Distinguishing features:
Parent taxon (Parhabdolithaceae): Murolith (protolith type) coccoliths with bicylic rims and central-areas spanned by an axial-cross or transverse bar bearing a broad, often long, spine.
This taxon: Protolith coccoliths with high rim with broad proximal/inner rim cycle; central area filled by a massive boss/spine. Often seen in side view
Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
![]() | ![]() | ![]() | Mitrolithus elegans Mitrolithus with steeply sloping, high rim with very wide inner cycle on which sits a lens-shaped spine. Bicyclic rim image in XPL with distinctive broad, bright inner cycle and no central opening. Often seen in side view revealing the distinctive lens-shaped spines. Detached spines are circular in plan view (described as Alvearium dorsetense Black, 1965). | |
![]() | ![]() | Mitrolithus lenticularis Mitrolithus with a spine that fits neatly into the rim forming a flush, domed upper surface. | ||
Mitrolithus sp. Specimens not identified to species level |
Taxonomy:
Farinacci & Howe catalog pages: Mitrolithus + * , Alvearium *
Distinguishing features:
Parent taxon (Parhabdolithaceae): Murolith (protolith type) coccoliths with bicylic rims and central-areas spanned by an axial-cross or transverse bar bearing a broad, often long, spine.
This taxon: Protolith coccoliths with high rim with broad proximal/inner rim cycle; central area filled by a massive boss/spine. Often seen in side view
Morphology:
LITHS: murolith, elliptical, cylindrical, CA: process, ca_disjunct, CROSS-POLARS: R-prominent, V-prominent, rim-bicyclic, |
Lith size: 4->7µm; Data source notes: size range of included species |
Geological Range:
Last occurrence (top): at top of NJT7b subzone (100% up, 180.4Ma, in Toarcian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NJ2a subzone (197.26-199.66Ma, base in Hettangian stage). Data source: Total of ranges of species in this database
Plot of occurrence data:
Black, M. (1967). New names for some coccolith taxa. Proceedings of the Geological Society of London. 1640: 139-145. 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. & Young, J. R. (1997). Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 21-36. gs Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gsReferences:
![]() |
Mitrolithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 18-2-2025
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10692 Go to Archive.is to create a permanent copy of this page - citation notes |
![]() |
This policy contains information about your privacy. By posting, you are declaring that you understand this policy:
This policy is subject to change at any time and without notice.
These terms and conditions contain rules about posting comments. By submitting a comment, you are declaring that you agree with these rules:
Failure to comply with these rules may result in being banned from submitting further comments.
These terms and conditions are subject to change at any time and without notice.
Comments