Etymology: < modern Latin ammōnītes (after ætītes , asphaltītes , etc.: see -ite suffix¹), < by Bruguière on the medieval Latin name Cornu Ammonis ‘Ammon's horn,’ given to these fossils from their resemblance to the involuted horn of Jupiter Ammon. At first used as Latin, with plural Ammonitæ.

Etymology: < post-classical Latin Ammonita (Vetus Latina, Vulgate) < Ammon , the name (in Latin) of the son of Lot and founding father of the Ammonites (Vulgate; ultimately < Hebrew ʿAmmōn : see below) + -ita -ite suffix¹.Specific forms. The four-syllable plural form Ammonytees is perhaps after the post-classical Latin plural Ammonites. It is unclear whether the plural form Ammonytes represents a pronunciation with three syllables or four. In the plural form Amanythen in the Wycliffite Bible translating Ammaniten , feminine accusative singular of post-classical Latin Ammanitis (adjective), in the Vulgate (2 Maccabees 4:26). Ulterior etymology of the Latin name. Hebrew ʿAmmōn is only attested in the sense ‘the Ammonites collectively’. The Hebrew name of the biblical patriarch and son of Lot is Ben-ʿAmmī , which is folk-etymologically associated (Genesis 19:38) with ʿam ‘paternal relative’ and explained as ‘son of my (paternal) kindred’, with reference to his origin in an incestuous union of Lot and one of his daughters. Earlier borrowing. With use as noun compare Old English Ammonitare , accusative plural, and Old English Amonitiscra , genitive plural (compare -ish suffix¹), both translating Latin Ammonitarum , genitive plural, in the Vulgate (Genesis 19:38). Compare further Ammonisc of or relating to Ammon (compare -ish suffix¹), also used in the plural as an ethnonym.