Ophiocistioidea
| Ophiocistioidea Temporal range:  | |
|---|---|
| Restoration of Eucladia woodwardi dorsal (top) and ventral (botoom) views | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Echinodermata | 
| Subphylum: | Echinozoa | 
| Class: | Ophiocistioidea | 
Ophiocistioidea is a class of extinct echinoderms from the Palaeozoic and early Mesozoic. They most likely form a paraphyletic grade along sea cucumber stem lineage, although some sources still consider the question of ophiocistioid monophyly unresolved.