the world > animals > invertebrates > subkingdom Metazoa > grade Triploblastica or Coelomata > class Cephalopoda > [noun] > order Tetrabranchiata > family Ammonitidae > member of (5)
A fossil cephalopod having a shell of a hooked shape.
A fossil Cephalopod, with a discoidal shell having lobed sutures, with the lobes oviculated.
A fossil cephalopod of the order Ammonoidea, comprising the ammonites and related genera.