Osperleioceras

Osperleioceras is an extinct genus of cephalopod belonging to the family Hildoceratidae.

First species of this genus, Osperleioceras bicarinatum has evolved in what is now France from Harpoceras subplanatum.

[1][2] Genus is similar to Harpoceras, but it is more involute and its whorl section is more triangular.

Suture line is highly incised, ornate and has many auxiliary saddles.

[1] Systematic of this genera is not stable and some different opinions can be found in the literature.

This subgenus is characterized by preserving its ancestral sigmoid ribbing, which is very sparse through at least most of its ontogeny.

[4] To genus Pseudopolyplectus has been also added species P. nadorense, P. subexaratus, P. rivierense and P. reynesi,[3] which can then be considered members of this subgenus.