Nannotax3 - ntax_cenozoic - Pemma Nannotax3 - ntax_cenozoic - Pemma

Pemma


Classification: ntax_cenozoic -> Braarudosphaerales -> Braarudosphaeraceae -> Pemma
Sister taxa: Braarudosphaera, Hexadelus, Micrantholithus, Pemma, Pentaster

Daughter taxa (time control age-window is: 0-800Ma)
Pemma basquense
Pemma with crenulate edges.
Pemma bybelliae
Large, circular Pemma with a diagnostic thin base with crenulated edges. Central area consists of a layer of basal thickenings superimposed on the base, resulting in a hazy appearance of the outer edge of the nannolith and a central area more highly birefringent than the edges.
Pemma papillatum
Pemma with multiple nodes along the outer margin of each pentalith.
Pemma rotundum
Circular Pemma species
Pemma stradneri
Angular Pemma species with ray tips extending beyond the pentagonal periphery
Pemma uncinata
Large (typically >7 µm), triangular-, rectangular- or rhomb-shaped nannoliths, which are thickened along two sides (‘base’ and ‘side’) to give a hook-shaped appearance. Dark in XPL but birefringent where thickened; c-axis orientation is parallel with the long axis.
Pemma sp.
Specimens which cannot be assigned to any established species

Taxonomy:

Citation: Pemma Klumpp, 1953
taxonomic rank: Genus
Type species: Pemma rotundum Klumpp, 1953

Distinguishing features:
Parent taxon (Braarudosphaeraceae): Coccospheres pentagonal dodecahedra formed of five pentagonal plates
This taxon: Pentaliths with a central depression/perforation in each segment; often producing elevated, robust structures that are commonly observed in side view.

Farinacci & Howe catalog pages: Pemma *

Search data:
LITHS: nannolith-radiate, pentagonal, CA: pores, CROSS-POLARS: T-prominent,
Lith size: 5->18┬Ám; Segments: 5->5;
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 NP21 zone (100% up, 32.9Ma, in Rupelian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NP14b subzone (46.29-47.84Ma, base in Lutetian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:


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Pemma compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 26-5-2024

Taxon Search:
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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1034 Go to Archive.is to create a permanent copy of this page - citation notes
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