Mitrolithus


Classification: Mesozoic -> Stephanolithiales -> Parhabdolithaceae -> Mitrolithus
Sister taxa: Bucanthus, Calcivascularis, Crucirhabdus, Diductius, Mitrolithus, Parhabdolithus, Timorella, Umbria,

Distinguishing features: 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: (blue => in age window 0-800Ma)
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 with a spine that fits neatly into the rim forming a flush, domed upper surface.
Specimens not identified to species level

Taxonomy:

Citation: Mitrolithus Deflandre in Deflandre & Fert, 1954
Rank: Genus
Type species: Mitrolithus elegans Deflandre in Deflandre and Fert, 1954
Synonyms: Alvearium Black 1967

Farinacci & Howe catalog pages: Mitrolithus * , Alvearium *

Distinguishing features: 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 remarks: Protolith coccoliths with high rim and broad proximal/inner rim cycle on which sits a massive boss/spine. Bicyclic rim image in XPL, but often seen in side view revealing the distinctive spines.

Geological Range:
Last occurrence (top): in upper part of Toarcian Stage (74% up, 176.4Ma, in Toarcian stage). Data source: Total of range of species in this database
First occurrence (base): near top of Hettangian Stage (92% up, 199.5Ma, in Hettangian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

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

Deflandre, G. & Fert, C. (1954). Observations sur les coccolithophoridés actuels et fossiles en microscopie ordinaire et électronique. Annales de Paléontologie. 40: 115-176. gs


nannotaxlogo400px

Mitrolithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 20-9-2019

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10692 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet. Be the first!

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics