Nannotax3 - ntax_cenozoic - Algirosphaera Nannotax3 - ntax_cenozoic - Algirosphaera

Algirosphaera


Classification: ntax_cenozoic -> Syracosphaerales -> Rhabdosphaeraceae -> Algirosphaera
Sister taxa: Acanthoica, Algirosphaera, Blackites, Cyrtosphaera, Discosphaera, Palusphaera, Rhabdosphaera, Solisphaera

Daughter taxa (time control age-window is: 0-800Ma)
Algirosphaera cucullata
Coccoliths rounded, protrusion formed of needle-like elements without tile cover
Algirosphaera fabaceus
Coccoliths elongate, protrusion with internal rods in two superposed sets (vertical and oblique) and tile cover
Algirosphaera meteora
Coccoliths have a rounded protrusion with tile cover, but no internal rods
Algirosphaera robusta
Coccoliths elongate, protrusion with internal rods and tile cover
Algirosphaera sp.
Specimens which cannot be assigned to established species

Taxonomy:

Citation: Algirosphaera Schlauder, 1945 emend. Norris, 1984
Taxonomic rank: genus
Type species: Anthosphaera oryza Schlauder 1954, which is a subjective junior synonym ofAlgirosphaera robusta (Lohman 1902).
Taxonomic discussion: Of the species included here the fossil species A. fabaceus has structure closest to the type species A. robusta. The other two extant species have rather different protrusion structures and may prove not to be directly related.

Distinguishing features:
Parent taxon (Rhabdosphaeraceae): BCs planoliths with radial lath cycle and highly-variable axial structures. Often polymorphic and/or varimorphic
This taxon: Body coccoliths with well-developed radial lath cycle; domal or double-lipped protrusion; coccosphere dimorphic, CFCs larger and taller

Farinacci & Howe catalog pages: Algirosphaera


Morphology:


Coccosphere: monomorphic or with differentated CFCs.
Coccoliths: Rim and radial cycle show typical Rhabdosphaeraceae structure, but lamellar cycle is modified into/replaced by an elongate domal or double-lipped (labiatiform) protrusion, which is filled by fine rod-like elements.

Search data:
LITHS: planolith, elliptical, CA: ca_disjunct, grill, process,
CSPH: equant,
Lith size: 1.5->5µm; Coccosphere size: 7->25µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: There are rare Neogene records of A. robusta and A. meteora and fossil species were recently described, from Tanzania, by Bown et al. (2009)
Last occurrence (top): Extant. Data source: Total of ranges of the species in this database
First occurrence (base): within NP19-20 zone (34.44-36.97Ma, base in Priabonian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Dunkley Jones, T., Bown, P. R. & Pearson, P. (2009). Exceptionally well preserved upper Eocene to lower Oligocene calcareous nannofossils (Prymnesiophycidae) from the Pande Formation (Kilwa Group), Tanzania. Journal of Systematic Palaeontology. 7(4): 359-411. gs

Norris, R. E. (1984). Indian Ocean nanoplankton. I. Rhabdosphaeraceae (Prymnesiophyceae) with a review of extant taxa. Journal of Phycology. 20: 27-41. gs

Schlauder, J. (1945). Recherches sur les flagellés calcaires de la Baie d'Alger. PhD thesis, Université d'Alger. 1-51. gs


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Algirosphaera compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-2-2025

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=18 Go to Archive.is to create a permanent copy of this page - citation notes
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