Basic info Taxonomic history Classification Relationships
Morphology Ecology and taphonomy External Literature Search Age range and collections


Radiolaria - Nassellaria - Parvicingulidae


Original description: Test multicyrtid, conical to subconical, with two to six post-abdominal chambers. Cephalis conical to dome shaped without horn. Thorax and subsequent chambers trapezoidal in outline. Earlier chambers covered with layer of microgranular silica, remaining chambers consisting of single layer of regular to subregular pentagonal and hexagonal pore frames. Each post-abdominal chamber with two to three transverse rows of pore frames. Pore frames slightly variable in size, usually with largest pores along partitions. Test with or without poorly developed circumferential ridges. Final post-abdominal chamber closing and with latticed bulbous expansion.

Remarks Pseudoristola, n. gen., differs from Ristola Pessagno and Whalen (1982) by having a test with pore frames more irregular in shape, by lacking well developed circumferential ridges on post abdominal chambers, and by having its final post-abdominal chamber closing with a large latticed bulbous expansion rather than terminating in an open tubular extension.

Etymology: Pseudoristola pseudo(false) Ristola.

Pseudoristola was named by Yeh (1987) [Sepkoski's age data: J Toar-l Sepkoski's reference number: 763].

It was assigned to Parvicingulidae by De Wever et al. (2001); and to Nassellaria by Sepkoski (2002).

Synonymy list
YearName and author
1987Pseudoristola Yeh p. 95
2001Pseudoristola De Wever et al. p. 271
2002Pseudoristola Sepkoski, Jr.

Is something missing? Join the Paleobiology Database and enter the data

phylumRetariaCavalier-Smith 1999
classRadiolariaMüller 1858
superorderPolycystina(Ehrenberg 1867)
orderNassellariaEhrenberg 1875
superfamilyAmphipyndaceaRiedel 1967
familyParvicingulidaePessagno 1977

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

No diagnoses are available