Zeugrhabdotus praesigmoides


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

Distinguishing features: Bicyclic, medium-large; bar complex; bright inner rim broadest where it meets bridge, very narrow tends of central area.


Taxonomy:

Citation: Zeugrhabdotus praesigmoides Burnett, 1997
Rank: Species

Farinacci & Howe catalog pages: Zeugrhabdotus praesigmoides *

Distinguishing features: Bicyclic, medium-large; bar complex; bright inner rim broadest where it meets bridge, very narrow tends of central area.


Morphology remarks: A medium-sized species of Zeugrhabdotus in which the inner cycle is bright, and opposite quadrants go into extinction together on rotation. A small, twisted bridge, composed of small blocks, spans the narrow, open central area.
This form is smaller, and the inner cycle is broader, than in Z. sigmoides. The inner cycle is distinctively birefringent and the bar has a sigmoidal appearance similar to that seen in Z. sigmoides but dissimilar to other species of Zeugrhabdotus.

Search data:
TagsLITHS: murolith, CA: process, bar, V-UNITS: V-prominent, DETAILS: ca_disjunct, rim-bicyclic,
MetricsLith size: 5->9µm;
Sources: illustrated specimens
The morphological data given here can be used on the advanced search page. See also these notes

Geological Range:
Last occurrence (top): within Maastrichtian Stage (66.04-72.05Ma, top in Maastrichtian stage). Data source: Burnett, 1997 (original description)
First occurrence (base): within Santonian Stage (83.64-86.26Ma, base in Santonian stage). Data source: Burnett, 1997 (original description)

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 praesigmoides, synonyms included - Tranolithus argos; Zeugrhabdotus praesigmoides;
  • space-time plot :: Samples map :: Parent: Zeugrhabdotus

    References:

    Burnett, J. A. (1997c). New species and new combinations of Cretaceous nannofossils and a note on the origin of Petrarhabdus (Deflandre) Wise & Wind. Journal of Nannoplankton Research. 19(2): 133-146. gs :: view :: open

    Burnett, J. A. (1998). Upper Cretaceous. In, Bown, P. R. (ed.) Calcareous Nannofossil Biostratigraphy. British Micropalaeontological Society Publication Series. 132-199. gs :: ::

    Lees, J. A. (2007). New and rarely reported calcareous nannofossils from the Late Cretaceous of coastal Tanzania: outcrop samples and Tanzania Drilling Project Sites 5, 9 and 15. Journal of Nannoplankton Research. 29(1): 39-65. gs :: view :: open


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    Zeugrhabdotus praesigmoides compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 7-6-2020

    Taxon Search:
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    Short stable page link: http://mikrotax.org/Nannotax3/index.php?id=11339 Go to Archive.is to create a permanent copy of this page - citation notes



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