Cephalaspidea

order of gastropods Cephalaspidea (Cephalaspidea) is an order comprising closely related families of organisms. It contains 8 families with 13 known species. Key family groups include Acteonidae, Bullidae, Cylichnidae, Diaphanidae, Haminoeidae, and Philinidae. Among its members, 2 species are currently classified as threatened (Critically Endangered, Endangered, or Vulnerable). It belongs to Gastropoda (Gastropoda).