pforams@mikrotax - Trinitella scotti pforams@mikrotax - Trinitella scotti

Trinitella scotti

Classification: pf_mesozoic -> Rugoglobigerinidae -> Trinitella -> Trinitella scotti
Sister taxa: T. scotti, T. suturis, T. sp.


Citation: Trinitella scotti Bronnimann 1952
taxonomic rank: Species
Basionym: Trinitella scotti
Taxonomic discussion: The initial portion of this form seems to be identical with that of typical representatives of Rugoglobigerina (Rugoglobigerina) rugosa (Plummer) [Globigerina rugosa, 1927] and Rugoglobigerina (Rugoglobigerina reicheli Bronnimann." [copied from Chronos database]

Type images:

Original description: The trochoidal test is small to medium-sized and elongate in direction of the end chamber. The five to six chambers of the adult volution are subglobular at first. They then become flattened at the spiral side, forming a keel. These new features pertain to the end chamber, occasionally also to the two last ones. The end chamber is about twice as large as the penultimate one and elongate in radial direction. About two whorls can be recognized on the spiral side. The slightly depressed initial portion is not clearly exposed, and no information regarding the arrangement of the early chambers can be obtained due to the coarse rugosities or adhering matrix.
The umbilicus is large, deep, subcircular and probably provided with a delicate covering plate. Only fragments of this plate are preserved along the border of the umbilicus. The chambers are truncate toward the apertural side and increase in size as added. Seen from the spiral side, each adult chamber overlaps the next one. The sutures on the spiral side, therefore, are strongly curved in the direction of coiling. Those on the umbilical side are deep and relatively straight to slightly curved backward.
The arcuate apertures open into the umbilicus. The walls seem to be thick, and the surface, especially of the inner chambers, is strongly rugose. The ornamentation appears to be of the meridional pattern, although no central point was noted on the surface of the end chamber.
The counted individuals are invariably dextrally coiling.

Entries in the Catalog of original descriptions: Trinitella scotti, Rugoglobigerina (Rugoglobigerina) bronnimanni

Character matrix
test outline:Lobatechamber arrangement:Trochospiraledge view:Planoconvexaperture:Umbilical
sp chamber shape:Petaloidcoiling axis:Very lowperiphery:Single keelaperture border:Tegilla
umb chbr shape:Trapezoidalumbilicus:Wideperiph margin shape:Subangularaccessory apertures:Infralaminal
spiral sutures:Moderately depressedumb depth:Deepwall texture:Meridional costellaeshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:5-5.5 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 G. gansseri zone (71.73-73.80Ma, base in Campanian stage). Data source: [copied from Chronos database]

Plot of range and occurrence data:


Brönnimann, P. (1952c). Globigerinidae from the Upper Cretaceous (Cenomanian-Maestrichtian) of Trinidad, B. W. I. Bulletins of American Paleontology. 34(140): 1-70. gs

Huber, B. T., Tur, N., Self-Trail, J. & MacLeod, K. G. (2022a). Calcareous plankton biostratigraphic fidelity and species richness during the last 10 m.y. of the Cretaceous at Blake Plateau, subtropical North Atlantic. Cretaceous Research. 131: 1-42. gs

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

Postuma, J. A. (1971). Manual of planktonic foraminifera. Elsevier for Shell Group, The Hague. 1-406. gs

Smith, C. C. & Pessagno, E. A. (1973). Planktonic foraminifera and stratigraphy of the Corsicana formation (Maestrichtian) North-central Texas. Cushman Foundation for Foraminiferal Research, Special Publication. 12: 1-67. gs O


Trinitella scotti compiled by the pforams@mikrotax project team viewed: 1-3-2024

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