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Disphaeria petila

Disphaeria petila (Corradini 1973) Yun 1981

NOW Wilsonisphaera. Originally Thalassiphora?, subsequently Disphaeria, thirdly (and now) Wilsonisphaera.
Taxonomic junior synonym: Glaphyrosphaera glabra, according to Schiøler and Wilson (1995, p.511).

Holotype: Corradini, 1973, pl.31, fig.2
Paratype: Corradini, 1973
Locus typicus: Viano, Reggio Emilia, Italy
Stratum typicum: Senonian

Original diagnosis: Corradini, 1973, p. 186: Thalassiphora petila
Test with spherical to ellipsoidal central body possessing a thin, smooth wall. Periphragm in form of a very thin membrane, spherical to subpolygonal in outline, typically with a convex triangular opening. Endophragm wrinkled and periphragm irregularly folded.
Dimensions: Ho]otype: diameter of the central body 40x50 Ám, overall diameter 85x103 Ám, dimensions of the outer "archeopyle" 20x50 Ám. Range diameter of the central body 40-(43)-48x45-(50)-55 Ám, overall diameter 80-(90)-100x90-(100)-108 Ám, dimensions of the outer "archeopyle" 15-(25)-30x50-(60)-651 Ám.

Original description: Corradini, 1973, p. 186: Thalassiphora petila
The outer wide wing lamella is probably supported bv refoldings of the membrane itself on the dorsal surface of the central body. The folded or wrinkled thin walls make uncertain the identification of an archcopyle on the central body.
An opening, convex-triangular in shape, is normally present on the outer wall, suggesting a precingular archeopyle. Rarely, the periphragm presents short spines or small sticks. Often the outline of the external membrane is expressed by angular margins formed by the junction of two or more linear folds.

Affinities:
Corradini, 1973, p. 186: Thalassiphora petila
This new form resembles, in general outline, members of the genus Thalassiphora, especially the species T. delicata Williams & Downie 1966, (Eocene of England and Oligocene of Rumania - Baltes 1967) from which it differs in the corner-edged outline, in the presence of spines and of a convex triangular opening on the periphragm and in the lack of perforations.
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