pforams@mikrotax - Braunella

pforams@mikrotax - Braunella pforams@mikrotax - Braunella

Braunella

Classification: pf_mesozoic -> Heterohelicidae -> Braunella
Sister taxa: Heterohelix, Spiroplecta ⟩⟨ Braunella, Hendersonites, Huberella, Laeviheterohelix, Planoheterohelix, Protoheterohelix, Pseudoguembelina, Pseudotextularia ⟩⟨ Planoglobulina, Ventilabrella, Gublerina, Praegublerina, Sigalia, Racemiguembelina ⟩⟨ Lunatriella, Rectoguembelina, Zeauvigerina

Daughter taxa (time control age-window is: 0-800Ma)
			Braunella brauni
			Braunella punctulata
			Braunella sp. Specimens which cannot be assigned to established species

Taxonomy

Citation: Braunella Georgescu, 2007

taxonomic rank: Genus

Type species: Gümbelina punctulata Cushman, 1938

Taxonomic discussion: The distinct, irregular reticulation of the test separates Braunella nov. gen. of the coeval Heterohelix s.l. species, the latter having dominant costate ornamentation, and from Pseudotextularia, which has pronounced, coarse costae. Occasional chamber proliferation in Braunella nov. gen. is developed between two rows of diverging chambers, whereas, by contrast, in Pseudotextularia-Racemiguembelina lineage the chambers of the proliferating stage are added in two planes resulting in a cone-shaped test. Pseudoguembelina Brönnimann & Brown presents secondary apertures along the zigzag suture as a result of chamber prolongation. By contrast, the supplementary apertures in Braunella are the result of the development of the periapertural structures. The ornamentation is different in Pseudoguembelina and Braunella, the former being completely costate and the latter presenting irregular reticulate ornamentation.

Original description: Diagnosis.– Test biserial, with subspherical chambers throughout. Chambers increase more or less regularly in size as added. Sutures distinct and depressed. Main aperture in the shape of a low- to medium-high arch, situated at the base of the last-formed chamber. Test ornamentation irregularly reticulate, at least in the earlier portion; chambers sometimes costate.
Description.– Test robust, biserial throughout. Chambers are subspherical, with the younger distinctly overlapping the previously formed ones. Chambers increase more or less regularly in size as added, resulting in highly variable shape of the test in lateral view. Chamber proliferation may occur occasionally in rare specimens. Sutures are distinct, depressed, and straight to slightly oblique to the axis of growth. Main aperture has the shape of a low to medium high arch, situated at the base of the last formed chamber of the test. It is bordered by two lateral, imperforate, rod-like rims, which are or are not attached to the penultimate chamber, and a wide imperforate band in the central part. Additional apertures can be developed along the zigzag suture if the rod-like rims are suspended. Test ornamentation is irregularly reticulate throughout. Costate ornamentation was observed on the last-formed chambers of some specimens. The test wall is calcareous, hyaline, finely perforate, the pores being situated in the spaces de- fined by the irregular reticulate network, or between the robust costae.

Entries in the Catalog of original descriptions: Braunella

Distinguishing features:
Parent taxon (Heterohelicidae): Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
This taxon: Biserial throughout, chambers globular, wall texture with irregular reticulate ornamentation

Morphology:

Test biserial, with subspherical chambers throughout. Chambers increase more or less regularly in size as added. Sutures distinct and depressed. Main aperture in the shape of a low- to medium-high arch, situated at the base of the last-formed chamber. Test ornamentation irregularly reticulate, at least in the earlier portion; chambers sometimes costate.

Geological Range:
Last occurrence (top): at top of P. hariaensis zone (100% up, 66.4Ma, in Maastrichtian stage). Data source: Total of ranges of the species in this database
First occurrence (base): within R. calcarata zone (75.06-75.91Ma, base in Campanian stage). Data source: Total of ranges of species in this database

Plot of range and occurrence data:

Range-bar - range as quoted above, pink interval top occurs in, green interval base occurs in.
Triangles indicate an event for which a precise placement has been suggested
Neptune data: This is a higher taxon page so Neptune data is not plotted. See also: customisable plot Parent: Heterohelicidae

References:

Georgescu, M. D. (2007b). Taxonomic re-evaluation of the Late Cretaceous serial planktonic foraminifer Gümbelina punctulata Cushman, 1938 and related species. Revista Española de Micropaleontología. 39: 1-14. gs