Nannotax3 - ntax_mesozoic - Octopodorhabdus Nannotax3 - ntax_mesozoic - Octopodorhabdus

Octopodorhabdus


Classification: ntax_mesozoic -> Podorhabdales -> Axopodorhabdaceae -> Octopodorhabdus
Sister taxa: Podorhabdus, Hemipodorhabdus, Axopodorhabdus, Tetrapodorhabdus, Hexapodorhabdus, Octocyclus, Octopodorhabdus ⟩⟨ Dodekapodorhabdus, Perissocyclus, Teichorhabdus ⟩⟨ Cribrosphaerella, Ethmorhabdus, Nephrolithus, Psyktosphaera ⟩⟨ Cribrocorona

Distinguishing features:
Parent taxon (Axopodorhabdaceae): Regular placoliths; central-area, with cross-bars or perforated plate; often with tall, hollow spines.
Distal shield elements non-imbricate V-units; proximal shield and inner cycle formed from R-units. Rim often appears beaded in LM

This taxon: Elliptical; central area spanned by eight bars that delineate eight large perforations. Central hollow spine.


Daughter taxa (time control age-window is: 0-800Ma)
Octopodorhabdus decussatus
Podorhabdids with central area spanned by eight bars that delineate eight large perforations that run either side of the longitudinal axis.
Octopodorhabdus praevisus
Podorhabdid with 8 bars, bars do not parallel the axes.
Octopodorhabdus sp.
Specimens not identified to species level

Taxonomy:

Citation: Octopodorhabdus Noël, 1965
taxonomic rank: Genus
Type species: Octopodorhabdus praevisus Noël, 1965.
Taxonomic discussion: Note that although Octocyclus and Octopodorhabdus are very similar (and have been regarded as synonyms by e.g. Verbeek 1977) they occur respectively in the Late Cretaceous and Jurassic, so it is unlikely that they are directly related. The type species of Octopodorhabdus (O.praevisus) is based on a very unsatisfactory sketch and is never cited. So it would probably be best to get rid of the genus and recombine the rather disparate species that remain in it.

Farinacci & Howe catalog pages: Octopodorhabdus + *

Distinguishing features:
Parent taxon (Axopodorhabdaceae): Regular placoliths; central-area, with cross-bars or perforated plate; often with tall, hollow spines.
Distal shield elements non-imbricate V-units; proximal shield and inner cycle formed from R-units. Rim often appears beaded in LM

This taxon: Elliptical; central area spanned by eight bars that delineate eight large perforations. Central hollow spine.


Morphology:

The type species, Octopodorhabdus praevisus Noël, 1965, is a sketch showing holes at either end of the central area. However, the commonly seen Jurassic form, Octopodorhabdus decussatus (Manivit, 1961) Rood et al., 1971 has holes either side of the central longitudinal bar.

Search data:
LITHS: placolith, elliptical, CA: ca_disjunct, grill, pores, process, CROSS-POLARS: rim-bicyclic, V-prominent,
Lith size: 5->8µm;
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 Tithonian Stage (100% up, 145Ma, in Berriasian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within NJ11 zone (166.4-168.67Ma, base in Bajocian stage). Data source: Total of ranges 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 O

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

Noël, D. (1965). Sur les Coccolithes du Jurassique Européen et d'Afrique du Nord. Essai de classification des coccolithes fossiles. Éditions du Centre National de la Recherche Scientifique, Paris. 1-209. gs


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Octopodorhabdus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 6-12-2023

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Short stable page link: https://mikrotax.org/Nannotax3/index.php?id=10815 Go to Archive.is to create a permanent copy of this page - citation notes
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