Revised description:Stylosphaerida with one single lattice-sphere and two equal opposite spines, connected at the distal end by a circular or elliptical ring.
Remarks:The genus Saturnalis (with simple lattice-sphere) and the two similar genera Saturnulus (with two concentric spheres) and Saturninus (with three spheres) form together the small peculiar group of Saturnalida, distinguished by a remarkable circular or elliptical ring, connecting the distal ends of the two equal opposite polar spines. This ring indicates a certain equatorial plane, and therefore brings these Sphaeroidea into relation with the Discoidea.
Stratigraphic range:[No information given]
Etymology:From the Greek saturnalis = similar to Saturnus.
Subsequent descriptions:YES

- SaturnalisHaeckel, 1881a, p.450; 1887a, p.131 - SaturnulusHaeckel, 1881a, p.451; 1887a, p.141

Emended description:Stylosphaeridae with two concentric lattice spheres and two equal opposite spines, connected at the distal end by a circular or elliptical ring.
Remarks:According to Haeckel (1887a), Saturnalis has a single lattice shell and Saturnulus a double one. In all other respects the genera are apparently identical. This distinction does not seem well founded, because the medullary shell is very delicate and so may easily be destroyed or not originally developed. Generally, small portions of the two radial beams can be seen even if the medullary shell is absent. Thus, it would appear that two lattice spheres are normally present in completely developed individuals. Since Saturnalis is the type genus of the subfamily Saturnalinae, erected by Deflandre (1953), and since it has been used in forming the names of other genera (e.g., Spongosaturnalis Campbell and Clark, 1944b), Saturnalis has been chosen as the name for the revised genus, with Saturnalis circularis as the type species.
Stratigraphic range:[No information given]
Subsequent descriptions:YES

Emended description:Saturnalinae dépourvu de rayons auxiliaires ou subsidiaires, à anneau simple, plat ou rond, à carène ou non. Les épines sont souvent absentes.
[Saturnalinae without auxiliary or subsidiary rays, and with a simple ring, flat or circular in cross section, keel being present, or not. Often no spines.]
Remarks:Ce genre diffère des autres Saturnalinae par son anneau simple dépourvu d'épines et circulaire en section le plus souvent. La coque centrale sphérique comporte généralement un ou deux réseaux treillissés bien distincts. Au Paléocène-Eocène quelques formes portent une ou plusieurs épines, mais la plupart des spécimens cénozoiques sont dépourvus de toute épine sur l'anneau. Il est également à noter qu'il a été rencontré deux spécimens cénozoiques (et seulement deux) présentant des épines polaires (communication personnelle de W.R. Riedel et A. Sanfilippo, 1983). La rareté de ce type de forme ne permet aucune conclusion solide (existence de formes cénozoiques à épines polaires ?, forme biologiquement monstrueuse ?, forme récurrente d'un ancêtre phylogénique ?). Le genre Saturnalis semble évoluer à partir d'Acanthocircus, ou éventuellement de Mesosaturnalis, par diminution puis perte des épines. La forme circulaire en section de l'anneau correspondrait à un stade ultime du développement d'une large carène sur l'anneau (par intégration de la carène sur l'anneau plat).
[This genus differs from the other Saturnalinae by a simple ring without spines and with a mostly circular cross section. The central spherical shell generally includes one or two latticed meshworks. Paleocene to Eocene forms with one or more spines, but for the most part Cenozoic representatives are without spines on the ring. Two Cenozoic specimens with polar spines were, however, observed (pers. com. W. R. Riedel and A. Sanfilippo). These forms are so rare that it is difficult to suggest that: (1) Cenozoic forms can have polar spines ?, (2) these specimens are biological monsters ?, (3) or there is some recurrent appearance of ancestral representatives ?. The genus Saturnalis seems to evolve from Acanthocircus or possibly from Mesosaturnalis by reduction and disappearance of the spines. The circular cross section of the ring could be related to the late evolutionary step of a wide ring keel merging with the ring itself.]
Stratigraphic range: Paleocene - Recent. Cenozoic.
Subsequent descriptions:YES

Emended description: Saturnalis Haeckel comprises species with medullary shell and a microsphere bearing an axial apical ray.
Description of Family Saturnalidae Deflandre, emend. Dumitrica, 1985, p. 190:Forms with spheric or subspheric, spongy or lattice shell and two polar rays in most cases united distally through a single or multiple equatorial ring. Microsphere heteropolar, with a characteristic primary skeleton consisting of a median bar, four basal rays and a primary ring.
Remarks:Saturnalis was originally defined as having no medullary shell. In agreement with Nigrini (1967) who first revised it, it includes also Saturnulus Haeckel with a single medullary shell. Saturninus Haeckel is herein also regarded as a synonym of Saturnalis, its very delicate, cobweb shaped mesh-work connecting the microsphere with the cortical shell reminding the very delicate spongy meshwork around the microsphere of Saturnalis circularis.
Stratigraphic range:[No information given]
Subsequent descriptions:?

Literature cited:- Campbell, A. S. and B. L. Clark (1944b). Radiolaria from Upper Cretaceous of Middle California. Geological Society of America Special Paper 57: 1-61.
- Deflandre, G. (1953). Radiolaires fossiles. Traité de Zoologie. P. P. Grassé. Paris, France, Masson. vol. 1: 389-436.
- De Wever, P. (1984a). Révision des radiolaires mésozoiques de type Saturnalidae, proposition d'une nouvelle classification (Revision of Mesozoic saturnalid-type radiolarians. Proposition of a new classification). Revue de Micropaléontologie 27(1): 10-19.
- Haeckel, E. (1881a). Entwurf eines Radiolarien-Systems auf Grund von Studien der Challenger-Radiolarien (Basis for a radiolarian classification from the study of Radiolaria of the Challenger collection). Jenaische Zeitschrift für Naturwissenschaft, 15:418-472.
- Haeckel, E. (1887a). Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876. Report on the Scientific Results of the Voyage of the H.M.S. Challenger, Zoology, 18, clxxxviii + 1803.
- Nigrini, C. (1967). Radiolaria in pelagic sediments from the Indian and Atlantic Oceans. Bulletin of the Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 11: 1-125.