Ainoceras

Ainoceras
Temporal range: Campanian[1]
Ainoceras kamuy
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Ancyloceratina
Family: Nostoceratidae
Genus: Ainoceras
Matsumoto & Kanie, 1967

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. However, Ainoceras differed in this respect in that, whereas in Anaklinoceras, the youngest coil wrapped very closely around the older coils, while in Ainoceras, the youngest coil bent over the older coils in a wide loop or oxbow.

  1. ^ Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.