Nannotax3 - ntax_cenozoic - Sphenolithus calyculus

Sphenolithus calyculus

Classification: ntax_cenozoic -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. heteromorphus group -> Sphenolithus calyculus
Sister taxa: S. heteromorphus, S. milanetti, S. preasii ⟩⟨ S. pseudoheteromorphus, S. conicus, S. calyculus


Citation: Sphenolithus calyculus Bukry, 1985
Rank: Species

Taxonomic discussion:
One of the Late Oligocene Early Miocene group of delicate sphenoliths (see also S. capricornutus, S. delphix). Characterised by a single long apical spine, and a compact base, in contrast to the flaring base of S. delphix. It is smaller and thinner than S. heteromorphus.

Distinguishing features:
Parent taxon (S. heteromorphus group): Late Oligocene - Early Miocene sphenoliths with apical spines formed from a single element.
This taxon: Small sphenolith with long apical spine and compact base.

Farinacci & Howe catalog pages: S. calyculus * , S. elongatus Martini *

Most likely ancestor: Sphenolithus conicus - at confidence level 3 (out of 5). Data source: Howe 2021 fig8.
Likely descendants: Sphenolithus pseudoheteromorphus; plot with descendants

Search data:
TagsLITHS: nannolith-radiate, circular, cylindrical, CA: process, CROSS-POLARS: V-prominent, R-prominent,
MetricsLith size: 5->9µm;
Data source notes: lith height from ODs
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within NN2 zone (19.00-22.82Ma, top in Burdigalian stage). Data source: Bergen et al. 2017
First occurrence (base): within NP25 zone (24.40-26.84Ma, base in Chattian stage). Data source: Young 1998; Bergen et al. 2017

Plot of occurrence data:


Bergen, J. A., de Kaenel, E., Blair, S. A., Boesiger, T. M. & Browning, E. (2017). Oligocene-Pliocene taxonomy and stratigraphy of the genus Sphenolithus in the circum North Atlantic Basin: Gulf of Mexico and ODP Leg 154. Journal of Nannoplankton Research. 37(2-3): 77-112. gs V O

Bown, P. R. & Dunkley Jones, T. (2012). Calcareous nannofossils from the Paleogene equatorial Pacific (IODP Expedition 320 Sites U1331-1334). Journal of Nannoplankton Research. 32(2): 3-51. gs V O

Bukry, D. (1985). Mid-Atlantic Ridge coccolith and silicoflagellate biostratigraphy, Deep Sea Drilling Project Sites 558 and 563. Initial Reports of the Deep Sea Drilling Project. 82: 591-603. gs V O

de Kaenel, E. & Villa, G. (1996). Oligocene-Miocene calcareous nannofossil biostratigraphy and paleoeecology from the Iberian Abyssal Plain. Proceedings of the Ocean Drilling Program, Scientific Results. 149: 79-145. gs V O

Howe, R. (2021). Ultrastructure and taxonomy of the family Sphenolithaceae. Journal of Nannoplankton Research. 39(1): 29-75. gs

Martini, E. (1986). Paleogene calcareous nannoplankton from the southwest Pacific Ocean, Deep Sea Drilling Project, Leg 90. Initial Reports of the Deep Sea Drilling Project. 90: 747-761. gs V O

Perch-Nielsen, K. (1980a). New Tertiary calcareous nannofossils from the South Atlantic. Eclogae Geologicae Helvetiae. 73(1): 1-7. gs V O

Young, J. R. (1998). Neogene. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 225-265. gs V O


Sphenolithus calyculus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 21-9-2021

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