Nannotax3 - ntax_cenozoic - Sphenolithus microdelphix

Sphenolithus microdelphix

Classification: ntax_cenozoic -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. delphix group -> Sphenolithus microdelphix
Sister taxa: S. belemnos, S. tintinnabulum, S. bipedis, S. delphix, S. microdelphix, S. spinula


Citation: Sphenolithus microdelphix Bergen & de Kaenel, in Bergen et al. 2017
Rank: species

Distinguishing features:
Parent taxon (S. delphix group):
This taxon: Like S. delphix, but smaller (<8 µm)

Farinacci & Howe catalog pages: S. microdelphix *

Size: Specimen length is less than 8 µm. Length of ten measured specimens: 2.4–6.4 µm; width measured specimens: 2.4– 5.2 µm (holotype: 5.2 µm x 5.0 µm) [Bergen et al 2017]

Most likely ancestor: Sphenolithus spinula - at confidence level 3 (out of 5). Data source: Howe 2021, fig. 10.
Likely descendants: Sphenolithus delphix; plot with descendants

Search data:
TagsLITHS: nannolith-radiate, circular, cylindrical, CA: process, CROSS-POLARS: R-prominent,
MetricsLith size: 2.5->7µm;
Data source notes: Bergen et al 2017
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Notes: Bergen et al. (2017) record the FAd of S. microdelphix as occurring very close o that of S. delphix but the LAd signifcantly higher, within NN2
Last occurrence (top): in mid part of NN2 zone (50% up, 20.9Ma, in Aquitanian stage). Data source: Bergen et al 2017
First occurrence (base): in upper part of NP25 zone (70% up, 25.1Ma, in Chattian stage). Data source: 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

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


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

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Short stable page link: Go to to create a permanent copy of this page - citation notes

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