Hexalithus


Classification: Mesozoic -> Braarudosphaerales -> Braarudosphaeraceae -> Hexalithus
Sister taxa: Braarudosphaera, Bukryaster, Hexalithus, Micrantholithus, Trapezopentus,

Distinguishing features: Six-rayed, stellate to hexagonal nannoliths.


Daughter taxa: (blue => in age window 0-800Ma)
Minute, subcircular nannolith with six elements.
Elements with lobate edges.
Elements with straight edges.
Specimens not identified to species level

Taxonomy:

Citation: Hexalithus Gardet, 1955
Rank: Genus
Type species: Hexalithus lecali Gardet, 1955.

Farinacci & Howe catalog pages: Hexalithus *

Distinguishing features: Six-rayed, stellate to hexagonal nannoliths.


Evolution & Phylogeny: Hexalithus appears in the Tithonian at about the same time as Nannoconus and Micrantholithus and it shows both tangential orientation and laminar substructure so it should be included within the Braarudosphaeraceae [my interpretation - JRY 2017] The species H. geometricus Casellato 2010 has been argued to be a junior synonym of Polycostella infans by Varol & Bowman (2019)

Geological Range:
Last occurrence (top): at top of Campanian Stage (100% up, 72.1Ma, in Campanian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Tithonian Stage (44% up, 149Ma, in Tithonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

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

Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs

Gardet, M. (1955). Contribution à l'étude des coccolithes des terrains néogènes de l'Algérie. Publications du Service de la Carte Géologique de l'Algérie (Nouvelle Série). 5: 477-550. gs


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Hexalithus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 5-12-2019

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Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=10524 Go to Archive.is to create a permanent copy of this page - citation notes



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