Biota (Life)
Eukaryote (Eukarya)
Podiata
Unikont (Unikonta)
Opisthokont (Opisthokonta)
Holozoa
Filozoa
Apoikozoa (Choanozoa)
Animal (Animalia)
Metazoa
Epitheliozoa
Eumetazoa
Bilateria
Nephrozoa (Eubilateria)
Protostome (Protostomia)
Spiralia (Spiralians)
Lophotrochozoa
Mollusca (Molluscs)
Cephalopod (Cephalopods)
Ammonoidea (Ammonoids)
Ammonitida
Ammonitina
Perisphinctoidea
Pachyceratidae
Erymnoceras
Erymnoceras ajax (23868465)