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. | |
![]() | Darwinilithus Cylindrical nannofossil with median flange, a flaring cone on one side and a circlet of flaring spines on the other | ||||
![]() | ![]() | ![]() | Rotelapillus Subcircular to circular; rim high, narrow, bicyclic; central area spanned by radial bars; Short spines protrude from the rim | ||
![]() | ![]() | ![]() | ![]() | Stephanolithion Elliptical and often polygonal; rims low but broad, bicyclic; central-area spanned by one to eight bars; prominent spines protrude from the rim | |
![]() | Stoverius Narrowly elliptical to circular; rim low, bicyclic; central area wide, spanned by cross bars. | ||||
![]() | ![]() | ![]() | 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. | S. helotatus S. primitus S. geometricus S. fractus S. bifurcatus S. langii S. tortuosus S. asymmetricus S. escovillensis S. fragilis S. callomonii S. comptus S. clatriatus S. wendleri S. haynesiae S. silvaradius S. sp. | |
Polygonal | |||||
![]() | ![]() | ![]() | Corollithion Polygonal, usually hexagonal; rim bicyclic; central area with 4-6 radial bars | C. completum C. exiguum C. karegae C. kennedyi C. signum C. covingtonii C. madagaskarensis C. perch-nielseniae C. sp. | |
![]() | ![]() | Rhombolithion Diamond-shaped; rim unicyclic (stradnerlithids). | |||
![]() | ![]() | ![]() | Truncatoscaphus Polygonal (subhexagonal), often elongate and narrow; muroliths with central area spanned by a longitudinal bar and 6 or more lateral bars. | ||
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 | |||||
Rectocorona Elliptical murolith with non-imbricate wall and low spine supported by complex central structure | |||||
![]() | Thurmannolithion Elliptical; rim narrow; central area with axial cross, numerous lateral bars and spine |
Taxonomy:
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:
Size:
Tags | LITHS: murolith, ca_disjunct, |
Metrics | Lith size: 0->0µm; |
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:
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 Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Early Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 86-131. gsReferences:
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Stephanolithiaceae compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-5-2022
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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