Specimens which cannot be assigned to established species
Taxonomy
Original description: Globotruncaninae, welche vom Anfang an das Protoforamen verloren haben oder nie ausbildeten Auch ist nicht unmoglich, dass das Protoforamen mit dem Deuteroforamen verschmolzen ist. Daher ist die ventrale Kammerwand nicht schief ausgebildet, sondern stutzt sich gegen den Nabel mitder Umbilicallipe (Tenon) ab; die Grenze des perforierten Wandteiles mit der porenlosed Lippe ist parallel zum Nabel. Die Suturen der Kammern sind radial auf der Ventralseite.Familie Marginolamelidae. Unter familie Globotruncaninae. Cenoman-Maastricht:
Entries in the Catalog of original descriptions: Marginotruncana, Sigalitruncana
Distinguishing features:
Parent taxon (Globotruncanidae): Test trochospiral, chambers angular, periphery truncate or carinate; primary aperture umbilical, covered by a spiral system of tegilla that is provided with accessory intralaminal and infralaminal apertures.
This taxon: Test trochospiral, biconvex to planoconvex, sutures sigmoidal, especially on the umbilical side, curved, elevated and may be beaded on the spiral side, imperforate carinal band between the two peripheral keels, peripheral outline entire to lobulate; wall calcareous, perforate, surface smooth to pustulose; primary aperture interiomarginal and extraumbilical-umbilical, bordered by a triangular porticus, those of successive apertures fusing and may even form true tegilla, infralaminal and occasionally intralaminal accessory apertures present.
Emended description:
Morphology:
Wall type:
Size:
Geological Range:
Last occurrence (top): in lower part of Campanian Stage (38% up, 79.2Ma, in Campanian stage). Data source: Total of range of species in this database
First occurrence (base): at base of Turonian Stage (0% up, 93.9Ma, in Cenomanian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
Hofker, J. (1956a). Die Globotruncanen von Nordwest-Deutshland und Holland. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen. 103: 312-340. gs Korchagin, V. I. (1982). Систематика глоботрунканин - Systematics of the Globotruncanids. Byulleten Moskovskogo Obshchestva Ispytateley Prirody Otdel Geologicheskiy. 57(5): 114-121. gs Loeblich, A. R. & Tappan, H. (1988). Foraminiferal Genera and Their Classification (Volume I-II). Van Nostrand Reinhold Co., New York. 1-1059. gsReferences:
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Marginotruncana compiled by the pforams@mikrotax project team viewed: 8-2-2023
Short stable page link: https://mikrotax.org/pforams/index.php?id=110328 Go to Archive.is to create a permanent copy of this page - citation notes |
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