| Stereoplasmoceratidae Temporal range: Ordovician
| |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | †Orthocerida |
| Genus: | †Stereoplasmoceratidae Kobayashi, 1934 |
Stereoplasmoceratidae is an extinct family of actively mobile aquatic carnivorous cephalopods belonging to the subclass Orthoceratoidea endemic to what would be Asia during the Ordovician living from 490—457.5 mya, existing for approximately 32.5 million years.[1]