Taxonomy
Original description: 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
Character matrix
test outline: | - | chamber arrangement: | Trochospiral | edge view: | - | aperture: | - |
sp chamber shape: | - | coiling axis: | Low | periphery: | - | aperture border: | - |
umb chbr shape: | - | umbilicus: | - | periph margin shape: | - | accessory apertures: | - |
spiral sutures: | Moderately depressed | umb depth: | Shallow | wall texture: | - | shell porosity: | - |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 5-5.5 | N.B. These characters are used for advanced search. N/A - not applicable |
Geological Range:
Last occurrence (top): within Aptian Stage (113.20-121.40Ma, top in Aptian stage). Data source: [copied from Chronos database]
First occurrence (base): within Barremian Stage (121.40-126.50Ma, base in Barremian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
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. gsReferences:
Blefuscuiana depressa compiled by the pforams@mikrotax project team viewed: 8-9-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=110028 Go to Archive.is to create a permanent copy of this page - citation notes |
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