Gastropoda - Epitonioidea - Epitoniidae
Alternative spelling: Crassiscala
Parent taxon: Opalia according to J.-M. Pacaud and J. Le Renard 1995
See also Allison 1955 and Sepkoski 2002
Sister taxa: Opalia (Contemniscala), Opalia (Dentiscala), Opalia (Granuliscala), Opalia (Nodiscala), Opalia (Opalia), Opalia (Pliciscala), Opalia (Rugatiscala), Opalia atra, Opalia borealis, Opalia cavea, Opalia crenatoides, Opalia infrequens, Opalia mathewsonii, Opalia montereyensis, Opalia spongiosa, Opalia varicostata, Scala (Opalia) calvertensis, Scala (Opalia) cyclostoma, Scala (Opalia) prunicola, Scala (Opalia) reticulata, Scala (Opalia) thomasi, Scalaria (Opalia) annulata
Subtaxa: Crassiscala subterranea Opalia (Crassiscala) riachuelanum
Ecology: slow-moving low-level epifaunal carnivore
Distribution:
• Eocene of the United Kingdom (2 collections)
• Cretaceous of Mexico (1)
Total: 3 collections each including a single occurrence