Original Description Test trochoidal, elongate in direction of end chamber. Chambers truncate at apertural side, increasing in size as added (end chamber about twice the size of the penultimate one), subglobular in major portion of adult whorl, flattened at the spiral side and peripherally keeled in the end stage. Chambers arranged in about 2 whorls, those of the last volution overlapped by the preceding ones. Sutures on the spiral side curved in direction of coiling, those on the umbilical side more or less straight to slightly curved backward. Umbilicus large, subcircular, with fragments of covering plate along truncate edges of chambers. Aperture large, elongate-arcuate, with minute liplike projection leading into the umbilicus. Wall apparently thick, surface coarsely rugose, especially in earlier chambers. Ornamentation suggesting a variant of the meridional pattern of Rugoglobigerina. Size: Etymology: Extra details from original publication Remarks.—The new genus Trinitella is monotypic and named after Trinidad, B. W. I. It shows affinities to Rugoglobigerina through the early Globigerina-like portion of the test and to Globotruncana through the keeled end chamber, flattened at the spiral side. Trinitella, however, does not appear to be directly connected with the highly evolved Globotruncanas of the Globotruncana mayaroensis zone (Bolli, 1951) and thus is tentatively regarded to represent an offshoot from Rugoglobigerina. The flattened and keeled end stage and the overlapping chambers of the last volution easily dis-tinguish Trinitella from Rugoglobigerina.
Occurrence.—Globotruncana mayaroensis zone. Common. Possibly also Globotruncana gansseri zone. Guayaguayare beds, Maestrichtian, Upper Cretaceous, Trinidad, B. W. I. Editors' Notes
Brönnimann, P. (1952c). Globigerinidae from the Upper Cretaceous (Cenomanian-Maestrichtian) of Trinidad, B. W. I. Bulletins of American Paleontology. 34(140): 1-70. gs
Trinitella compiled by the pforams@mikrotax project teamviewed: 31-1-2023