Sosioceras

Sosioceras is an Upper Permian shouchangoceratin pseudohaloritid characterized by a subdiscoidal shell, about 2 cm in diameter, marked by growth lines, as with Neoaganides, and having a mature peristome with a double constriction near the periphery. The suture also closely resembles that of Neoaganides.

Sosioceras Temporal range: Late Permian PreꞒ Ꞓ O S D C P T J K Pg N
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Order:	Goniatitida
Family:	Pseudohaloritidae
Genus:	Sosioceras Frest et al., 1981

Sosioceras is found in the Upper Permian Sosio limestone of Sosio valley, in Sicily, first described by Gemmellaro, 1880, as Brancoceras pygmaeum, thought be a rare element of the Sosio fauna. Miller and Furnish, 1957, redefined it as Neoaganides pygmaeum (Gemmellero) on the basis of close similarity of size, form, and suture to Neoaganides grahamensis. Based on features of the peristome and recognition of a wrinkle layer, unique in this family, Frest et al., 1981, renamed the genus Sosioceras, in reference to its location, arguing for its separation. The type and only species is Sosioceras pygmaeum (Gemmellero, 1880).

References

• Frest, T.J, B.F Glenister and W.M Furnish; 1981. Pennsylvanian-Permian Cheiloceratacean Ammonoid Families Maximitidae and Pseudohaloritidae. Memoir 11, the Paleontological Society; Jour Paleo V 55, May 1981, supplement.
• Miller, A.K. and W.M Furnish, 1957. Permian Ammonoids from Southern Arabia. Journal of Paleontology V.31, no. 6, p 1043 _, Nov 1957.