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Blefuscuiana daminiae


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

Taxonomy

Citation: Blefuscuiana daminiae Banner, Copestake, & White 1993
Rank: Species
Basionym: Blefuscuiana daminiae

Type images:

Original description: Blefuscuiana daminiae Banner, Copestake, & White 1993: Characterised by having 5 chambers in the last whorl of which only part of the first is seen ventrally, thereby giving an overall subquadrangular appearance to the test and by a deep umbilicus, resulting from the distinct overhang of the chambers in the last whorl. Adult test about 0.20mm at its maximum diameter, comprising at least 2 whorls coiled in a low trochospire. There are 5 chambers in each of the penultimate and last whorls. The spiral side is slightly concave to slightly convex and the intercameral sutures are moderately depressed, forming intercameral angles of about 140-150 degrees at the periphery of the test. The chambers are symmetrical and increase gradually in size with growth. They are subglobular in the penultimate whorl and depressed to slightly depressed (about 1/2 - 2/3 as high as long, when viewed from the spiral side) in the last tum of the spire, with the first two chambers in the latter tending to be more depressed than the last three. The final chamber may be almost as high as long. The umbilicus is small and deep; the aperture appears to be a narrow slit.

Entries in the Catalog of original descriptions: Blefuscuiana daminiae;

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 Aptian Stage (112.95-126.30Ma, base in Aptian 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:Narrow
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:periph margin shape:Moderately rounded
umb depth:Deepdiameter mm:width mm:breadth mm:
final-whorl chambers:4.5-5.0

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 daminiae compiled by the pforams@mikrotax project team viewed: 30-5-2017

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