Nannotax3 - ntax_mesozoic - Common genera

Common genera


Classification: ntax_mesozoic -> Holococcoliths -> Common genera
Sister taxa: Common genera, Rarer genera

Distinguishing features:
Parent taxon (Holococcoliths): Coccoliths formed of minute (ca 0.1µm) rhombohedral micro-crystals. Often a life-cycle stage with heterococcolith counterpart(s).
This taxon: The four most commonly recorded genera


Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Calculites
Holococcoliths with a proximal plate of four blocks; ridged and pitted distal surface; and short, narrow, hollow spines. Entire coccolith bright in xpl in plan view

Lucianorhabdus
Holococcoliths with a proximal plate of four blocks and tall, hollow spines, which are often ridged or pitted and may be bulbous or curved.

Orastrum
Holococcoliths with narrow rim surrounding a central-area formed of 1-4 blocks. Typically non-cavate with no spine. Rim bright and central plate dark
O. schollei
O. asarotum
O. campanensis
O. porosuturalis
O. perspicuum
O. robinsonii
O. colligatum
O. sp.

Owenia
Holococcoliths with a narrow rim and a central structure comprising two or four blocks which typically incorporate a distal bridge-shaped structure which may extend into a spine; the blocks may be perforate.
O. dispar
O. hillii
O. partitum
O. sp.

Taxonomy:

Rank: informal group of genera

Farinacci & Howe catalog pages: Common genera [no catalog entry yet]

Distinguishing features:
Parent taxon (Holococcoliths): Coccoliths formed of minute (ca 0.1µm) rhombohedral micro-crystals. Often a life-cycle stage with heterococcolith counterpart(s).
This taxon: The four most commonly recorded genera

Search data:
TagsLITHS: holococcolith,
MetricsLith size: 0->0µm;
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): in mid part of Valanginian Stage (54% up, 136.4Ma, in Valanginian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:


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Common genera compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 25-9-2021

Taxon Search:
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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10268 Go to Archive.is to create a permanent copy of this page - citation notes



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