Nannotax3 - ntax_cenozoic - Syracosphaera mediterranea

Citation: Syracosphaera mediterranea Lohmann 1902

Type species: Syracosphaera mediterranea Lohmann 1902

Synonyms:

Syracosphaera pulchroides Halldal & Markali (1955) [according to Okada & McIntyre 1977, Heimdal 1993]
Syracosphaera tuberculata Kamptner (1937) [according to Okada & McIntyre 1977, Heimdal 1993]
Coronosphaera mediterranea (Lohmann 1902) Gaarder, in Gaarder & Heimdal, 1977 [according to Triantaphyllou et al. 2016 and Young et al. 2020]

Variants:

Coronosphaera binodata (Kamptner 1927) Gaarder in Gaarder & Heimdal, 1977 = Syracosphaera mediterranea var. binodata Kamptner 1927 - morphotype with the two plates in the central area enlarged into distinct nodes. This morphotype has been widely regarded as a discrete species but Triantaphyllou et al. (2016) note that it forms combination coccospheres with S. mediterranea type holococcoliths and that it intergrades with classic S. mediterranea. All the evidence suggests that it is a more heavily calcified variant of S. mediterranea rather than a discrete species.

Taxonomic discussion: As discussed by Triantaphyllou et al. (2016) and Young et al. (2020) the species S. mediterranea has proven life-cycle associations with several different holococcoliths. As a result the genus Coronosphaera Gaarder 1977 is now a junior synonym of both Zygosphaera Kamptner 1936 and Syracolithus Kemptner 1941 and so can no longer be used. So, we are reverting here to the combination Syracosphaera mediterranea.

Distinguishing features:
Parent taxon (SY mediterranea group): BCs muroliths with imbricate wall, bipartite axial structure. No XCs (formerly Coronosphaera)
This taxon: Typical form, medium sized; BCs 3-4 µm, coccospheres 12-20 µm

Coccospheres (sub-)spherical 12-20 µm.
BCs elliptical (3-4 µm); low central mound formed of two irregular elements joined by transverse suture. Inner rim cycle lower than outer, forming shelf inside the lith.
The wall thickens distally and in LM this is a distinctive feature easily seen on coccospheres. Also note that in coccosphere equatorial view the central-area/basal-part of the coccoliths shows opposite crystallographic orientation (c-axis perpendicular to cell surface) to the wall (c-axis parallel to cell surface).

Biology & life-cycles: Four different holococcolith morphotypes have now been shown to be associated with C. mediterranea.

Syracosphaera mediterranea HOL wettsteinii type [Calyptrolithina wettsteinii] - combination coccospheres figured in Kamptner (1941) and Cros et al. (2000). Also repeatedly observed on edge of NW European shelf (Young unpupl obs, McGrane 2007).
Syracosphaera mediterranea HOL gracillima type [Calyptrolithophora hasleana & gracillima] - combination coccospheres figured in Cortes & Bollmann (2002) and Triantaphyllou et al. (2016).
Syracosphaera mediterranea HOL hellenica type [Zygosphaera hellenica] - developed in culture isolate, Geisen et al. (2002.) Combination coccospheres figured in Triantaphyllou et al. (2016).
Syracosphaera mediterranea HOL marisrubri type - a previously undescribed form similar to Calcidiscus leptoporus subsp. quadriperforatus HOL, but larger, see Keuter et al. (2021).

The range of holococcolith morphologies developed suggests that C. mediterranea may comprise at least four species which cannot, yet, be differentiated on the basis of heterococcolith morphology (Geisen et al. 2002). NB Although the three first holococcolith types have been placed in different genera they have several common features, in particular they are all dimorphic with flat-topped BCs and zygolith CFCs. The fourth type, however, seems to be very different.

Geological Range:
Notes: Coronosphaera mediterranea has been documented from the Early Miocene of the Paratethys (Galovic & Young 2012), but there are surprisingly few other fossil records.
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:

Andruleit, H., Rogalla, U. & Staeger, S. (2005). Living coccolithophores recorded during the onset of upwelling conditions off Oman in the western Arabian Sea. Journal of Nannoplankton Research. 27(1): 1-14. gs V O

Cortés, M. Y. & Bollmann, J. (2002). A new combination coccosphere of the heterococcolith species Coronosphaera mediterranea and the holococcolith species Calyptrolithophora hasleana. European Journal of Phycology. 37: 145-146. gs V O

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

Cros, L., Kleijne, A., Zeltner, A., Billard, C. & Young, J. R. (2000b). New examples of holococcolith-heterococcolith combination coccospheres and their implications for coccolithophorid biology. In, Young, J. R., Thierstein, H. R. & Winter, A. (eds) Nannoplankton ecology and palaeocology, Proceedings of the INA7 conference, Puerto Rico, February 1998. Marine Micropaleontology. 39(1-4): 1-34. gs

Gaarder, K. R. & Heimdal, B. R. (1977). A revision of the genus Syracosphaera Lohmann (Coccolithineae). “Meteor” Forschungsergebnisse, Reihe D, Biologie. 24: 54-71. gs O

Galovic, I. & Young, J. R. (2012). Revised taxonomy of some Middle Miocene calcareous nannofossils in the Paratethys. Micropaleontology. 58(4): -. gs

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 V O

Halldal, P. & Markali, J. (1955). Electron microscope studies on coccolithophorids from the Norwegian Sea, the Gulf Stream and the Mediterranean. Avhandlinger utgitt av det Norske Videnskapsakademi i Oslo. Matematisk-Naturvidenskapelig Klasse. 1955(1): 1-30. gs

Heimdal, B. R. (1993). Modern Coccolithophorids. In, Tomas, C. R. (ed.) Marine Phytoplankton: A Guide to Naked Flagellates and Phytoplankton. Academic Press, London 147-243. gs

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

Kamptner, E. (1941). Die Coccolithineen der Südwestküste von Istrien. Annalen des Naturhistorischen Museums in Wien. 51: 54-149. gs O

Konno, S. & Jordan, R. W. (2006). Lagoon coccolithophorids from the Republic of Palau, NW Equatorial Pacific. Journal of Nannoplankton Research. 28(2): 95-110. gs O

Lohmann, H. (1902). Die Coccolithophoridae, eine Monographie der Coccolithen bildenden Flagellaten, zugleich ein Beitrag zur Kenntnis des Mittelmeerauftriebs. Archiv für Protistenkunde. 1: 89-165. gs O

McGrane, P. B. (2007). Extant coccolithophores in Irish shelf waters of the northeast Atlantic. PhD thesis, Galway University. 1-360. gs O

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

Skejic, S. et al. (2018). Coccolithophore diversity in open waters of the middle Adriatic Sea in pre- T and post-winter periods. Marine Micropaleontology. 143(1): 30-45. gs

Triantaphyllou, M. et al. (2016). Coccolithophore combination coccospheres from the NE Mediterranean Sea: new evidence and taxonomic revisions. Micropaleontology. 61 [2015](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., 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

Tags	LITHS: murolith, elliptical, CA: ca_disjunct, grill, plate, process, CSPH: equant, CFC, CROSS-POLARS: rim-unicyclic, V-prominent, R-prominent,
Metrics	Lith size: 3->4.5µm; Coccosphere size: 13->16µm; Liths per sphere: 35->80 Data source notes: RCC

Syracosphaera mediterranea

References:

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