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Globigerinelloides bentonensis


Classification: pf_mesozoic -> Globigerinelloididae -> Globigerinelloides -> Globigerinelloides bentonensis
Sister taxa: G. algerianus, G. alvarezi, G. aptiensis, G. asper, G. barri, G. bentonensis, G. blowi, G. bollii, G. clavatus, G. duboisi, G. ehrenbergi, G. elongatus, G. escheri, G. ferreolensis, G. gottisi, G. impensus, G. lobatus, G. maridalensis, G. mendezensis, G. messinae, G. multispinus, G. paragottisi, G. praevolutus, G. prairiehillensis, G. pulchellus, G. saundersi, G. sigali, G. subcarinatus, G. ultramicrus,

Taxonomy

Citation: Globigerinelloides bentonensis (Morrow, 1934)
Rank: Species
Basionym: Anomalina bentonensis
Synonyms: Planomalina caseyi
Taxonomic discussion: Comparison of the SEM images of the holotypes of G. bentonensis and G. caseyi reveal that both species have a relatively smooth surface texture, a weakly lobate test outline, a moderately gradual rate of chamber size increase, and a low arched aperture at the base of the final chamber. Paratypes of G. caseyi have between 8 and 9 chambers in the final whorl, which overlaps the final whorl chamber number described for G. bentonensis. For this reason these species are considered synonymous with G. bentonensis designated as the senior synonym because of priority. [copied from Chronos database]

Type images:

Original description: Anomalina bentonensis Morrow 1934: "Test small, nearly symmetrical, slightly involute, periphery broadly rounded, earlier whorls partly exposed on both sides at the center; chambers inflated, increasng rather rapidly in size as added, quite uniform in shape, numbering 7-9 in last whorl; sutures strongly impressed, usually curving backward as they pass over the periphery; wall conspicuously perforated; aperture peripheral passing onto the dorsal side."

Entries in the Catalog of original descriptions: Anomalina bentonensis;
Planomalina caseyi;

Geological Range:
Last occurrence (top): within R. cushmani zone (94.03-95.94Ma, top in Cenomanian stage). Data source: [copied from Chronos database]
First occurrence (base): within T. primula zone (107.39-111.84Ma, base in Albian 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:Ellipticalcoiling axis:N/Achamber arrangement:Planispiralumbilicus:Wide
edge view:Hourglassumbilical or test sutures:Moderately depressedspiral sutures:Moderately depressedshell porosity:
wall texture:Smoothaperture:Equatorialaperture border:Thin lipaccessory apertures:None
periphery:N/Aumb chamber shape:Inflatedsp chbr shape:Inflatedperiph margin shape:Broadly rounded
umb depth:Shallowdiameter mm:max. of holotype 0.40 mmwidth mm:breadth mm:max 0.20 mm
final-whorl chambers:7.0-9.0

References:

Morrow, A.L., (1934). Foraminifera and ostracoda from the Upper Cretaceous of Kansas. Journal of Paleontology, 8: 186-205.


Globigerinelloides bentonensis compiled by the pforams@mikrotax project team viewed: 30-5-2017

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