CATALOG OF ORIGINAL DESCRIPTIONS: Blefuscuiana albiana BouDagher-Fadel et al. 1996

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 albiana
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 albiana

Citation: Blefuscuiana albiana BouDagher-Fadel et al. 1996
Rank: Species
Type locality: Predoroshnaya, SW Crimea
Type age: Upper Albian
Holotype Repository: London, UK; NHM
Type & figured specimens: PF53012

Linked specimens: London, UK; NHM (53012)

Current identification/main database link: Microhedbergella albiana (Boudagher-Fadel et al., 1996)


Original Description
Test about 0.22-0.29 mm at its maximum diameter. This taxon comprises at least two whorls of subglobular chambers coiled in a low trochospire, and a slightly concave spiral side. It has five chambers in the last whorl. The chambers are high throughout the test. The wall is smooth; the microperforations of B. albiana are irregularly spaced and about 2 pm in diameter (twice as large as those of B. aptiana but half the size of those of true H edbergella - see BouDagher-Fadel et al., in press). The umbilicus is small (as in B. infracretacea), and is about 18 to 20% of the ventral test diameter. The apertu re is a narrow slit bordered by a thin porticus.



Later Redescrption (copied from Chronos webste): B. albiana has five subglobular chambers in the last whorl, which enlarge rapidly with growth, so that the addition of a new whorl increases the dorsal test diameter by almost twice. The umbilicus is small, as in B. infracretacea and is about 18 to 20% of the ventral test diameter. The aperture is slit-like with a thin porticus. The wall is smooth; the microperforations are irregularly spaced and are about 2 microns in diameter (twice as large as those of B. aptiana (Bartenstein) s.l. but about half the size as those of a true Hedbergella). There appears to be a slight but progressive increase in test size from B. aptiana (Bartenstein) s.s. (190-270 microns) and B. aptiana (Bartenstein) orientalis BouDagher-Fadel et al. (210-270 microns) in the Aptian to B. albiana (220-290 microns) in the Albian. It has already been suggested that B. albiana evolved from B. aptiana s.s. above the base of the Albian (BouDagher-Fadel et al., 1996).

Size: Test about 0.22-0.29 mm at its maximum diameter.

Extra details from original publication
B. albiana differs from B. aptiana sensu stricto in having high chambers throughout, and from B. aptiana occidentalis in lacking the perforation cones, and in having high chambers throughout and a slightly more concave dorsal side. B. aptiana and B. infracretacea, when viewed dorsally, increase their diameters by 60% to 70 % with the addition of a new whorl. However, B. albiana has a much greater rate of chamber enlargement, and the addition of a new whorl increases the dorsal test diameter by about 90 %. There appears to be a progressive slight increase in test size from B. aptiana sensu stricto (0.19-0.27 mm) and B. aptiana orientalis (0.21 -0.27 mm) in the Aptian to B. albiana (0.22-0.29 mm) in the Albian. On the other hand, there is enough overlap in the measurements of B. aptica and B. infracretacea to suggest that they are the same species (0.12-0.25 mm), but the mean of a population of B. albiana is somewhat larger.

Remarks: This form has often been cited in the literature as H. infracretacea. For example, GoRBACHIK & KRETCHMAR (1969) recorded it under this name from the Late Albian of the Crimea. It was also recorded by GoRBACHIK (1986), and our specimens come from the same material; they are from the Upper Albian (AP) of Predoroshnaya, close to Partisanskaya, SW Crimea. They are from the Hysteroceras orbignyi ammonite zone, and co-occur with Hedbergella globigerinelloides (SUBBOTINA) and Favusella washitensis (CARSEY). Further details of associated fauna and background can be found in GORBACHIK (1971), GORBACHIK & YANIN (1972) and NAlDlN (1987). Details of the ammonite zonation and foraminifcral zonation relevant to these sediments can be found in DRUSHTCHITZ & GORBACHlK (1979). Similar specimens were recorded in 1975 by MAGNIEZ-JANNIN (as H. infracretacea, in part) from the Middle Albian of the Aube in France. She believed this form to be ancestral to Ticinella primula LUTERBACHER of the Late Albian. B. albiana appears to be common in the Upper Albian in the north east of Alpine Tethys and in the Middle Albian to the north west of that region.

References:

BouDagher-Fadel, M. K., Banner, F. T., Gorbachik, T. N., Simmons, M. D. & Whittaker, J. E. (1996). Evolution in the Early Cretaceous planktonic foraminiferal genus Blefuscuiana. Neues Jahrbuch für Geologie und Palaeontologie Abhandlungen. 201(2): 243-258. gs


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Blefuscuiana albiana compiled by the pforams@mikrotax project team viewed: 10-12-2019

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