Nannotax3 - ntax_mesozoic - Markalius Nannotax3 - ntax_mesozoic - Markalius

Mesozoic Nannoplankton


Classification: ntax_mesozoic -> Heterococcoliths inc sedis -> placoliths inc sedis -> Markalius
Sister taxa: Ellipsolithus, Haqius, Markalius, Prolatipatella, Repagulum

Distinguishing features:
Parent taxon (placoliths inc sedis):
This taxon: Circular placoliths with moderately birefringent shields, a bright inner tube cycle and narrow or closed central areas.


Daughter taxa (time control age-window is: 0-800Ma)
Markalius inversus
Markalius with closed central area.
Markalius neuquenensis
Like M.inversus but with a row of perforations on the tube
Markalius vetulus
Medium sized (6-7.5 µm), tube cycle very bright  and individual elements not visible
Markalius sp.
Specimens not identified to species level

Taxonomy:

Citation: Markalius Bramlette & Martini, 1964
Type species: Cyclococcolithus leptoporus inversus Deflandre in Deflandre and Fert, 1954
Taxonomic discussion: Markalius is unique among placoliths in having both shields formed of V-units, hence placement in incertae sedies seems correct.

Farinacci & Howe catalog pages: Markalius + *

Distinguishing features:
Parent taxon (placoliths inc sedis):
This taxon: Circular placoliths with moderately birefringent shields, a bright inner tube cycle and narrow or closed central areas.


Morphology:

Varol 2023 showed that both shields of Markalius are formed from V-units.

Search data:
LITHS: placolith, circular, CA: closed, CROSS-POLARS: rim-unicyclic, V-prominent,
Lith size: 6->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

See also: Markalius - also occurs in the Palaeogene;

Geological Range:
Last occurrence (top): at top of NP21 zone (100% up, 32.9Ma, in Rupelian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Early Valanginian Substage (135.70-137.70Ma, base in Valanginian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Bramlette, M. N. & Martini, E. (1964). The great change in calcareous nannoplankton fossils between the Maestrichtian and Danian. Micropaleontology. 10(2): 291-322. gs

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

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs

Varol, O. (2023). New Paleocene calcareous nannofossils: Carlamuelleria, Davidbukrya, Mauriceblackia, Noelia and Senelia. Marine Micropaleontology. 180: 1-41. gs


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Mesozoic Nannoplankton compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 17-7-2024

Taxon Search:
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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10630 Go to Archive.is to create a permanent copy of this page - citation notes
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Comments (2)

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fatemeh(Guyana)

hi,

There isn't the species "Markalius circumradiatus" here.

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Jeremy Young(UK)

Hi, sorry for slow reply. The species is included in Haqius, so you can find it there. More generally you can use "search" to look for species and it in cases like these where the combination has changed it should send you in the right direction.