ammonoid

am·mo·noid

A0259300 (ăm′ə-noid′)n. An extinct cephalopod mollusk of the subclass Ammonoidea of the Devonian to Cretaceous Periods, having a straight or coiled chambered shell characterized by more or less intricate suture patterns where the septa between individual chambers join the outer shell wall.

ammonoid

(ˈæməˌnɔɪd) nany of the extinct group of sea-dwelling cephalopod molluscs with coiled and chambered shells

am•mo•noid

(ˈæm əˌnɔɪd)

n. ammonite.

Thesaurus

Noun

1.

ammonoid - one of the coiled chambered fossil shells of extinct mollusksammonitefossil - the remains (or an impression) of a plant or animal that existed in a past geological age and that has been excavated from the soil