Nannotax3 - ntax_cenozoic - Reticulofenestra sessilis

Reticulofenestra sessilis

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


Citation: Reticulofenestra sessilis (Lohmann 1912) Jordan & Young, 1990
Rank: Species
Basionym: Pontosphaera sessilis Lohmann 1912
Taxonomic discussion: Unambiguous Reticulofenestra disappears in the Early Quaternary but there are small reticulofenestrids without bridges though the Quaternary and a couple of extant species, including R. sessilis (see Young 2005), these are conventionally referred to Reticulofenestra but may prove to have descended from Gephyrocapsa by loss of the bridge.

Distinguishing features:
Parent taxon (Reticulofenestra): No bridge, no slits
This taxon: Closed central area. Rather heavily calcified giving irregular form, strongly crenulate margin.

Farinacci & Howe catalog pages: P. sessilis * , C. taiwanea *


Coccospheres 6-10 µm; liths 2.5-4 µm.

Ecology & Biogeography

Occurs almost exclusively in symbiotic(?) associations with a centric diatom of the genus Thalassiosira. Deep photic.

Biology & life-cycles

Phylogenetic relations

Cultures: Strains of this species are maintained in culture, for details see Roscoff Culture Collection.

Search data:
LITHS: placolith, elliptical, CA: ca_conjunct, closed,
CSPH: equant, monomorphic, CROSS-POLARS: rim-unicyclic, R-prominent,
Lith size: 2.5->4µm; Coccosphere size: 6->10µm; Liths per sphere: 10->30
Data source notes: RCC
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (Young et al. 2003)
First occurrence (base): within Quaternary Period (0.00-2.59Ma, base in Gelasian stage). Data source: [JRY rough estimate]

Plot of occurrence data:


Chen, M. -P. (1980). Modern and redeposited coccolithophores for the indication of sediment dispersal pattern around Taiwan offshore region. Acta Oceanographica Taiwanica. 11: 129-156. gs

Lohmann, H. (1912). Untersuchungen über das Pflanzen- und Tierleben der Hochsee, zugleich ein Bericht über die biologischen Arbeiten auf der Fahrt der "Deutschland" von Bremerhaven nach Buenos-Aires in der Zeit vom 7. Mai bis 7. September 1911. Veröffentlichungen des Instituts für Meereskunde an der Universität Berlin, Neue Folge. A. Geographisch-naturwissenschaftliche Reihe. 1: 1-92. gs V O

Okada, H. & McIntyre, A. (1977). Modern coccolithophores of the Pacific and North Atlantic Oceans. Micropaleontology. 23(1): 1-55. gs

Reid, F. M. H. (1980). Coccolithophorids of the North Pacific Central Gyre with notes on their vertical and seasonal distribution. Micropaleontology. 26(2): 151-176. gs

Young, J. R., Geisen, M., Cros, L., Kleijne, A., Probert, I. & Ostergaard, J. B. (2003). A guide to extant coccolithophore taxonomy. Journal of Nannoplankton Research, Special Issue. 1: 1-132. gs V O


Reticulofenestra sessilis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 30-11-2022

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