Order Nudibranchia Blainville 1814 (sea slug)
Parent taxon: Nudipleura according to P. Bouchet et al. 2017
See also Beesley 1998
Sister taxon: Pleurobranchida
Subtaxa: Aeolidina Arminina Cladobranchia Dendronotina Doridina
Ecology: epifaunal