Nannotax3 - ntax_mesozoic - Stephanolithiaceae

Stephanolithiaceae


Classification: ntax_mesozoic -> Stephanolithiales -> Stephanolithiaceae
Sister taxa: Parhabdolithaceae, Stephanolithiaceae

Distinguishing features:
Parent taxon (Stephanolithiales): Murolith coccoliths with a distal/outer cycle of non-imbricating elements, i.e., in side view, the sutures are vertical or near-vertical.
This taxon: Murolith (protolith type) coccoliths with rims of non-imbricate V-units and weakly-developed, or vestigial, proximal/inner-cycles (R-units), with central-areas spanned by one to numerous bars. 


Daughter taxa (time control age-window is: 0-800Ma)Granddaughter taxa
Cylindralithus
Circular or sub-circular with high, sculpted, wall; central-area vacant or with cross bars.
Cylindralithus biarcus
Cylindralithus coronatus
Cylindralithus sculptus
Cylindralithus serratus
Cylindralithus duplex
Cylindralithus oweinae
Cylindralithus flat-top
Cylindralithus nieliae
Cylindralithus sp.

Darwinilithus
Cylindrical nannofossil with median flange, a flaring cone on one side and a circlet of flaring spines on the other
Darwinilithus pentarhethum
Darwinilithus sp.

Rotelapillus
Subcircular to circular; rim high, narrow, bicyclic; central area spanned by radial bars; Short spines protrude from the rim
Rotelapillus pleoseptatus
Rotelapillus crenulatus
Rotelapillus munitus
Rotelapillus radians
Rotelapillus hexaradiatus
Rotelapillus applegatei
Rotelapillus msakyae
Rotelapillus sp.

Stephanolithion
Elliptical and often polygonal; rims low but broad, bicyclic; central-area spanned by one to eight bars; prominent spines protrude from the rim
Stephanolithion atmetos
Stephanolithion bigotii
Stephanolithion brevispinus
Stephanolithion hexum
Stephanolithion speciosum
Stephanolithion sp.

Stoverius
Narrowly elliptical to circular; rim low, bicyclic; central area wide, spanned by cross bars.
Stoverius achylosus
Stoverius acutus
Stoverius coangustatus
Stoverius protosignum
Stoverius sp.

Stradnerlithus
Elliptical to diamond-shaped; rims low, narrow, unicyclic; central-area spanned by bars, radiating from central node or a longitudinal bar, usually spine bearing; typically small fragile and inconspicuous in LM.

Polygonal
Corollithion
Polygonal, usually hexagonal; rim bicyclic; central area with 4-6 radial bars
Corollithion completum
Corollithion exiguum
Corollithion karegae
Corollithion kennedyi
Corollithion signum
Corollithion covingtonii
Corollithion madagaskarensis
Corollithion perch-nielseniae
Corollithion sp.

Rhombolithion
Diamond-shaped; rim unicyclic (stradnerlithids).
Rhombolithion minutum
Rhombolithion scutulatus
Rhombolithion rhombicum
Rhombolithion octocostatum
Rhombolithion horrellii
Rhombolithion rotatum
Rhombolithion duodecostatum
Rhombolithion sp.

Truncatoscaphus
Polygonal (subhexagonal), often elongate and narrow; muroliths with central area spanned by a longitudinal bar and 6 or more lateral bars.
Truncatoscaphus hexaporus
Truncatoscaphus octoporus
Truncatoscaphus pauciramosus
Truncatoscaphus intermedius
Truncatoscaphus delftensis
Truncatoscaphus macmillanii
Truncatoscaphus sp.

Complex central structure
Paralithella
Very small (<2 µm) elliptical stephanolithid; central area with bridge supporting a hollow spine and bars parallel to the long axis
Paralithella recta

Rectocorona
Elliptical murolith with non-imbricate wall and low spine supported by complex central structure
Rectocorona brachyrhabda
Rectocorona sp.

Thurmannolithion
Elliptical; rim narrow; central area with axial cross, numerous lateral bars and spine
Thurmannolithion clatratum
Thurmannolithion sp.

Taxonomy:

Citation: Stephanolithiaceae Black 1968
Rank: Family
Taxonomic discussion: The family as originally described by Black (1968) included only Stephanolithion. The concept of the family was broadened by Black (1973). 

Farinacci & Howe catalog pages: Stephanolithiaceae [no catalog entry yet]

Distinguishing features:
Parent taxon (Stephanolithiales): Murolith coccoliths with a distal/outer cycle of non-imbricating elements, i.e., in side view, the sutures are vertical or near-vertical.
This taxon: Murolith (protolith type) coccoliths with rims of non-imbricate V-units and weakly-developed, or vestigial, proximal/inner-cycles (R-units), with central-areas spanned by one to numerous bars. 


Morphology:

LM image is usually unicyclic and inconspicuous, although a number of genera do exhibit bicyclicity, e.g. Rotelapillus, Stephanolithion and Stoverius. Coccolith outlines may be polygonal.

Size:

Search data:
CA: murolith, ca_disjunct,
Lith size: 0->0µm;
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Maastrichtian Stage (100% up, 66Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Pliensbachian Stage (21% up, 189.1Ma, in Pliensbachian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Black, M. (1968). Taxonomic problems in the study of coccoliths. Palaeontology. 11: 793-813. gs V O

Black, M. (1973). British Lower Cretaceous Coccoliths. I-Gault Clay (Part 2). Palaeontographical Society Monograph. 127: 49-112. gs

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 O

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gs O


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Stephanolithiaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-10-2022

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=11144 Go to Archive.is to create a permanent copy of this page - citation notes



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