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:
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.
LITHS: planolith, elliptical, CA: ca_disjunct, grill, process, CSPH: equant, |
Lith size: 1.5->5µm; Coccosphere size: 7->25µm; |
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:
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. gsReferences:
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Algirosphaera compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-2-2025
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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