

Markalius neuquenensis


Classification: ntax_main -> Coccolith families inc sed -> Coccolith genera inc sed -> Markalius -> Markalius neuquenensis
Sister taxa: M. apertus, M. inversus, M. latus, M. neuquenensis, M. walvisensis, M. sp.

Taxonomy:

Citation: Markalius neuquenensis Guerra & Concheyro 2023
Taxonomic rank: species

Distinguishing features:
Parent taxon (Markalius): Circular placoliths with moderately birefringent shields, bright inner tube cycle and narrow or closed central areas.
This taxon: Like M.inversus but with a row of perforations on the tube

Farinacci & Howe catalog pages: M. neuquenensis *


Morphology:

Diagnosis: A Markalius species characterized by a broad, birefringent tube cycle divided into four sectors in XPL, each with at least one small perforation. The coccolith shape is circular to subcircular and it is medium to large in size. The tube cycle width is similar or slightly greater than the rim/shield and there is no central opening. The tube cycle is brighter at the edges where it connects to the shield. [Guerra & Concheyro 2023]

Remarks: M. neuquenensis is distinguished from other Markalius species by the wide tube cycle with perforations. Markalius inversus and M. latus show no perforations. In M. walvisensis, the tube cycle is much reduced and M. apertus has a central area opening. [Guerra & Concheyro 2023]

Search data:
LITHS: placolith, circular, elliptical, CA: pores, closed, CROSS-POLARS: rim-unicyclic, V-prominent, R-prominent,
Lith size: 6->9µm;
Data source notes: Guerra & Concheyro 2023 - and limits extended
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NP1 zone (65.47-66.04Ma, top in Danian stage). Data source: Guerra & Concheyro 2023
First occurrence (base): within CC26 zone (66.04-67.82Ma, base in Maastrichtian stage). Data source: Guerra & Concheyro 2023

Plot of occurrence data:

References:

Bown, P. R., Kim, H. & Gibbs, S. J. (2023). Danian calcareous nannofossil evolution and taxonomy with focus on sites from the North Atlantic Ocean (IODP Expedition 342, Sites U1403 and U1407). Journal of Nannoplankton Research. 41(2): 110-157. gs O

Guerra, R. M. & Concheyro, A. (2023). A new Markalius species from the Cretaceous/Paleogene boundary of the Neuquén Basin (Argentina). Journal of Nannoplankton Research. 41(2): 106-109. gs


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Markalius neuquenensis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 15-11-2025

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1813 Go to Archive.is to create a permanent copy of this page - citation notes



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