Nannotax3 - ntax_cenozoic - Calcidiscus leptoporus subsp. quadriperforatus HOL

Citation: Calcidiscus leptoporus subsp. quadriperforatus (Kamptner 1937) Geisen et al., 2002 HOL

Basionym: Syracosphaera quadriperforata Kamptner 1937

Synonyms:

Syracolithus quadriperforatus (Kamptner 1937) Gaarder, in Heimdal & Gaarder 1980
Homzygosphaera quadriperforata (Kamptner 1937) Gaarder 1962
Calcidiscus quadriperforatus HOL

Taxonomic discussion: Previously assigned to Syracolithus quadriperforatus (Kamptner 1937) Gaarder 1962

Distinguishing features:
Parent taxon (septate): Holococcoliths with tube, open distally and subdivided internally by vertical septae
This taxon: Internal walls define 4-6 pores. Tube 10-15 crystallites high, castellated, higher where it meets internal walls. Tube sometimes double-layered, base open.

Coccolith structure - coccoliths are open tubes with internal septae (walls). The outer tube wall shows hexagonal fabric and the crystallites have radial c-axes (birefringent in plan view in LM). In SEM the fabric of the septae is not obviously different from that of the wall, but they are non-birefringent in plan view in LM and so the calcite crystallites must have vertical c-axes. The septae can extend along the inner margin of the tube forming a double wall, but they do not always do this.
Coccospheres monomorphic, spherical (this is a characteristic feature in LM).

The association of this holococcolith with the large Calcidiscus leptoporus (sensu lato) morphotype is still based on a single specimen, from the Western Mediterranean, but it is an exceptionally clear combination coccosphere (Geisen et al. 2002).

Geological Range:
Last occurrence (top): Extant. Data source: present in the plankton (Young et al. 2003)
First occurrence (base): within Miocene Epoch (5.33-23.03Ma, base in Aquitanian stage). Data source: [JRY rough estimate]

References:

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

Gaarder, K. R. (1962). Electron Microscope Studies on Holococcolithophorids. Nytt Magasin for Botanikk. 10: 35-51. gs O

Geisen, M., Billard, C., Broerse, A. T. C., Cros, L., Probert, I. & Young, J. R. (2002a). Life-cycle associations involving pairs of holococcolithophorid species: intraspecific variation or cryptic speciation? European Journal of Phycology. 37: 531-550. gs

Heimdal, B. R. & Gaarder, K. R. (1980). Coccolithophorids from the northern part of the eastern central Atlantic I. Holococcolithophorids. “Meteor” Forschungsergebnisse. 32: 1-14. gs

Kamptner, E. (1937). Neue und bemerkenswerte Coccolithineen aus dem Mittelmeer. Archiv für Protistenkunde. 89: 279-316. gs

Keuter, S., Young, J. R., Koplovitz, G., Zingone, A. & Frada, M. J. (2021). Novel heterococcolithophores, holococcolithophores and life cycle combinations from the families Syracosphaeraceae and Papposphaeraceae and the genus Florisphaera. Journal of Micropalaeontology. 40: 75-99. gs O

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

Malinverno, E., Leoni , B. & Galli, P. (2022). Coccolithophore assemblages and a new species of Alisphaera from the Faafu Atoll, Maldives, Indian Ocean. Marine Micropaleontology. 172(102110): 1-16. gs

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

Calcidiscus leptoporus subsp. quadriperforatus HOL

References:

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