Nannotax3 - ntax_mesozoic - Zeugrhabdotus praesigmoides

Zeugrhabdotus praesigmoides

Classification: ntax_mesozoic -> Eiffellithales -> Chiastozygaceae -> Zeugrhabdotus -> Zeugrhabdotus praesigmoides
Sister taxa: Z. blowii, Z. burolletii, Z. burwellensis, 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. kerguelenensis, Z. large spine, Z. clubhousensis ⟩⟨ 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.

Burnett1998-6-02-29ab.jpg
Burnett 97 JNR Petra pl1-8.JPG
Lees 2007 pl08 03-04.jpg
Lees 2007 pl08 05-06.jpg
Lees 2007 pl08 07-9.jpg

Taxonomy:

Citation: Zeugrhabdotus praesigmoides Burnett, 1997

Rank: Species

Farinacci & Howe catalog pages: Z. praesigmoides *

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

Morphology: 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:

Tags	LITHS: murolith, ca_disjunct, process, bar, CROSS-POLARS: rim-bicyclic, V-prominent,
Metrics	Lith size: 5->9µm; Data source notes: 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:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Histogram - Neptune occurrence data from DSDP and ODP proceedings. Pale shading <50 samples in time bin. Interpret with caution & read these notes
Taxon plotted: Zeugrhabdotus praesigmoides, synonyms included - Tranolithus argos; Zeugrhabdotus praesigmoides;
See also 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 V O

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

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 V O

Zeugrhabdotus praesigmoides compiled by Jeremy R. Young, Paul R. Bown, Jacqueline A. Lees viewed: 24-1-2021

Taxon Search:

Advanced Search

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

Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information

1000

Notify me of new comments via email.

Remember my form inputs on this computer.