Zeugrhabdotus howei


Classification: Mesozoic -> Eiffellithales -> Chiastozygaceae -> Zeugrhabdotus -> Zeugrhabdotus howei
Sister taxa: Z. acanthus, Z. angelozziae, Z. bicrescenticus, Z. biperforatus, Z. blowii, Z. burolletii, Z. burwellensis, Z. clarus, Z. cooperi, Z. diplogrammus, Z. elegans, Z. embergeri, Z. erectus, Z. fissus, Z. fluxus, Z. howei, Z. kerguelenensis, Z. moulladei, Z. noeliae, Z. petrizzoae, Z. praesigmoides, Z. reticulatus, Z. scutula, Z. sigmoides, Z. simplex, Z. sisyphus, Z. streetiae, Z. trivectis, Z. xenotus, Z. sp.,

Distinguishing features: Medium sized, unicyclic or diffusely bicyclic Zeugrhabdotus with a bar which has a characterstically birefringent, granular appearance when orientated parallel with the polarising directions. At 45° the bar becomes dark but bright protrusions (typically four) from the rim may be visible. In PC the darker, outer rim cycle dominates, but the bright protrusions are visible at the ends of the bar.


Taxonomy:

Citation: Zeugrhabdotus howei Bown in Kennedy et al., 2000
Rank: Species

Farinacci & Howe catalog pages: Zeugrhabdotus howei *

Distinguishing features: Medium sized, unicyclic or diffusely bicyclic Zeugrhabdotus with a bar which has a characterstically birefringent, granular appearance when orientated parallel with the polarising directions. At 45° the bar becomes dark but bright protrusions (typically four) from the rim may be visible. In PC the darker, outer rim cycle dominates, but the bright protrusions are visible at the ends of the bar.


Morphology remarks: The name Zeugrhabdotus elegans (Gartner, 1968 emend. Bukry, 1969) Burnett in Gale et al., 1996 has previouly been used to describe coccoliths with this morphology, but this species concept is poorly defined, and in any case is based upon a type specimen which is almost certainly Reinhardites anthophorus, and thus a junior synonym. Z. howei is a conspicuous component of many Albian and Cenomanian assemblages.

Geological Range:
Last occurrence (top): within Campanian Stage (72.05-83.64Ma, top in Campanian stage). Data source: Kennedy et al., 2000
First occurrence (base): within Early Barremian Substage (129.41-130.77Ma, base in Barremian stage). Data source: Kennedy et al., 2000

Plot of occurrence data:

  • Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
  • Note to users in China - the diagram may not plot unless you use a VPN since I use google services on the website. If this is a problem please contact me 谢谢.
  • Taxon plotted: Zeugrhabdotus howei, synonyms included - Zeugrhabdotus howei;
  • space-time plot :: Samples map :: Parent: Zeugrhabdotus

    References:

    Bown, P. R. (2001). Calcareous nannofossils of the Gault, Upper Greensand and Glauconitic Marl (Middle Albian-Lower Cenomanian) from the BGS Selborne boreholes, Hampshire. Proceedings of the Geologists' Association. 112: 223-236. gs

    Bown, P. R. (2005c). Early to Mid-Cretaceous Calcareous Nannoplankton from the Northwest Pacific Ocean, Leg 198, Shatsky Rise. Proceedings of the Ocean Drilling Program. Scientific Results. 198: 1-82. gs

    Kennedy, W. J. et al. (2000). Integrated stratigraphy across the Aptian-Albian boundary in the Marnes Bleues, at the Col de Pre _-Guittard, Arnayon (Drome), and at Tartonne (Alpes-de-Haute-Provence), France: a candidate Global Boundary Stratotype Section and Boundary Point for the base of the Albian Stage. Cretaceous Research. 21: 591-720. gs


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    Zeugrhabdotus howei compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 11-12-2019

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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11335 Go to Archive.is to create a permanent copy of this page - citation notes



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