Podorhabdids with central area spanned by eight bars that delineate eight large perforations that run either side of the longitudinal axis.
Podorhabdid with 8 bars, bars do not parallel the axes.
Specimens not identified to species level
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:
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.
| Tags | LITHS: placolith, elliptical, CA: ca_disjunct, grill, pores, process, CROSS-POLARS: rim-bicyclic, V-prominent, |
| Metrics | Lith size: 5->8µm; Data source notes: size range of included species |
Geological Range:
Last occurrence (top): at top of Tithonian Stage (100% up, 145Ma, in Berriasian stage). Data source: Total of range of species in this database
First occurrence (base): in upper part of Bajocian Stage (81% up, 168.7Ma, in Bajocian stage). Data source: Total of range of species in this database
Plot of occurrence data:
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 Noël, D. (1965b). 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. gsReferences:
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Octopodorhabdus compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 28-11-2021
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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