Helicosphaera pavimentum HOL


Classification: ntax_cenozoic -> Holococcoliths -> flat-topped -> Helicosphaera HOL -> Helicosphaera pavimentum HOL
Sister taxa: H. HOL catilliferus type, H. HOL confusus type, H. HOL ponticuliferus type, H. pavimentum HOL

Taxonomy:

Citation: Helicosphaera HOL dalmaticus type informal
Rank: species
Basionym: Syracosphaera dalmatica Kamptner 1927
Synonyms:
Taxonomic discussion: Nomenclature here follows Young & Bown (2014)

Distinguishing features: Liths with open centre spanned by broad central mound from which 4-6 irregular ridges radiate defining pores.

Farinacci & Howe catalog pages: S. dalmatica *


Morphology: Outer part of disk similar to S. catilliferus, inner part appears to be open, but spanned by the central mound with 4-6 irregular ridges radiating from this to define pores. Distinct central opening on proximal side, and it is likely that beneath the central mound a cavity extends to the proximal surface. Differentiation of this taxon from confusus is discussed at length in Kleijne 1991.

Size: Liths 2-3 µm long; disk 6-7 crystallites high


Biology & life-cycles: Possible combination coccosphere with H. wallichii HET was observed by Young & Geisen 2002, and a rather more likely combination coccosphere with H. pavimentum HET observed by Triantaphyllou et al. 2016. 
A further combination cocccosphere of H. pavimentum and S. dalmaticus is shown here, from the research collection of Dr. Jasna Arapov (Inst Oceanography & Fisheries, Croatia). This strongly supports the life-cycle association of the two species, so the taxonomy now needs to be revised. [my interpretation - JRY 2019]

See also: Helicosphaera wallichii ;Helicosphaera pavimentum ;

Search data:
TagsLITHS: holococcolith, elliptical, CA: pores, process,
CSPH: equant, monomorphic, CROSS-POLARS: 1ou, R-prominent,
MetricsLith size: 2.4->3.3µm; Coccosphere size: 10->12µm; Liths per sphere: 45->100
Data source notes: morphom data from Yang & Wei (2003), Cros & Fortuño (2002) & Kleijne 1991
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:

References:

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

Kamptner, E. (1927). Beitrag zur Kenntnis adriatischer Coccolithophoriden. Archiv für Protistenkunde. 58: 173-184. gs

Kleijne, A. (1991). Holococcolithophorids from the Indian Ocean, Red Sea, Mediterranean Sea and North Atlantic Ocean. Marine Micropaleontology. 17: 1-76. gs

Loeblich, A. R. & Tappan, H. (1963). Type fixation and validation of certain calcareous nannoplankton genera. Proceedings of the Biological Society of Washington. 76: 191-198. gs

Loeblich, A. R. & Tappan, H. (1966). Annotated index and bibliography of the calcareous nannoplankton. Phycologia. 5: 81-216. gs

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

Triantaphyllou, M. et al. (2016). Coccolithophore combination coccospheres from the NE Mediterranean Sea: new evidence and taxonomic revisions. Micropaleontology. 61(6): 457-472. 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

Young, J. R. & Bown, P. R. (2014). Some emendments to calcareous nannoplankton taxonomy. Journal of Nannoplankton Research. 33(1): 39-46. gs V O

Young, J. R. & Geisen, M. (2002). Xenospheres – associations of coccoliths resembling coccospheres. Journal of Nannoplankton Research. 24(1): 27-35. gs V O

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

Young, J. R., Arapov, J., Skejic, S., Bakrac, A., Buzancic, M. & Triantaphyllou, M. (2020). Verification of the life-cycle of Helicosphaera pavimentum, and discussion of the identity of Syracolithus dalmaticus. Journal of Nannoplankton Research. 30(1): 41-47. gs V O


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Helicosphaera pavimentum HOL compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-4-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=665 Go to Archive.is to create a permanent copy of this page - citation notes



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Ines Galovic (Zagreb, Croatia)

This is also characteristic Paratethyan species for mid-Miocen (Badenian) of Slovenia, Croatia and Romania (our article).

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