ammoniteyoudaoicibaDictYouDict
ammonite: [18] Like ammonia, the ammonite gets its name from a supposed connection with Amon, or Amen, the Egyptian god of life and reproduction. In art he is represented as having ram’s horns, and the resemblance of ammonites to such horns led to their being named in the Middle Ages cornu Ammōnis ‘horn of Amon’. In the 18th century the modern Latin term ammonītēs (anglicized as ammonite) was coined for them. Earlier, ammonites had been called snake stones in English, a term which survived dialectally well into the 19th century.
ammonite (n.)youdaoicibaDictYouDict
"cephalopod mollusk," 1758, from French (Breyn, 1732), "better established" [Century Dictionary] by French zoologist Jean Guillaume Bruguière (c. 1750-1798) in 1789, from Medieval Latin (cornu) Ammonis "horn of Ammon," the Egyptian god of life and reproduction, who was depicted with ram's horns, which the fossils resemble. The resemblance also was noted in ancient times.