Specimens which cannot be assigned to established species
| Daughter taxa (time control age-window is: 0-800Ma) | ||||
| | Falsotruncana douglasi | ||
| | | Falsotruncana loeblichae | |
| | | Falsotruncana maslakovae | |
| Falsotruncana sp. Specimens which cannot be assigned to established species | ||||
Taxonomy
Original description: Test à trochospire basse, enroulement toujo urs senestre. Contour lobe. profil tronque par un bandeau peripherique imperfore marque parfois jusque sur les dernieres loges. borde par deux carenes pustu- leuses visibles au mains sur les trois permieres loges du dernier tour. Dans cer- tains cas, bandeau peripherique et carene pustuleuse sont nettement perfores. Ouverture principale ombilicale-extraombilicale presque peripherique, ourlee d'une levre etroite. Ombilic peu profond, evase, sans portici ni tegilla. Sutures ombilicales radiates et deprimees. Sutures spirales, radiates apeu arquees, deprimees. Chez certaines formes primitives, la surface des premieres loges (face spirale) est tres pustuleuse.
Entries in the Catalog of original descriptions: Falsotruncana
Distinguishing features:
Parent taxon (Hedbergellidae): Test trochospirally coiled, primary aperture interiomarginal, extraumbilical-umbilical, with prominent apertural lip, apertures of earlier chambers remain visible around the umbilical region; no sutural secondary apertures.
This taxon: Test in low trochospiral coil, compressed, chambers petaloid, sutures radial, slightly curved, depressed on the spiral side, radial and depressed around the shallow umbilicus on the umbilical side, peripheral margin truncate to narrowly rounded, with imperforate carinal band bordered in the earlier chambers of the final whorl by two low pustulose keels, peripheral outline lobulate; wall calcareous, perforate, rare perforations may occur in the generally imperforate carinal band, surface of earlier chambers pustulose, especially on the spiral side; primary aperture interiomarginal, umbilical-extraumbilical, nearly equatorial, bordered with a thin lip but lacking portici or umbilical extensions.
Geological Range:
Last occurrence (top): at top of Turonian Stage (97% up, 89.9Ma, in Turonian stage). Data source: Total of range of species in this database
First occurrence (base): near base of Turonian Stage (9% up, 93.5Ma, in Turonian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
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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Falsotruncana compiled by the pforams@mikrotax project team viewed: 20-3-2023
Short stable page link: https://mikrotax.org/pforams/index.php?id=110101 Go to Archive.is to create a permanent copy of this page - citation notes |
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