Nannotax3 - ntax_cenozoic - Rhabdosphaera xiphos Nannotax3 - ntax_cenozoic - Rhabdosphaera xiphos

Rhabdosphaera xiphos


Classification: ntax_cenozoic -> Syracosphaerales -> Rhabdosphaeraceae -> Rhabdosphaera -> Rhabdosphaera xiphos
Sister taxa: R. clavigera, R. gracilenta, R. poculii, R. vitrea, R. xiphos, R. sp.

Taxonomy:

Citation: Rhabdosphaera xiphos (Deflandre & Fert 1954) Norris, 1984
Taxonomic rank: species
Basionym: Rhabdolithus xiphos Deflandre & Fert 1954

Distinguishing features:
Parent taxon (Rhabdosphaera): Coccoliths without radial lath cycle; coccospheres dimorphic, only some spine-bearing
This taxon: Long delicate spines with collar near base

Farinacci & Howe catalog pages: R. xiphos *


Morphology:

Ordinary liths broadly elliptical. About 9 relatively large, imbricate, plates of lamellar cycle, produce a distinctive star pattern on the distal surface. Spine-bearing liths circular, spines long (6-7 µm) delicate and tapering, with collar near base.

Size:
Coccolith 1-2 µm across, spines 5-8 µm long


Biology & life-cycles

Supraha et al. (2018) illustrate  a single combination coccosphere with R. xiphos heterococcoliths and rather poorly formed holococcoliths. The holococcoliths are suggested to resemble Calicasphaera blokii and Calyptrosphaera dentata, but are too poorly formed for either identification to be certain. Another possible combination coccosphere, with Corisphaera gracilis is illustrated here (Young & Geisen unpublished). This second one was previously interpreted as an accidental association but taken together with the combination coccosphere of Supraha etal. 2018 it is more intriguing.

Search data:
LITHS: planolith, elliptical, CA: ca_disjunct, process,
CSPH: equant, BC-dimorphic, CROSS-POLARS: R-prominent,
Lith size: 5->8µm; Coccosphere size: 15->20µm; Liths per sphere: 35->65
Data source notes: lith length from illustrated specimens; csph data from Cros & Fortuño 2003; lith numbers from Yang & Wei 2003, range inferred from single estimate
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 NP19-20 zone (34.44-36.97Ma, base in Priabonian stage). Data source: Dunkley Jones et al., 2009

Plot of occurrence data:

References:

Cros, L. & Fortuño, J. -M. (2002). Atlas of northwestern Mediterranean coccolithophores. Scientia Marina. 66: 1-186. gs

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs

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

Kleijne, A. (1992). Extant Rhabdosphaeraceae (coccolithophorids, class Prymnesiophyceae) from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Scripta Geologica. 100: 1-63. gs

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

Supraha, L., Ljubesic, Z. & Henderiks, J. (2018). Combination coccospheres from the Eastern Adriatic coast: New, verified and possible life-cycle associations. Marine Micropaleontology. 141: 23-30. gs

Winter, A., Reiss, Z. & Luz, B. (1979). Distribution of living coccolithophore assemblages in the Gulf of Elat ('Aqaba). Marine Micropaleontology. 4: 197-223. gs

Yang, T. -N., Wei, K. & Wu, J. -T. (2012). Marine coccolithophores around Taiwan. Biodiversity Research Center, Academica Sinica, Taipei. 1-96. 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. S1: 1-132. gs


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Rhabdosphaera xiphos 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=1200 Go to Archive.is to create a permanent copy of this page - citation notes
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