Main Entry:

am·mo·nite

Pronunciation:

\ˈa-mə-ˌnīt\

Function:

noun

Etymology:

New Latin ammonites, from Latin cornu Ammonis, literally, horn of Ammon

Date:

1758

: any of a subclass (Ammonoidea) of extinct cephalopods especially abundant in the Mesozoic age that had flat spiral shells with the interior divided by septa into chambers

— am·mo·nit·ic \ˌa-mə-ˈni-tik\ adjective

[ammonite illustration]