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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:
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: Test broad and rounded, about 1½ 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, Pseudotextularia echevarriai, Heterohelix (Heterohelix) planeobtusa, Heterohelix robusta


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 range and occurrence data:

Character matrix

test outline:Subtriangularchamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:Inflatedcoiling axis:N/Aperiphery:N/Aaperture border:Thin flange
umb chbr shape:Inflatedumbilicus:N/Aperiph margin shape:Broadly roundedaccessory apertures:None
spiral sutures:Moderately depressedumb depth:N/Awall texture:Finely costateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:2.0-2.0 N.B. These characters are used for advanced search. N/A - not applicable

References:

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

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 V O

Nederbragt, A. J. (1991). Late Cretaceous biostratigraphy and development of Heterohelicidae (planktic foraminifera). Micropaleontology. 37: 329-372. gs

Pessagno, E. A. (1967). Upper Cretaceous planktonic foraminifera from the western Gulf Coastal Plain. Palaeontographica Americana. 5: 245-445. gs V O

Missing or ambiguous references: Georgescu 2007;


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Braunella punctulata compiled by the pforams@mikrotax project team viewed: 16-4-2021

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Short stable page link: https://mikrotax.org/pforams/index.php?id=110034 Go to Archive.is to create a permanent copy of this page - citation notes



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