pforams@mikrotax - Rugotruncana subcircumnodifer pforams@mikrotax - Rugotruncana subcircumnodifer

Rugotruncana subcircumnodifer

Classification: pf_mesozoic -> Rugoglobigerinidae -> Rugotruncana -> Rugotruncana subcircumnodifer
Sister taxa: R. circumnodifer, R. nothi, R. subcircumnodifer, R. sp.


Citation: Rugotruncana subcircumnodifer (Gandolfi, 1955)
taxonomic rank: Species
Basionym: Globotruncana circumnodifer subcircumnodifer
Synonyms: Globotruncana japonica robusta; Globotruncana japonica

Type images:

Original description: This form is similar to G. fornicata ackermanni, but the Rugoglobigerina habitus is more developed. The test is slightly convex, the chambers are inflated, subangular, with the inflation more pronounced on the umbilical side, so that the faintly beaded double keel (narrow peripheral band) is not exactly in the middle of the chamber, but shifted more toward the dorsal side. The chambers, 4-5 in the last whorl, ar slightly more elongated; the sutures bcome radial in the last chambers; the test is rough, especially in the early stages, and the umbilicus is narrower. The test is dextrally coiled.

Entries in the Catalog of original descriptions: Globotruncana (Rugoglobigerina) circumnodifer subcircumnodifer, Globotruncana japonica robusta, Globotruncana japonica

Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical
sp chamber shape:Petaloidcoiling axis:Lowperiphery:Double keelaperture border:Tegilla
umb chbr shape:Trapezoidalumbilicus:Narrowperiph margin shape:Moderately roundedaccessory apertures:Infralaminal
spiral sutures:Moderately depressedumb depth:Deepwall texture:Finely pustuloseshell porosity:-
umbilical or test sutures:Moderately depressedfinal-whorl chambers:4-5 N.B. These characters are used for advanced search. N/A - not applicable

Geological Range:
Last occurrence (top): within P. hariaensis zone (66.39-67.64Ma, top in Maastrichtian stage). Data source: [copied from Chronos database]
First occurrence (base): within R. calcarata zone (75.06-75.91Ma, base in Campanian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:


Caron, M. (1985). Cretaceous planktic foraminifera. In, Bolli, H. M., Saunders, J. B. & Perch-Nielsen, K. (eds) Plankton Stratigraphy. CUP, Cambridge 17-86. gs

Gandolfi, R. (1955). The genus Globotruncana in northeastern Colombia. Bulletins of American Paleontology. 36: 1-118. gs

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


Rugotruncana subcircumnodifer compiled by the pforams@mikrotax project team viewed: 23-6-2024

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