In order to complete the study of the very rich early Tithonian
(Hybonoticeras hybonotum Zone) radiolarian fauna from the Muhlheim
Member of the Mornsheim Formation outcropping in the Solnhofen area, the
taxa of the family Saturnalidae are described. Although rather rare, the
Saturnalidae of this member contain 14 species, ten of which are new.
These species belong to four genera, one of which is new (Moebicircus n.
gen.), and two subfamilies (Hexasaturnalinae and Saturnalinae). The
taxonomy at generic level of these late Jurassic radiolarians is founded
on the basis of the position of the blades along the ring and number and
morphology of the spines. Type of spines (simple or forked) has either
species level value or none, depending on species. Special attention was
given to anomalies, which sometimes are rather frequent, since they can
give information of paleobiological and paleoecological orders. Among
them frequent cases of open ring and additional spines with
Dicerosaturnalis and Siamese twins skeletons with Spongosaturninus and
Dicerosaturnalis are to be noted. The authors hope that this new
taxonomy will give a better image of the evolution and radiation of the
Saturnalidae during the Tithonian.