Nannotax3 - ntax_cenozoic - S. moriformis group

S. moriformis group


Classification: ntax_cenozoic -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. moriformis group
Sister taxa: S. moriformis group ⟩⟨ S. heteromorphus group, S. delphix group, S. capricornutus group, S. dissimilis group ⟩⟨ S. furcatolithoides group, S. radians group, S. anarrhopus group, S. sp.

Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Sphenolithus abies
Moderately elevated sphenolith with cuspate outline and with extinction line going down long axis of spine.
S. bergenii
S. neoabies
S. quadrispinatus
S. verensis

Sphenolithus apoxis
Conical sphenolith with a compound apical spine. (like S. abies but older)

Sphenolithus moriformis
Beehive shaped sphenolith, apical elements not in extinction in vertical position. No spine, upper and lower parts of similar size.

Large species
Sphenolithus grandis
Large (>10 µm) beehive shaped sphenoliths (Mid-Late Miocene)

Sphenolithus puniceus
Hemispherical, like S. moriformis but larger (7-11 µm) and therefore more birefringent (Oligocene - Early miocene)

Sphenolithus acervus
Large (>8.0µm) globular, coarsely-constructed sphenolith without a spine. (Palaeocene - Early Eocene)

Ancestral species
Sphenolithus primus
Small with dome-shaped opening on proximal side

Taxonomy:

Citation: Sphenolithus moriformis group
Rank: species group
Synonyms:

Taxonomic discussion:
This group was recognised, with broadly the same content, by Bown & Dunkley Jones 2006, Bergen et al. 2017 and Howe 2021. Howe (2021) changed the name to S. primus group, since this is the ancestral species. We retain the established name here, since we prefer to name groups after abundant and universally accepted, species.

Species in this group are mostly poorly defined and of limited biostratigraphic value. Many workers only S. moriformis &/or S. abies.

Distinguishing features:
Parent taxon (Sphenolithus): Conical nannoliths with a concave base, consisting of a mass of elements radiating from a common origin.
This taxon: Conical and hemispherical sphenoliths without prominent apical spines.

Farinacci & Howe catalog pages:


Morphology:

Search data:
TagsLITHS:
MetricsLith size: 3->12µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): near base of Piacenzian Stage (14% up, 3.5Ma, in Piacenzian stage). Data source: Total of range of species in this database
First occurrence (base): near top of Danian Stage (90% up, 62.1Ma, in Danian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

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. (2006). New Paleogene calcareous nannofossil taxa from coastal Tanzania: Tanzania Drilling Project Sites 11 to 14. Journal of Nannoplankton Research. 28(1): 17-34. gs V O

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

Perch-Nielsen, K. (1985a). Cenozoic calcareous nannofossils. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. Cambridge University Press, Cambridge 427-555. gs


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S. moriformis group compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-9-2021

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=1215 Go to Archive.is to create a permanent copy of this page - citation notes



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