Catalog - Blefuscuiana daminiae Catalog - Blefuscuiana daminiae

CATALOG OF ORIGINAL DESCRIPTIONS: Blefuscuiana daminiae Banner, Copestake, & White 1993

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.

Higher levels: pf_cat -> B -> Blefuscuiana -> Blefuscuiana daminiae
Other pages this level: B. albiana, B. aptiana depressa, B. aptiana implana, B. aptiana orientalis, B. daminiae, B. excelsa cumulus, B. globigerinellinoides lobulata, B. hexacamerata, B. kuznetsovae, B. laculata, B. laculata alobata, B. laculata laculata, B. mitra, B. multicamerata, B. occulta perforocculta, B. occulta quinquecamerata, B. praesimilis, B. rudis, B. speetonensis, B. speetonensis tunisiensis, B. whittakeri

Blefuscuiana daminiae

Citation: Blefuscuiana daminiae Banner, Copestake, & White 1993
taxonomic rank: Species
Type specimens: P52696
Type sample (& lithostrat): Uppermost Valhall Formation
Type age (chronostrat): Early Aptian.
Type locality: Holotype. P52696 (PI. 3, figs. 6a-c), from North Sea Well 15/30-3, 12830-12840 ft, Early Aptian. Paratypes. P52699 (PI. 4, fig. 3), from same sample as halo- type. P52697, from North Sea Well 16/28-6RE, 4150.5 m, Early Aptian. P52698 and P52700, both from North Sea Well 20/2- 2, Early Aptian, from 8300 ft (PI. 4, figs. la- c) and 8250 ft respective!y.
Type repository: London, UK; NHM

Linked specimens: London, UK; NHM (PM PF 52696)

Current identification/main database link: Blefuscuiana daminiae Banner, Copestake, & White 1993

Original Description

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.

After Damini Desai, who took some initial SEM photographs and helped begin this phase of the study.

Extra details from original publication
REMARKS This species most closely resembles B. infracretacea aptica but differs in having only part of the first chamber in the last whorl visible ventrally. B. daminiae therefore appears to be morphologically less evolved than B. infracretacea aptica. Since B. daminiae is known only from the Early Aptian, while B. infracretacea aptica has been found in beds 1 of Early to Late Aptian age (see below) it seems possible that B. daminiae may be the ancestral form. The much more rapid chamber enlargement in the last whorl of this species, as seen dorsally, easily distinguishes it from B. laculata s.l.. Although the holotype lacks perforation-cones and possesses a smooth surface, perforation-cones may be present on some specimens (e.g. PI. 4, fig. 3a); these may merit subspecific distinction, but further study has yet to be made.
DISTRIBUTION. Central North Sea (wells).


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. gs


Blefuscuiana daminiae compiled by the pforams@mikrotax project team viewed: 18-7-2024

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