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Blefuscuiana laculata


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

Taxonomy

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

Type images:

Original description: Blefuscuiana laculata laculata Banner, Copestake, & White 1993: Diagnosis (sensu lato) [see also Blefuscuiana laculata subsp. alobata Banner, Copestake and White, 1993]. - Characterised by having 5 chambers in the last whorl, but with a test that is roughly quadrangular in outline, and by a broad, open umbilicus which the chambers do not overhang significantly. Test about 0.15-0.20mm at its maximum diameter, comprising at least two whorls of chambers coiled in a low trochospire. There are 4-5 chambers in the penultimate whorl and 5 chambers in the final whorl. The spiral side is almost flat to slightly concave. The chambers are symmetrical and increase in size gradually with growth. The chambers are subglobular in the penultimate whorl, and subglobular to slightly depressed (about 2/3 as high as long when viewed from the spiral side) in the final whorl. The umbilicus is broad, but the aperture is a narrow slit. No perforation cones are known. Diagnosis (sensu stricto). - Characterised by having a roughly quadrangular test outline, an open umbilicus, and intercameral sutures at the periphery of the test which form angles of about 120-135 degrees; the test surface lacks perforation cones.

Entries in the Catalog of original descriptions: Blefuscuiana laculata laculata;

Geological Range:
Last occurrence (top): within Barremian Stage (126.30-130.77Ma, top in Barremian 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:Subquadratecoiling axis:Lowchamber arrangement:Trochospiralumbilicus:
edge view:Concavo-convexumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:
wall texture:aperture:aperture border:accessory apertures:
periphery:umb chamber shape:sp chbr shape:Globularperiph margin shape:
umb depth:diameter mm:0.15-0.20width mm:breadth mm:
final-whorl chambers:4.5-5.5

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.


Blefuscuiana laculata compiled by the pforams@mikrotax project team viewed: 23-5-2017

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