Olcostephanidae
Olcostephanidae is an extinct ammonoid cephalopod family belonging to the superfamily Perisphinctoidea. These fast-moving nektonic carnivores lived from the Jurassic to the Cretaceous period.
Genera
Source:- Bihenduloceras
- Olcostephanus Neumayr, 1875
- Saynoceras
- Subastieria Spath, 1923
- Taraisites Cantú-Chapa, 1966
- Valanginites Sayn, 1910