pforams@mikrotax - Pseudoguembelina praehariaensis pforams@mikrotax - Pseudoguembelina praehariaensis

Pseudoguembelina praehariaensis

Classification: pf_mesozoic -> Heterohelicidae -> Pseudoguembelina -> Pseudoguembelina praehariaensis
Sister taxa: P. costellifera, P. costulata, P. excolata, P. hariaensis, P. kempensis, P. palpebra, P. praehariaensis, P. semicostata, P. sp.


Citation: Pseudoguembelina praehariaensis Tur&Huber in Huber et al. 2022
taxonomic rank: species
Basionym: Pseudoguembelina praehariaensis

Type images:

Original description: Diagnosis: Pseudoguembelina praehariaensis n. sp. is characterized by its long and narrow
biserial test with subparallel sides in the adult portion; final chamber vertically stretched and
peripherally flattened; small accessory apertures visible long the median suture.

Description: Test is biserial throughout, long and narrow, rapidly flaring in the short juvenile
portion with subparallel sides in the adult portion. The adult portion consists of 3-4 pairs of
subquadrate chambers that increase very slowly or show no increase in size. Final chamber is
always stretched in the growth direction and is peripherally flattened. Surface is covered by very
thin discontinuous costae. Aperture is a wide, low arch, bordered by a narrow rim. Small
accessory apertures occur on adult chambers along the median suture.

Entries in the Catalog of original descriptions: Pseudoguembelina praehariaensis

Distinguishing features:
Parent taxon (Pseudoguembelina): Biserial throughout, secondary sutural apertures along the median suture, partially covered by flaplike projections. Test usuually costate.
This taxon: Long and narrow test with subparallel sides in the adult portion; final chamber vertically stretched and peripherally flattened.

Holotype USNM 527800 length 358 µm, width 196 µm, and maximum breadth 112 µm; paratype USNM 527801 length 310 µm, width 164 µm, and maximum breadth 107 µm; paratype USNM 527802 length 405 µm, width 195 µm, and maximum breadth 119 µm.

Character matrix
test outline:Elongatechamber arrangement:Biserialedge view:Compressedaperture:Interiomarginal
sp chamber shape:Inflatedcoiling axis:N/Aperiphery:N/Aaperture border:Thin lip
umb chbr shape:Inflatedumbilicus:N/Aperiph margin shape:Moderately roundedaccessory apertures:Sutural
spiral sutures:Moderately depressedumb depth:N/Awall texture:Finely costateshell porosity:Finely Perforate: 1-2.5µm
umbilical or test sutures:Moderately depressedfinal-whorl chambers:2-2 N.B. These characters are used for advanced search. N/A - not applicable

Most likely ancestor: Pseudoguembelina palpebra - at confidence level 1 (out of 5). Data source: Huber et al. 2022, p. 33.

Geological Range:
Last occurrence (top): at top of P. hariaensis zone (100% up, 66.4Ma, in Maastrichtian stage). Data source: [Huber et al. 2022, Fig. 5]
First occurrence (base): in lower part of A. mayaroensis zone (25% up, 68.9Ma, in Maastrichtian stage). Data source: [Huber et al. 2022, Fig. 5]

Plot of range and occurrence data:


Huber, B. T., Tur, N., Self-Trail, J. & MacLeod, K. G. (2022a). Calcareous plankton biostratigraphic fidelity and species richness during the last 10 m.y. of the Cretaceous at Blake Plateau, subtropical North Atlantic. Cretaceous Research. 131: 1-42. gs


Pseudoguembelina praehariaensis compiled by the pforams@mikrotax project team viewed: 16-6-2024

Taxon Search:
Advanced Search

Short stable page link: Go to to create a permanent copy of this page - citation notes

Add Comment

* Required information
Captcha Image
Powered by Commentics


No comments yet. Be the first!