Specimens which cannot be assigned to established species
| Daughter taxa (time control age-window is: 0-800Ma) | ||||
| | | Rectoguembelina cretacea | |
| Rectoguembelina sp. Specimens which cannot be assigned to established species | ||||
Taxonomy
Original description: Test with the early chambers arranged in a biserial manner similar to Guembelina, later chambers uniserial and rounded in transverse section; chambers all inflated, distinct; sutures distinct, depressed; wall calcareous, thin, very finely perforate; aperture in the early stages similar to Guembelina, in the adult terminal, rounded, with a distinct neck.
Entries in the Catalog of original descriptions: Rectoguembelina
Distinguishing features:
Parent taxon (Heterohelicidae): Aperture symmetrical, ranging from a low slit to a high arch at the base of the final chamber, becoming terminal in uniserial taxa.
This taxon: Initially biserial, later part of test uniserial, globular chambers throughout.
Geological Range:
Last occurrence (top): near top of Danian Stage (85% up, 62.3Ma, in Danian stage). Data source: Total of range of species in this database
First occurrence (base): in mid part of Maastrichtian Stage (48% up, 69.2Ma, in Maastrichtian stage). Data source: Total of range of species in this database
Plot of range and occurrence data:
References:
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Rectoguembelina compiled by the pforams@mikrotax project team viewed: 20-3-2023
Short stable page link: https://mikrotax.org/pforams/index.php?id=110489 Go to Archive.is to create a permanent copy of this page - citation notes |
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