ammonoid

from WordNet (r) 3.0 (2006)

ammonoid
    n 1: one of the coiled chambered fossil shells of extinct
         mollusks [syn: {ammonite}, {ammonoid}]

from The Collaborative International Dictionary of English v.0.48

ammonoid \ammonoid\ n.
   1. one of the coiled chambered fossil shells of extinct
      mollusks; same as {ammonite}.

   Syn: ammonite
        [WordNet 1.5]