'Ammonite' originates from Latin, specifically the word 'ammonites', which referred to the fossil shells resembling the horns of the Egyptian god Ammon.

'Ammonite' changed from the Latin word 'ammonites', which was adopted into English in the 18th century to describe these fossilized creatures.

Initially, it meant 'fossil shells resembling ram's horns', but over time it evolved into its current meaning of 'an extinct group of marine mollusks with spiral shells'.