nmn

Blefuscuiana depressa


Classification: pf_mesozoic -> Praehedbergellidae -> Blefuscuiana -> Blefuscuiana depressa
Sister taxa: B. alobata, B. cumulus, B. daminiae, B. depressa, B. implana, B. laculata, B. sp.,

Taxonomy

Citation: Blefuscuiana depressa (Banner, Copestake &White, 1993)
Rank: Species
Basionym: Blefuscuiana aptiana depressa depressa

Type images:

Original description: Blefuscuiana aptiana depressa depressa Banner, Copestake &White 1993: Test about 0.15-0.2mm at its maximum diameter, comprising about 2-3 whorls coiled in a low trochospire, each with 5-5.5 chambers. The spiral side is almost flat or slightly convex and the intercameral sutures are moderately depressed, forming angles of about 130-135 degrees at the periphery of the test. The chambers are symmetrical and increase in size gradually with growth, becoming depressed in the second and (when present) third whorl, being about half as high as long when viewed dorsally. The last chamber may be about as high as long. The umbilicus is 'open' and the aperture appears to be a narrow slit. The test surface lacks perforation cones.

Entries in the Catalog of original descriptions: Blefuscuiana aptiana depressa depressa;

Geological Range:
Last occurrence (top): within Aptian Stage (112.95-126.30Ma, top in Aptian stage). Data source: [copied from Chronos database]
First occurrence (base): within Barremian Stage (126.30-130.77Ma, base in Barremian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.

Character matrix

test outline:coiling axis:Lowchamber arrangement:Trochospiralumbilicus:
edge view:umbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:
wall texture:aperture:aperture border:accessory apertures:
periphery:umb chamber shape:sp chbr shape:periph margin shape:
umb depth:Shallowdiameter mm:width mm:breadth mm:
final-whorl chambers:5.0-5.5

References:

Banner, F.T.; Copestake, P. & White, M.R., (1993). Barremian-Aptian Praehedbergellidae of the North Sea area: a reconnaisance. Bulletin of the Natural History Museum, London (Geology), 49: 1-30.


logo

Blefuscuiana depressa compiled by the pforams@mikrotax project team viewed: 22-7-2017

Taxon Search:
Advanced Search

Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet. Be the first!

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics