 Ainoceras

Ainoceras ("Ainu's Horn") is a genus of extinct, aberrantly coiled ammonite cephalopod that live in the Pacific Ocean during the Campanian division of the Cretaceous, where Japan is today.Their shells were coiled very similarly to the related "Anaklinoceras", in that, when young, the shell coiled helically, and then upon reaching adulthood, the shell then bent over the older coils.