CATALOG OF ORIGINAL DESCRIPTIONS: Prosphaeroidinella valleriae Brönnimann, Whittaker & Parisi 1988

This page provides data from the catalog of type descriptions. The catalog is sorted alphabetically. Use the current identification link to go back to the main database.


Higher levels: pf_cat -> P -> Prosphaeroidinella -> Prosphaeroidinella valleriae
Other pages this level: P. parkerae, P. valleriae,

Prosphaeroidinella valleriae

Citation: Prosphaeroidinella valleriae Brönnimann, Whittaker & Parisi 1988
Rank: Species
Type locality: Shales in the Radicofani Basin, southern Tuscany, Italy.
Type age: Lower Pliocene, Zone MPI3
Holotype Repository: London, UK; NHM

Current identification/main database link:


Original Description
Prosphaeroidinella valleriae occurs in many samples of the examined portion of the MPI 3 interval, usually associated with P. disjuncta (Finlay) and apparently interconnected with this species by transitional morphologies (see pl. I, fig. 5). No specimens have been broken up hence no comments can be made on the wall structure.
Surface structure: The surface structure is as in P. disjuncta with thickening around the slot like apertures. It is characterized by a smoothing out of the polygonal pattern but in no case a glossy and smooth surface is developed as in Sphaeroidinellopsis and Sphaeroidinella hence no hyalinarium is developed (figs. 1, 2).
Wall structure: The wall structure is probably as in P. parkerae Ujiie, 1976. There is no hyalinarium developed.
Apertural features: The 2 illustrated specimens of P. valleriae (figs. 1, 2) show a single interiomarginal slit, virtually horizontal, with a distinct rim on the upper side. This aperture is quite similar to that of P. disjuncta and P. parkerae.
Overall shape of the test: The test is a low trochospire with 4 chambers in the final whorl. The first chamber of the final whorl is usually very small and tends to become suppressed. The final chamber is typically spatuliform in outline.

Morphological description. Holotype: A free, tightly enrolled low trochospiral specimen with 4 subglobular chambers in final whorl. First chamber of final whorl small in relation to 3 later chambers. Final chamber tends to become radially elongate. Equatorial outline of test almost oval. Sutures distinct. Single interiomarginal umbilical aperture elongate slit of letterbox type. Upper border of aperture with thick rim. Surface polygonal with secondary thickening around aperture.

Size: Holotype: Maximum diameter of test about 240 µm, minimum diameter 145 µm. • Apertural slit 16 µm high, 30 to 40 µm long. Paratype: Maximum diameter of test 220 µm, minimum diameter 130 µm.

Extra details from original publication
Paratype. The paratype (fig. 2), shows the same surface and apertural features as the holotype. Apertural rim in this specimen stronger than in holotype. Secondary thickening around aperture well developed.

Other specimens.- Five individuals from sample RPI 49 have been illustrated by figs. 3, 4, 6-8. They correspond in surface and apertural features well with the holotype of  Prosphaeroidinella valleriae. Their maximum dimensions range from 150 to 200 µm.

Remarks. - P. valleriae differs by the oval outline of the test, the less individualized chambers, the relatively small chamber ofthe final whorl, and by the tendency to develop a spatuliform final chamber from P. disjuncta. From P. parkerae it differs by the less coarse polygonal surface, and by secondary thickening of the wall. It is generally represented by relatively small specimens of not more than 4 chambers in the final whorl. Transitional forms occur between P. disjuncta and P. valleriae which is possibly the ancestor of Sphaeroidinellopsis seminulina (Schwager)."

References:

Bronnimann, P., Whittaker, J. E. & Parisi, G. (1988). Prosphaeroidinella Ujiie in the Lower Pliocene of southern Tuscany, central Italy, with remarks on the wall struture and taxonomy of the Sphaeroidinellidae. Bollettino della Societa Paleontologica Italiana. 27(3): +344-347+. gs :: ::


logo

Prosphaeroidinella valleriae compiled by the pforams@mikrotax project team viewed: 7-7-2020

Taxon Search:
Advanced Search

Short stable page link: http://mikrotax.org/pforams/index.php?id=132528 Go to Archive.is to create a permanent copy of this page - citation notes



Comments (0)

No comments yet on this page. Please do add comments if you spot any problems, or have information to share

Add Comment

* Required information
1000
Captcha Image
Powered by Commentics