S. moriformis group


Classification: ntax_cenozoic -> Discoasterales -> Sphenolithaceae -> Sphenolithus -> S. moriformis group
Sister taxa: S. capricornutus group, S. dissimilis group, S. moriformis group, S. heteromorphus group, S. predistentus group, S. furcatolithoides group, S. radians group, S. conspicuus group, S. sp.

Daughter taxa (time control age-window is: 0-800Ma)
Sphenolithus abies
Moderately elevated sphenolith with cuspate outline and with extinction line going down long axis of spine.
Sphenolithus apoxis
Conical sphenolith with a compound apical spine. (like S. abies but older)
Sphenolithus bipedis
Hemispherical with a flared proximal cycle and arcuate proximal surface
Sphenolithus neoabies
Like S. abies/moriformis but smaller, <4µm & base broad
Sphenolithus moriformis
Beehive shaped sphenolith, apical elements not in extinction in vertical position. No spine, upper and lower parts of similar size.
Sphenolithus puniceus
Hemispherical, like S. moriformis but larger (7-11 µm) and therefore more birefringent
Sphenolithus grandis
Large (>10 µm) beehive shaped sphenoliths
Eocene species
Sphenolithus acervus
Large (>8.0µm) globular, coarsely-constructed sphenolith without a spine.
Sphenolithus primus
Small with dome-shaped opening on proximal side

Taxonomy:

Citation: Sphenolithus moriformis group
Rank: species group
Taxonomic discussion: Species in this group are mostly poorly defined and of limited biostratigraphic value. Many workers only S. moriformis &/or S. abies.

Distinguishing features: Conical and hemispherical sphenoliths without prominent apical spines.

Farinacci & Howe catalog pages:

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:

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: 8-3-2021

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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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