Sl05

Genus Porodiscus Haeckel, 1881, emend. Kozlova, 1972

"Flustrella Ehrenberg, 1838, p. 122; Porodiscus Haeckel, 1887, p. 491 (part.); Flustrella Campell, 1954, p. 89 (part.); Stylodictya Campbell, 1954, p. 92 (part) Type species Porodiscus concentrica (Ehrenberg) 1838, p. 132. (footnote 1)

"The skeleton is flat or slightly concave in its center, has a rounded outline and is composed of annular equatorial rings (the rest is not developed); first system is of the Archidiscus type (central chamber and one ring), d approx. 30 , very rarely submerged in the skeleton; distance between the annular rings is less than or equal to the diameter of the initial chamber. Main spines are indistinct and as a rule cannot be distinguished from the secondary spines, the number of which in the latter systems exceeds fifty. The rim of the skeleton is either smooth or covered by numerous spines.

Remarks: Rings in Porodiscus sometimes merge into a spiral. Differs from the genus Stylodictya by the absence of cupola-shaped chambers in the first system and by the more or less constant width of the rings. "Early Cretaceous-Recent." (from Petrushevskaya and Kozlova, 1972).

NOTE:

"...Although genus Porodiscus Haeckel, 1887, combining genera Trematodiscus Haeckel, 1862, and Discospira Haeckel, 1862, is a synonym of Ehrenberg's genus Flustrella Ehrenberg, 1838, still, as Haeckel himself wrote (1862), the generic name Flustrella has by mistake come to be used for representatives of the Bryozoa, and this usage has taken such firm root that there is no sense in changing it and re-establishing the name Flustrella for radiolarians, as Campbell and Moore (1954) suggest". (translated from Petrushevskaya, 1967).

Species included:

Porodiscus sp. A

Porodiscus (?) sp. B

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(1) "Porodiscus Haeckel, 1881, p. 459

Frizzell (1951, p. 24) designates Trematodiscus orbiculatus Haeckel in Haeckel, 1862 as the type species of Porodiscus Campbell (1954, p. D89) designates Flustrella concentrica Ehrenberg, 1838. However, these seem inappropriate as neither species was among those first subsequently assigned to Porodiscus. Species first subsequently assigned to Porodiscus are: Porodiscus communis Rust, 1885; P. nuesslinii Rust, 1885; P. simplex Rust, 1885." (from Foreman and Riedel, in press).