Gastropoda - Opisthobranchiata
Parent taxon: Opisthobranchia according to J. A. Todd 2001
See also Beesley 1998
Sister taxa: Acanthotrophia, Acochlidea, Akeridae, Buscotypus, Canepina, Cephalaspida, Cephalaspidea, Cylindrobullinoidea, Floribella, Gymnosomata, Heteroptygmatis, Heterostrophia, Lutima, Mariottia, Mistostigma, Nicosiaella, Paronaella, Pseudofusia, Reticulacella, Rhodopemorpha, Scorbinidola, Tectibranchia, Thecosomata, Umbraculomorpha
Subtaxa: Tylodinoidea
Ecology: epifaunal
Distribution:
• Miocene of Brazil (1 collection), France (1), Germany (1), Sao Tome and Principe (1)
• Eocene of the United Kingdom (1), United States (24: Alabama, Louisiana, Mississippi, Texas)
• Paleocene of United States (3: Alabama, Maryland, Texas)
Total: 32 collections including 35 occurrences