CATALOG OF ORIGINAL DESCRIPTIONS: Contusotruncana Korchagin 1982
This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.
Original Description Translation from the Russian. -Test trochospiral. Dorsal side convex, ventral side concave. In the first whorl the chambers are rounded in outline, in later whorls they are flattened, crescentic in outline, with well elevated sutures. Umbilical region broad. Aperture interiomarginal, umbilical. Peripheral margin narrow with two keels.
Family Globotruncanidae. Upper Santonian to Maastrichtian. Extra details from original publication Remarks. - Aside from the above-mentioned features, broad, steep, troughlike depressions which extend from the initial whorl to the peripheral margin are characteristic of the species of this group. In the opinion of a range of investigators (Bolli, 1951, Jour. Pal., vol. 25, no. 2, pp. 187-189; Gandolfi, 1955, op. cit.) there is a close genetic connection between the species of the fornicata and contusa groups. This phylogenetic lineage can be distinctly traced in the upper Senonian, which is one of the prerequisites for combining them in an independent genus. In the course of evolution of Contusotruncana a gradual increase in convexity of the dorsal side is observed - from weakly convex in fornicata to conically convex in late Maastrichtian contusa. In the course of evolution the structure of the umbilical region and apertural apparatus and the crescentic outline of the chambers on the dorsal side remain almost constant in the species making up Contusotruncana. From Globotruncana s. st. it differs by the narrow peripheral margin and closely spaced keels and the crescentic outline of the chambers on the dorsal side.
The following species were included in the genus Contusotruncana by Korchagin (1982):
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