Hexadelus


Ancestry: Coccolithophores -> Braarudosphaerales -> Braarudosphaeraceae -> Hexadelus
Sister taxa: Braarudosphaera, Hexadelus, Micrantholithus, Pemma, Pentaster,

Short diagnosis: Thin nannoliths similar to Braarudosphaera but with 6 segments - usually occur as isolated segments


Daughter taxa (blue => in age window 0-300Ma)
Hexagonal formed of 6 flat plates, each an eqiulateral triangle

Taxonomy:

Citation: Hexadelus Shamrock & Watkins (2012)
Rank: Genus
Type species: Hexadelus archus Shamrock & Watkins 2012

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

Short diagnosis: Thin nannoliths similar to Braarudosphaera but with 6 segments - usually occur as isolated segments


Morphology remarks: Isolated segments are equilateral triangles or wedge shaped, with 60° interior angles (vs. 72° for pentalith segments)

Evolution & Phylogeny: Tentatively placed in the Braarudosphaeraceae here as they appear similar to pentaliths except for 6 fold symmetry but good observations are not available on crystallographic orientation or substructure.

Search data:
TagsLITHS: nannolith-radiate, hexagonal,
CSPH: not known, T-UNITS: all,
MetricsLith size: 3->7┬Ám; Segments: 6->6;
Sources:
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Rupelian Stage (28.09-33.89Ma, top in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): within Priabonian Stage (33.89-37.75Ma, base in Priabonian stage). Data source: Total of range of species in this database

Plot of occurrence data:

References:

Bown, P.R. & Dunkley Jones, T., (2006). New Paleogene calcareous nannofossil taxa from coastal Tanzania: Tanzania Drilling Project Sites 11 to 14. Journal of Nannoplankton Research, 28(1): 17-34.

Shamrock, J.L. & Watkins, D.K., (2012). Eocene calcareous nannofossil biostratigraphy and community structure from Exmouth Plateau, Eastern Indian Ocean (ODP Site 762). Stratigraphy, 9(1): 1-11.


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Hexadelus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 19-10-2017

Taxon Search:
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Go to Archive.is to create a permanent copy of this page - citation notes



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