Gastropoda - Opisthobranchiata
Alternative spelling: Cephalospidea
Parent taxon: Opisthobranchia according to P. J. Wagner 2023
See also Beesley 1998, Beu et al. 1990, Bouchet et al. 2017, Harzhauser 2007, Sepkoski 2002, Sohl 1964, Squires 1984, Squires 1987, Squires 1988, Stilwell et al. 2004, Todd 2001 and Ward and Blackwelder 1987
Sister taxa: Acanthotrophia, Acochlidea, Akeridae, Buscotypus, Canepina, Cephalaspida, Cylindrobullinoidea, Floribella, Gymnosomata, Heteroptygmatis, Heterostrophia, Lutima, Mariottia, Mistostigma, Nicosiaella, Notaspidea, Paronaella, Pseudofusia, Reticulacella, Rhodopemorpha, Scorbinidola, Tectibranchia, Thecosomata, Umbraculomorpha
Subtaxa: Acteonoida Bulloidea Cylichnoidea Cylindrobulloidea Haminoeoidea Notodiaphanidae Philinoidea Ringiculoidea Runcinoidea
Ecology: epifaunal omnivore