C. floridanus group

Classification: ntax_cenozoic -> Isochrysidales -> Noelaerhabdaceae -> Reticulofenestra -> C. floridanus group
Sister taxa: C. floridanus group, R. bisecta group, R. lockeri group, R. parvula group, R. pseudoumbilicus group, R. reticulata group, R. umbilicus group, R. sp.

Daughter taxa (time control age-window is: 0-800Ma)
Cyclicargolithus abisectus
Coccoliths large (>11µm), usually sub-circular.
Cyclicargolithus bukryi
Small (3-6 µm), sub-circular with broad central opening (ca 20-25% of coccolith width)
Cyclicargolithus floridanus
Coccoliths circular to sub-circular with small central-area, <11µm in width.
Cyclicargolithus luminis
Medium sized circular reticulofenestrids with narrow, closed central area.
Cyclicargolithus parvus
Small (3-5µm) circular reticulofenestrid with narrow or closed central area and few elements (individual elements clearly visible in lm)
Cyclicargolithus sp.
Specimens which cannot be assigned to established species


Citation: C. floridanus group
Rank: species group
Synonyms: Cyclicargolithus Bukry 1971
Taxonomic discussion: The genus Cyclicargolithus Buky 1971 is widely used and the taxonomic concept is straightforward - circular reticulofenestrids with a narrow central area. However, these intergrade with Reticulofenestra, so it can be difficult to assign some specimens. Moreover the genus is phylogenetically problematic since it is likely that it both evolved from a Paleogene Reticulofenestra species and gave rise to Neogene Reticulofenestra species. So, we regard Cyclicargolithus as a sub-group of Reticulofenestra rather than a genuinely separate genus.

Distinguishing features: Subcircular to broadly-elliptical reticulofenestrids with a narrow central area (spanned by delicate proximal net, not visible in lm)

Farinacci & Howe catalog pages: Cyclicargolithus *

Search data:
MetricsLith size: 3->16µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Common in the Eocene and dominant, lower Oligocene-lower Miocene.
Last occurrence (top): in upper part of Serravallian Stage (80% up, 12.1Ma, in Serravallian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Thanetian Stage (62% up, 57.2Ma, in Thanetian stage). Data source: Total of range of species in this database

Plot of occurrence data:


Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs V O

Bukry, D. (1971b). Cenozoic calcareous nannofossils from the Pacific Ocean. San Diego Society of Natural History Transactions. 16: 303-327. gs


C. floridanus group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 7-3-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=165 Go to Archive.is to create a permanent copy of this page - citation notes

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