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Specimens which cannot be assigned to established species
Taxonomy
Original description: The smooth- to rough-walled, calcareous hyaline test is trochospirally coiled. Its small early chambers are globular, inflated, and globigerine-like. The last few chambers are elongated and extend into a relatively small umbilicus. The aperture is rounded interiomarginal, and opens into the umbilicus. Short apertural flaps extend into the umbilicus but do not form an umbilical cover-plate. Family Globotruncanidae.
Entries in the Catalog of original descriptions: Hedbergella, Blefuscuiana, Lilliputianella
Distinguishing features:
Parent taxon (Hedbergellidae): Test trochospirally coiled, primary aperture interiomarginal, extraumbilical-umbilical, with prominent apertural lip, apertures of earlier chambers remain visible around the umbilical region; no sutural secondary apertures.
This taxon: Test trochospiral, wall finely perforate, outer wall weakly to densely covered with perforation cones or perforation ridges (coalescing perforation cones); umbilical and spiral sutures depressed, radial, straight to slightly curved; aperture an interiomarginal extraumbilical-umbilical arch with a thin imperforate rim, rarely with a narrow bordering lip.
Emended description: Huber and Leckie, 2011: Test wall finely perforate, outer wall weakly to densely covered with perforation cones or perforation ridges (coalescing perforation cones), never with an imperforate or keeled peripheral margin or with muricae and rarely with small, blunt pustules. Test small to relatively large in size, coiled in a low to moderately high trochospire with a rounded equatorial periphery, umbilicate; chambers globular to ovate, four to nine in the final whorl; umbilical and spiral sutures depressed, radial, straight to slightly curved; aperture an interiomarginal extraumbilical-umbilical arch with a thin imperforate rim or in rare cases a narrow bordering lip.
Geological Range:
Last occurrence (top): within Albian Stage (100.50-112.95Ma, top in Albian stage). Data source: Total of range of species in this database
First occurrence (base): within Valanginian Stage (133.88-139.39Ma, base in Valanginian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
Character matrix
| test outline: | - | chamber arrangement: | Trochospiral | edge view: | - | aperture: | - |
| sp chamber shape: | - | coiling axis: | - | periphery: | N/A | aperture border: | - |
| umb chbr shape: | - | umbilicus: | - | periph margin shape: | - | accessory apertures: | - |
| spiral sutures: | - | umb depth: | - | wall texture: | - | shell porosity: | - |
| umbilical or test sutures: | - | final-whorl chambers: | 4.0-9.0 | N.B. These characters are used for advanced search. N/A - not applicable | |||
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 V O Huber, B. T. & Leckie, R. M. (2011). Planktic foraminiferal species turnover across deep-sea Aptian/Albian boundary sections. Journal of Foraminiferal Research. 41: 53-95. gs Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gsReferences:
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Hedbergella compiled by the pforams@mikrotax project team viewed: 27-10-2021
Short stable page link: https://mikrotax.org/pforams/index.php?id=110234 Go to Archive.is to create a permanent copy of this page - citation notes |
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