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Braunella punctulata


Classification: pf_mesozoic -> Heterohelicidae -> Braunella -> Braunella punctulata
Sister taxa: B. brauni, B. punctulata, B. sp.,

Taxonomy

Citation: Braunella punctulata (Cushman, 1938)
Rank: Species
Basionym: Guembelina punctulata
Synonyms: Pseudotextularia echevarriai; Heterohelix planeobtusa; Heterohelix robusta
Taxonomic discussion: Multiserial chambers may occur. Georgescu. 2007, p.6: "The ESEM photographs of the holotype do not reveal that additional apertures along the zigzag suture as drawn by Pessagno (1967, pl. 86, figs. 9-10). To the contrary, it is the absence of additional apertures along the zigzag suture, together with the more regular increase in chamber size during the ontogeny that separates this species of Braunella brauni nov.gen., nov.sp." [copied from Chronos database]

Type images:

Original description: Guembelina punctulata Cushman 1938: "Test widely flaring in juvenile stage, sides subparallel in adult. Test broad and rounded, about 11 times as broad, initial portion rapidly tapering, later portion of nearly uniform width, periphery of early portion keeled, later indented; chambers of the early portion somewhat compressed, keeled, much broader than high, rapidly inflated in the adult where they are globular; sutures in the early portion slightly costate or with the fine perforations in vertical lines, in the adult thicker-walled with the surface rather coarsely punctate; aperture, a low, broad arch with a slight lip, the sides continuing in flange onto the preceding chamber."

Entries in the Catalog of original descriptions: Guembelina punctulata;
Heterohelix planeobtusa;
Heterohelix robusta;
Pseudotextularia echevarriai;


Emended description: Georgescu. 2007, p.6: "Test biserial throughout at most specimens, consisting of ten to seventeen chambers. Chamber proliferation may occur between the two rows of diverging chambers. Chambers are subspherical throughout, distinctly overlapping the previous ones these resulting in a slightly lobate test periphery in lateral view. They increase rapidly in size in the earlier part of the test but more slowly in the adult portion. Sutures are distinct, depressed, and straight to slightly oblique to the growth axis. Periphery broadly rounded, without peripheral structures such as rows of pustules, keels, etc. Aperture is situated at the base of the last formed chamber and is bordered by a wide, imperforate band. Test with irregularly reticulate ornamentation throughout; occasionally the last-formed chambers are longitudinally costate. Test wall is calcareous, hyaline, and finely perforate, pore diameter fluctuating between 1.3 and 2.4 microns. The size of the pores is dependent on the irregularly reticulate ornamentation and addition of successive layers of calcite during the ontogenetic growth." [copied from Chronos database]

Geological Range:
Last occurrence (top): within P. hariaensis zone (66.39-67.30Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within R. calcarata zone (75.71-76.18Ma, base in Campanian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

NB Plotting of Neptune data has been disabled on the Mesozoic pages because the dataset is both small and badly affected by a few sites with erroneous age models (our obs Huber, Petrizzo, Young, Nov 2016). The data can still be viewed via the range plottertool - tools menu.

Character matrix

test outline:Subtriangularcoiling axis:N/Achamber arrangement:Biserialumbilicus:N/A
edge view:Compressedumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:Finely Perforate: 1-2.5
wall texture:Finely costateaperture:Interiomarginalaperture border:Thin flangeaccessory apertures:None
periphery:N/Aumb chamber shape:Inflatedsp chbr shape:Inflatedperiph margin shape:Broadly rounded
umb depth:N/Adiameter mm:0.45-0.55width mm:0.22-0.25breadth mm:0.32-0.35
final-whorl chambers:2.0-2.0

References:

Cushman, J.A., (1938). Cretaceous species of Guembelina and related genera. Contributions from the Cushman Laboratory for Foraminiferal. Research, 14: 2-28.


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Braunella punctulata compiled by the pforams@mikrotax project team viewed: 22-7-2017

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