Nannotax3 - ntax_cenozoic - Syracosphaera borealis Nannotax3 - ntax_cenozoic - Syracosphaera borealis

Syracosphaera borealis

Classification: ntax_cenozoic -> Syracosphaerales -> Syracosphaeraceae -> Syracosphaera -> SY molischii gp -> borealis type -> Syracosphaera borealis
Sister taxa: S. borealis, S. strigilis, S. pemmadiscus, S. andruleitii


Citation: Syracosphaera borealis Okada & McIntyre, 1977
taxonomic rank: Species
Taxonomic discussion: Young et al. 2003 recognised two variants within S. borealis - type 1 and type 2, the type 2 variant is now regarded as a separate species, S. strigils (formerly S. hirsuta)

Distinguishing features:
Parent taxon (borealis type): XCs elliptical discs, with a narrow rim, central part without conical depression. CFCs not differentiated.
This taxon: BCs with smooth rim - axial structure prominent irregular ridge or ring; XCs smooth eliptical discs, rare

Farinacci & Howe catalog pages: S. borealis *


BCs - distal flange moderately broad, slightly flaring, with low sutural ridges; axial structure - irregular ridge or cluster of nodes formed by upgrowth from laths. Sutures radial or with slight dextral obliquity. 
XCs - small, folded into saddle-shape; rim, narrow, symmetrical (no wing development). Usually only a few observed or absent. Can show arcuate openings at the ends of the central area but these are often not present, or possibly obscured by organics.

Coccospheres 6-8 µm /BCs 1.5-2.5 µm

Ecology & Biogeography

A common sub-Arctic species

Biology & life-cycles
No direct observations, but the very similar species S. strigilis has a known holococcolith stage

Search data:
LITHS: murolith, placolith, elliptical, CA: ca_disjunct, grill, plate,
CSPH: equant, XC, CROSS-POLARS: R-prominent, T-prominent,
Lith size: 1.5->3µm; Coccosphere size: 8->10µm; Liths per sphere: 30->50
Data source notes: csph & lith length (BCs) from OD & illustrated specimens; lith numbers from Yang & Wei 2003, range of estimates
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 No known fossil record modern (0-0Ma, base in "Holocene" stage). Data source: [JRY rough estimate]

Plot of occurrence data:


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

Meier, K. J. S., Kinkel, H. & Young, J. R. (2014). A note on calcareous nannoplankton from the Kieler Förde (Baltic Sea). Journal of Nannoplankton Research. 33(1): 29-37. gs

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

Samtleben, C. et al. (1995). Plankton in the Norwegian-Greenland Sea: from living communities to sediment assemblages - an actualistic approach. Geologische Rundschau. 84: 108-136. gs

Thomsen, H. A. (2016). Baltic Sea coccolithophores – an overview of insights into their taxonomy and ecology from the last 40 years. Journal of Nannoplankton Research. 36(2): 97-119. gs 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. S1: 1-132. gs


Syracosphaera borealis compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-12-2023

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