cephalopod

A cephalopod is any member of the molluscan class Cephalopoda. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot.

Extant organisms

• cuttlefish
• octopus
• umbrella octopus
• nautilus
• squid
• giant squid
• vampire squid

Extinct organisms

• ammonite