anaptychus

1 definition found

anaptychus - Collaborative International Dictionary of English v.0.48 :

  Anaptychus \An*ap"ty*chus\, n.; pl. Anaptichi. [NL., fr. Gr. ?
     unfolding; 'ana` back + ? to fold.] (Paleon.)
     One of a pair of shelly plates found in some cephalopods, as
     the ammonites.
     [1913 Webster]