parent_taxon altudoceras
___MASK69___ is one of eleven families of the Neoicocerataceae superfamily . They are an extinct group of ammonoid , which are shelled cephalopods related to squids , belemnites , octopuses , and cuttlefish , and more distantly to the nautiloids . The ___MASK80___ ( from the Latin form of the original Ancient Greek "  ", ' sailor ') is a pelagic marine mollusc of the cephalopod family Nautilidae , the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder , Nautilina . Nautiloids are a large and diverse group of marine cephalopods ( ___MASK55___ ) belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living " ___MASK80___ " and " ___MASK42___ ". Nautiloids flourished during the early Paleozoic era , where they constituted the main predatory animals , and developed an extraordinary diversity of shell shapes and forms . Some 2 , 500 species of fossil nautiloids are known , but only a handful of species survive to the present day . Cuttlebone , also known as cuttlefish bone , is a hard , brittle internal structure ( an internal shell ) found in all members of the family ___MASK57___ , commonly known as cuttlefish , a family within the cephalopods . Cuttlefish are marine animals of the order ___MASK9___ . They belong to the class ___MASK19___ , which also includes squid , octopuses , and nautiluses . Cuttlefish have a unique internal shell , the cuttlebone . Despite their name , cuttlefish are not fish but molluscs . Altudoceras is a genus belonging to the Pseudogastrioceratinae subfamily . They are an extinct group of ammonoid , which are shelled cephalopods related to squids , belemnites , octopuses , and cuttlefish , and more distantly to the nautiloids . The ___MASK29___ ( or ; plural : octopuses , octopodes or octopi ; see below ) is a cephalopod mollusc of the order Octopoda . It has two eyes and four pairs of arms and , like other cephalopods , it is bilaterally symmetric . It has a beak , with its mouth at the center point of the arms . It has no internal or external skeleton ( although some species have a vestigial remnant of a shell inside their mantles ), allowing it to squeeze through tight places . Octopuses are among the most intelligent and behaviorally diverse of all invertebrates . A cephalopod ( pronounced or ) is any member of the molluscan class ___MASK19___ ( Greek plural , " kephalópoda "; " head - feet "). These exclusively marine animals are characterized by bilateral body symmetry , a prominent head , and a set of arms or tentacles ( muscular hydrostats ) modified from the primitive molluscan foot . Fishermen sometimes call them inkfish , referring to their common ability to squirt ink . The study of cephalopods is a branch of malacology known as teuthology . Pseudogastrioceratinae is one of two subfamilies of the ___MASK69___ family . They are an extinct group of ammonoid , which are shelled cephalopods related to squids , belemnites , octopuses , and cuttlefish , and more distantly to the nautiloids .