'ammonitoidea' originates from the Latin word 'Ammonites', which was derived from the Greek 'Ammonis', referring to the Egyptian god Ammon, whose horns the shells resembled.

'Ammonites' transformed into the scientific classification 'ammonitoidea' to describe the broader subclass of these creatures.

Initially, it referred to the specific fossilized shells resembling ram's horns, but over time it evolved into its current meaning of a subclass of these extinct mollusks.