Daughter taxa (time control age-window is: 0-800Ma)![]() | ||||
![]() | ![]() | ![]() | Hexadelus archus Hexagonal formed of 6 flat plates, each an eqiulateral triangle |
Taxonomy:
Distinguishing features: Thin nannoliths similar to Braarudosphaera but with 6 segments - usually occur as isolated segments
Farinacci & Howe catalog pages: Hexadelus
Morphology: Isolated segments are equilateral triangles or wedge shaped, with 60° interior angles (vs. 72° for pentalith segments)
Phylogenetic relations: 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.
Tags | LITHS: nannolith-radiate, polygonal, CROSS-POLARS: T-prominent, |
Metrics | Lith size: 3->7µm; Segments: 6->6; |
Geological Range:
Last occurrence (top): in lower part of Rupelian Stage (17% up, 32.9Ma, in Rupelian stage). Data source: Total of range of species in this database
First occurrence (base): in lower part of Priabonian Stage (20% up, 37Ma, in Priabonian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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. gs V O 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. gsReferences:
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Hexadelus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 27-2-2021
Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=711 Go to Archive.is to create a permanent copy of this page - citation notes |