Nannotax3 - ntax_main - Grantarhabdus Nannotax3 - ntax_main - Grantarhabdus

Grantarhabdus


Classification: ntax_main -> Mesozoic nannofossils -> Podorhabdales -> Cretarhabdaceae -> Grantarhabdus
Sister taxa: Mattiolia, Wisea ⟩⟨ Speetonia ⟩⟨ Cruciellipsis, Flabellites, Grantarhabdus, Helenea ⟩⟨ Cretarhabdus, Retecapsa, Pickelhaube, Miravetesina

Daughter taxa (time control age-window is: 0-800Ma)
Grantarhabdus camaratus
Large (ca 8-10 µm) cretarhabdid with diagonal cross and space in between crossbars filled by perforate net.
Grantarhabdus coronadventis
Medium to large( 6-12 µm) cretarhabdid with diagonal cross.
Grantarhabdus meddii
Medium to large( 7-10 µm) cretarhabdid; central area wide with diagonal cross - crossbars at low angle and meet to form a solid bar for about half their length.
Grantarhabdus sp.
Specimens not identified to species level

Taxonomy:
Citation: Grantarhabdus Black, 1971
Taxonomic rank: genus
Type species: Grantarhabdus meddii Black, 1971
Synonyms: Gephyrorhabdus Hill, 1976 (type species G. coronadventis)

Distinguishing features:
Parent taxon (Cretarhabdaceae): Regular placoliths; central-area spanned by elevated distal structure typically with cross bars and central spine.
The distal shield usuallyappers to be weakly bicyclic in the SEM, with a narrow outer-cycle and broad inner-cycle; elements usually radial and non-imbricate. LM image is moderately birefringent. V/R structure unclear.

This taxon: Cretarhabdids with relatively narrow shields; central area wide with diagonal cross bars.

Farinacci & Howe catalog pages:
Grantarhabdus + * , Gephyrorhabdus *

Search data:
LITHS: placolith, elliptical, CA: ca_disjunct, process, diagonal cross, CROSS-POLARS: rim-unicyclic, R-prominent,
Lith size: 0->0µm;
Data source notes: size range of included species
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): at top of Campanian Stage (100% up, 72.2Ma, in Campanian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within Late Tithonian Substage (143.10-145.00Ma, base in Tithonian stage). Data source: Total of ranges of species in this database

Plot of occurrence data:

References:

Black, M. (1971a). Coccoliths of the Speeton Clay and Sutterby Marl. Proceedings of the Yorkshire Geological Society. 38: 381-424. gs

Bown, P. R. & Young, J. R. (1997). Mesozoic calcareous nannoplankton classification. Journal of Nannoplankton Research. 19(1): 21-36. gs

Bown, P. R., Rutledge, D. C., Crux, J. A. & Gallagher, L. T. (1998). Lower Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series . 86-131. gs O

Hill, M. E. (1976). Lower Cretaceous calcareous nannofossils from Texas and Oklahoma. Palaeontographica Abteilung B Palaeophytologie. 156: 103-179. gs


nannotaxlogo400px

Grantarhabdus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 14-2-2026

Taxon Search:
Advanced Search

Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10485 Go to Archive.is to create a permanent copy of this page - citation notes



Add Comment

* Required information
Captcha Image

Comments

No comments yet. Be the first!