Taxonomy
Original description: The test is a low trochospire with five to six chambers in each of three whorls. The spiral side is evolute and flat; the chambers are normally subglobular, only the last one or two becoming radially subovoid and with increasingly depressed sutures. The intercameral sutures are subradial on both the spiral and umbilical sides. The umbilicus has a breadth equal to about 20% of the test diameter. The aperture is a low arch extending from the umbilicus to the periphery of the previous whorl and extending over it into the spiral suture in the last formed chamber; the aperture has a porticus extending from the umbilicus (where it is broadest) to the periphery but not beyond it. The surface of the test is smooth and microperforate (external perforations about 0.6 microns in diameter); a narrow imperforate zone may be present in the spiral suture where the aperture encroaches on to the spiral side.
Entries in the Catalog of original descriptions: Blefuscuiana mitra
Character matrix
test outline: | Lobate | chamber arrangement: | Trochospiral | edge view: | Spiroconvex | aperture: | |
sp chamber shape: | Globular | coiling axis: | Very low | periphery: | N/A | aperture border: | Thin lip |
umb chbr shape: | Globular | umbilicus: | Wide | periph margin shape: | Broadly rounded | accessory apertures: | Relict |
spiral sutures: | Moderately depressed | umb depth: | Shallow | wall texture: | Smooth | shell porosity: | Microperforate: <1µm |
umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 5-6 | N.B. These characters are used for advanced search. N/A - not applicable |
Geological Range:
Last occurrence (top): within L. cabri zone (119.05-120.55Ma, top in Aptian stage). Data source: [copied from Chronos database]
First occurrence (base): within L. cabri zone (119.05-120.55Ma, base in Aptian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Banner, F. T. & Desai, D. (1988). A review and revision of the Jurassic-Early Cretaceous Globigerinina,with especial reference to the Aptian assemblages of Speeton (North Yorkshire, England). Journal of Micropalaeontology. 7: 143-185. gs References:
Hedbergella mitra compiled by the pforams@mikrotax project team viewed: 10-12-2024
Short stable page link: https://mikrotax.org/pforams/index.php?id=110252 Go to Archive.is to create a permanent copy of this page - citation notes |
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