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Costellagerina pilula


Classification: pf_mesozoic -> Hedbergellidae -> Costellagerina -> Costellagerina pilula
Sister taxa: C. bulbosa, C. pilula, C. sp.,

Taxonomy

Citation: Costellagerina pilula (Belford, 1960)
Rank: Species
Basionym: Rugoglobigerina pilula
Synonyms: Rugoglobigerina (Rugoglobigerina) plana

Type images:

Original description: Rugoglobigerina pilula Belford 1960:

Diagnosis: Test trochoid, chambers globular, inflated, arranged in a high spire, 5-6 in last whorl. Sutures depressed, surface of test ornamented with small ridges, on some chambers in a meridional pattern. Aperture interiomarginal umbilical, large.

Description: Test trochoid, both dextrally and sinistrally coiledforms known, with the latter the more common; umbilicus small, circular, usually infilled. Test trochoid, both dextrally and sinistrally coiled forms occurring, with the latter the more common; umbilicus small, circular, usually infilled. chambers globular, strongly inflated, forming two and one-half to three whorls, each whorl only partly overlapping the one preceding, forming a high sire; five or six chambers in last whorl, increasing slowly in size as added. Sutures straight or slightly curved on spiral side, straight on umbilical side, depressed on both sides. Test ornamented with small discontinuous ridges, irregularly arranged on early chambers and forming a meridional pattern on chambers of last whorl, the last one or two chambers may be smooth. Wall of test calcareous, finely perforate, radiate in structure. Aperture interiomarginal umbilical, large and arcuate, not often observed because of infilling umbilicus; only remnants of tegilla have been observed.

Entries in the Catalog of original descriptions: Rugoglobigerina (Rugoglobigerina) plana;
Rugoglobigerina pilula;

Geological Range:
Last occurrence (top): within G. elevata zone (79.20-84.19Ma, top in Campanian stage). Data source: [copied from Chronos database]
First occurrence (base): within D. asymetrica zone (84.19-86.71Ma, base in Coniacian stage). Data source: [copied from Chronos database]

Plot of occurrence data:

Dec 2017 - Plotting of Neptune data has been re-enabled on the Mesozoic pages following revision of the age-models in Neptune. The data is, however, still very sparse for the Early Cretaceous

Character matrix

test outline:Subcircularchamber arrangement:Trochospiraledge view:Concavo-convexaperture:Interiomarginal
umb chamber shape:Inflatedcoiling axis:Highperiphery:aperture border:
sp chbr shape:Inflatedumbilicus:Wideperiph margin shape:Broadly roundedaccessory apertures:None
umbilical or test sutures:Strongly depressedumb depth:Deepwall texture:Meridional costellaeshell porosity:
spiral sutures:Strongly depresseddiameter mm:0.33 mm to 0.36 mmwidth mm:0.21 to 0.23breadth mm:
final-whorl chambers:5.0-6.0

References:

Belford, D.J., (1960). Upper Cretaceous foraminifera from the Toolonga Calcilutite and Gingin Chalk, Western Australia. Australia Bureau of Mineral Resources, Geology and Geophysics Bulletin, 57: 1-198.


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Costellagerina pilula compiled by the pforams@mikrotax project team viewed: 21-2-2018

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Comments (1)

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PALEOSEDES (Bogota, Colombia)

Costellagerina

Rugoglobigerina pilula Belford, 1960

Today: Costellagerina pilula (Belford, 1960)AUTOR, YEAR? pleasse

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Jeremy Young (UK)

Fair question. Unfortunately, however, under the ICZN (unlike the ICN/ICBN) the authorship of combinations is not formally recorded, so it is difficult to database or record them and we do not attempt to do so comprehensively on mikrotax. In this case I strongly suspect that the combination was proposed in Petters et al. 1983, but I don't have a copy to hand to check this.

Petters, S.W.; El-Nakhal, H.A. & Cifelli, R., (1983). Costellagerina, a new late Cretaceous Globigerine foraminiferal genus. Journal of Foraminiferal Research, 13(4): 247-251.)

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