Taxonomy
Original description: Test tiny, biserial, tapering gradually; chambers globular, closely appressed; sutures distinct, depressed, more angular toward the base, nearly straight among the later chambers; wall calcareous, finely perforate, surface smooth; aperture low, semilunate, at the base of the last formed chamber.
Entries in the Catalog of original descriptions: Guembelina washitensis
Emended description:
Character matrix
| test outline: | Elongate | chamber arrangement: | Biserial | edge view: | Compressed | aperture: | Equatorial |
| sp chamber shape: | Globular | coiling axis: | N/A | periphery: | N/A | aperture border: | Thin porticus |
| umb chbr shape: | Globular | umbilicus: | Wide | periph margin shape: | N/A | accessory apertures: | None |
| spiral sutures: | Moderately depressed | umb depth: | N/A | wall texture: | Smooth | shell porosity: | Microperforate: <1µm |
| umbilical or test sutures: | Moderately depressed | final-whorl chambers: | 2-2 | N.B. These characters are used for advanced search. N/A - not applicable | |||
Geological Range:
Last occurrence (top): within H. helvetica zone (92.51-93.52Ma, top in Turonian stage). Data source: [copied from Chronos database]
First occurrence (base): within P. ticinensis zone (101.92-103.94Ma, base in Albian stage). Data source: [copied from Chronos database]
Plot of range and occurrence data:
Tappan, H. (1940). Foraminifera from the Grayson formation of Northern Texas. Journal of Paleontology. 14(2): 93-126. gsReferences:

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Protoheterohelix washitensis compiled by the pforams@mikrotax project team viewed: 9-10-2026
Short stable page link: https://mikrotax.org/pforams/index.php?id=110448 Go to Archive.is to create a permanent copy of this page - citation notes |
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