'ammonitoid' originates from the Greek word 'ammonis,' referring to the horn of Ammon, a ram-headed god, due to the resemblance of the fossil's shape to a ram's horn.

'ammonis' transformed into the Latin word 'ammonites,' and eventually became the modern English word 'ammonitoid' through scientific classification.

Initially, it referred to the shape resembling a ram's horn, but over time it evolved into its current meaning of a specific fossil cephalopod.