Nannotax3 - ntax_mesozoic - Stephanolithion

Stephanolithion

Classification: ntax_mesozoic -> Stephanolithiales -> Stephanolithiaceae -> Stephanolithion
Sister taxa: Cylindralithus, Darwinilithus, Rotelapillus, Stephanolithion, Stoverius, Stradnerlithus ⟩⟨ Corollithion, Rhombolithion, Truncatoscaphus ⟩⟨ Paralithella, Rectocorona, Thurmannolithion

Distinguishing features: Elliptical and often polygonal; rims low but broad, bicyclic; central-area spanned by one to eight bars; prominent spines protrude from the rim

Daughter taxa (time control age-window is: 0-800Ma)		Granddaughter taxa
	Stephanolithion atmetos Narrowly elliptical, near-parallel sided, with transverse bar
	Stephanolithion bigotii Broadly elliptical or hexagonal, with long rim spines, and diagonal cross bars.	S. bigotii subsp. bigotii S. bigotii subsp. maximum
	Stephanolithion brevispinus Elliptical, with very short rim spines, and diagonal cross bars.
	Stephanolithion hexum Elliptical, with multiple rim spines and six cross bars.
	Stephanolithion speciosum Elliptical with multiple short rim spines and eight cross bars.
	Stephanolithion sp. Specimens not identified to species level

Taxonomy:

Citation: Stephanolithion Deflandre, 1939

Rank: Genus

Type species: Stephanolithion bigotii Deflandre, 1939

Synonyms:

Paractinozygus Cooper 1987 [my interpretation - JRY 2021]

Farinacci & Howe catalog pages: Stephanolithion * , Paractinozygus + *

Distinguishing features: Elliptical and often polygonal; rims low but broad, bicyclic; central-area spanned by one to eight bars; prominent spines protrude from the rim

Morphology: Elliptical and often polygonal murolith (protolith) coccoliths with spines that protrude from the rim. The rims are low but relatively broad, have weakly-developed proximal/inner-cycles, and a central-area spanned by one to eight bars, supporting a central spine. LM image is usually bicyclic but the outer dark cycle of V-units is better developed than the inner cycle of R-units and the central structure non-birefringent, so they are best viewed in phase contrast. The rim spines are formed by outwrd growth of single V-units from the rim.

Search data:

Tags	LITHS: murolith, elliptical, CA: ca_disjunct, process, diagonal cross, CROSS-POLARS: rim-bicyclic, V-prominent,
Metrics	Lith size: 4->9µm; Data source notes: size range of included species

The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): in mid part of Tithonian Stage (53% up, 148.3Ma, in Tithonian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Bajocian Stage (31% up, 169.7Ma, in Bajocian stage). Data source: Total of range of species in this database

Plot of occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Stephanolithiaceae

References:

Bown, P. R. & Cooper, M. K. E. (1998). Jurassic. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 34-85. gs

Deflandre, G. (1939). Les stéphanolithes, représentants d'un type nouveau de coccolithes Jurassique supérieur. Comptes Rendus Hebdomadaires des Séances de l'Académie des Sciences, Paris. 208: 1331-1333. gs V O

Missing or ambiguous references: Cooper 1987;